Electric toothbrush

Abstract

To provide an electric toothbrush and its coupling structure, in which a head part where toothbrush bristles are located can be used interchangeably. [Solution] The electric toothbrush of the present invention includes a head unit and a handle unit that is detachably coupled to the head unit and supplies a driving voltage to the head unit under the control of a user, and the handle unit includes a base portion, an insert member including one or more protrusions protruding from the base portion, and a plurality of connection terminals positioned such that a portion protrudes outward from the insert member and that are electrically connected to the head unit when the head unit and the handle unit are coupled.

Description

[Technical Field]

[0001] The present invention relates to an electric toothbrush and a coupling structure thereof, and more particularly to an electric toothbrush and a coupling structure thereof that can effectively remove dental plaque. [Background technology]

[0002] Dental plaque is a sticky, transparent film that forms on the surface of teeth. It is formed when numerous bacteria living in the mouth bind to specific components in saliva, and it forms not only on teeth and their surrounding areas, but also on fillings, around orthodontic appliances, and dentures.

[0003] When plaque, which is a very thin and transparent film, is formed, bacteria inside it multiply, and the bacteria in the plaque increase exponentially using the sugars supplied when we eat food. The acidic substances produced by the bacteria in the plaque dissolve the calcification of the teeth, causing cavities, and the toxins act as a cause of inflammation in the gums.

[0004] Plaque itself is difficult to see with the naked eye and occurs mainly in deep grooves in the teeth, between the teeth, and in the narrow spaces between the teeth and gums. Because it causes problems for the teeth and surrounding tissues in such narrow spaces, it is important to thoroughly remove plaque, but the problem is that it is difficult to effectively remove such plaque using only existing toothbrushes. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electric toothbrush and a coupling structure thereof in which the head portion where the toothbrush bristles are located can be replaced.

[0006] Another object of the present invention is to provide an electric toothbrush and its assembly structure that can prevent the occurrence of cavities and periodontal disease by removing dental plaque. [Means for solving the problem]

[0007] The electric toothbrush according to the present invention includes a head unit and a handle unit that is detachably connected to the head unit and supplies a driving voltage to the head unit under control of a user. The handle unit includes a base portion, an insertion member having one or more protrusions protruding from the base portion, and a plurality of connecting terminals that are positioned so that portions protrude outward from the insertion member and are electrically connected to the head unit when the head unit and the handle unit are coupled. The head unit includes a retracted portion that retracts deep enough for the insertion member to be inserted, a separation prevention portion that protrudes from an inner wall surface of the retracted portion and is positioned so that it overlaps with the protrusions when the insertion member is rotated a certain angle while inserted into the retracted portion, a housing member including a plurality of insertion portions formed to penetrate a bottom surface of the retracted portion, and an electrode assembly that is installed adjacent to the housing member inside the head unit and that, when the handle unit and the head unit are coupled, penetrates the plurality of insertion portions and is electrically connected to ends of the plurality of connecting terminals located inside the head unit.

[0008] The handle unit may also include a connection module including a handle housing coupled to the insertion member, a battery installed in the handle housing, a main circuit board on which a signal supply unit that generates a driving voltage using the voltage of the battery is mounted, and a contact block made of a non-conductive material, and contact terminals made of a conductive material and installed to surround the contact block, one side of which contacts the main circuit board and the other side of which contacts each of the plurality of connection terminals.

[0009] The head unit may include a head housing including a head portion having an opening on one side and a coupling portion connected to the head portion, an auxiliary circuit board installed inside the head housing, a head cover closing the opening in the head portion, toothbrush bristles coupled to the head cover, and first and second electrodes located on the auxiliary circuit board at portions corresponding to the head portion and generating an electric field, and the electrode assembly may be located adjacent to a portion of the coupling portion coupled to the handle unit and coupled to the auxiliary circuit board.

[0010] In addition, the electrode assembly may include an insulating member made of a non-conductive material and having a through hole formed therein into which a portion of the auxiliary circuit board is inserted, and a conductive material, one side of which is installed in the insulating member at the portion where the through hole is formed and electrically connected to the auxiliary circuit board, and the other side of which is located adjacent to the receiving member and is electrically connected to the plurality of connecting terminals when the handle unit and the head unit are coupled to each other.

[0011] The conductive member may include a gripping portion that grips a portion of the insulating member where the through hole is formed, a pressing portion that bends or folds onto a portion of the gripping portion that contacts the auxiliary circuit board and presses the auxiliary circuit board, and a contact portion that extends from the gripping portion and contacts the connecting terminal.

[0012] In addition, end portions of the contact portions may be spaced apart from the insulating member, and middle portions of the contact portions may protrude toward the connecting terminals.

[0013] The auxiliary circuit board may have one or more rod-shaped extensions formed thereon so as to be inserted into the through-holes of the insulating member.

[0014] The first and second electrodes may be spaced apart from each other along the length of the auxiliary circuit board.

[0015] The head unit may further include a light emitting element installed on the auxiliary circuit board to emit light to the outside.

[0016] The head cover may be made of a transparent material.

[0017] The handle unit may further include a sealing member located at a portion of the handle housing that contacts the head unit, and that seals the gap between the handle housing and the head unit.

[0018] The plurality of connecting terminals may include a first connecting terminal and one or more second connecting terminals spaced apart from the first connecting terminal.

[0019] The plurality of insertion portions may include a first insertion portion formed to penetrate a bottom surface of the recess portion and allow the first connecting terminal to be electrically connected to the electrode assembly, and one or more second insertion portions formed to penetrate a bottom surface of the recess portion and, when the handle unit and the head unit are rotated relative to each other with the second connecting terminal inserted, are arc-shaped so that the second connecting terminal can move from one end to the other, allowing the second connecting terminal to be electrically connected to the electrode assembly.

[0020] The second insertion portion may be positioned to face a first region in which the one or more second connecting terminals are located and an intermediate portion of the contact portion that protrudes toward the connecting terminals when the insertion member is inserted into the retracted portion of the accommodating member. The second insertion portion may include a position fixing protrusion that protrudes from a portion of the second insertion portion where the second region is located to allow the second connecting terminals to move away from the second region when an external force equal to or greater than a critical value is applied while the second connecting terminals are located in the second region, and allows the second connecting terminals to remain positioned in the second region when an external force equal to or greater than a critical value is not applied.

[0021] The electric toothbrush coupling structure according to the present invention is an electric toothbrush coupling structure including a detachable head unit and a handle unit, wherein the handle unit includes an insertion member having a plurality of protrusions, and a first connecting terminal and a pair of second connecting terminals that pass through the insertion member and are exposed to the outside; the head unit includes a receiving member located at a coupling portion with the handle unit; the receiving member includes a plurality of detachment prevention portions, a first insertion portion located at the center and into which the first connecting terminal is inserted, and a pair of second insertion portions located symmetrically with respect to the first insertion portion and having first and second regions in which the pair of second connecting terminals can be positioned; when the insertion member is initially inserted into the receiving member, the second connecting terminals are positioned in the first region; and when the handle unit is subsequently rotated relative to the head unit, the second connecting terminals located in the first region move to the second region, and the protrusions are inserted into the inside of the detachment prevention portions. [Effects of the Invention]

[0022] According to the present invention described above, it is possible to provide an electric toothbrush in which, when the head unit needs to be replaced, the head unit can be separated from the handle unit and easily replaced with a new head unit.

[0023] According to the present invention, an electric toothbrush capable of effectively removing dental plaque can be provided.

[0024] Furthermore, the present invention provides an electric toothbrush that can prevent the occurrence of cavities and periodontal disease by removing dental plaque.

[0025] Furthermore, the present invention can provide an electric toothbrush in which the connection state between the handle unit and the head unit can be stably maintained.

[0026] Furthermore, the present invention can provide an electric toothbrush that can prevent moisture from entering from the outside. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a perspective view illustrating an electric toothbrush according to an embodiment of the present invention. [Figure 2] 1 is a perspective view illustrating a state in which a head unit and a handle unit included in an electric toothbrush according to an embodiment of the present invention are coupled together; [Figure 3] 2 is a perspective view showing the electric toothbrush shown in FIG. 1 in a separated state. FIG. [Figure 4] FIG. 4 is a view of the handle unit of FIG. 3 as seen from above. [Figure 5] 4 is a cross-sectional view taken along line AA of the handle unit of FIG. 3. [Figure 6] 4 is an exploded perspective view illustrating an insertion member, a main circuit board, a connecting terminal, and a connecting module extracted from the handle unit of FIG. 3. FIG. [Figure 7] FIG. 4 is a diagram illustrating the head unit extracted from FIG. 3. [Figure 8] 6 is a cross-sectional view taken along the line BB of the head unit of FIG. 5. [Figure 9] FIG. 6 is an exploded perspective view illustrating the head unit of FIG. 5. [Figure 10] FIG. 6 is a view of the head unit in FIG. 5 as seen from the Z direction. [Figure 11] 10A to 10C are diagrams illustrating a process of joining an insertion member and a housing member. [Figure 12] 10 is a diagram illustrating an electrode assembly extracted from the head unit of FIG. 9. [Figure 13] 13 is a cross-sectional view taken along line CC of the electrode assembly of FIG. 12. [Figure 14] 1 is a front view of an electric toothbrush according to an embodiment of the present invention; [Figure 15] FIG. 2 is a diagram showing a signal supply unit mounted on a main circuit board. [Figure 16] 3A and 3B are diagrams illustrating signal waveforms according to an embodiment of the present invention. [Figure 17] 3A and 3B are diagrams illustrating signal waveforms according to an embodiment of the present invention. [Figure 18] 3A and 3B are diagrams illustrating signal waveforms according to an embodiment of the present invention. [Figure 19] 10A and 10B are diagrams for explaining the biofilm removal effect of a drive signal generated by mixing an AC signal and a DC signal. [Figure 20] 10A and 10B are diagrams for explaining the biofilm removal effect of a drive signal generated by mixing an AC signal and a DC signal. [Figure 21] FIG. 10 is a diagram illustrating a modified example of the signal supply unit. [Figure 22] FIG. 10 is a diagram illustrating a modified example of the signal supply unit. [Figure 23] 1 is a perspective view illustrating an example of use of an electric toothbrush according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and detailed description of the preferred embodiments. However, the present invention is not limited to the preferred embodiments disclosed below, and may be embodied in various different forms, and all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention are intended to be included.

[0029] In describing components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are used to distinguish the component from other components and do not limit the nature or order of the components. Furthermore, when a component is described herein as being "coupled," "coupled," or "connected" to another component, it should be understood that the component is directly coupled or connected to the other component, but that another component may be "coupled," "coupled," or "connected" between the components. When referring to "coupled," "coupled," or "connected," it should be understood that the terms "coupled," "coupled," or "connected" not only refer to physical "coupled," "coupled," or "connected," but also refer to electrical "coupled," "coupled," or "connected" as necessary.

[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electric toothbrush according to the present invention will now be described in detail with reference to the accompanying drawings.

[0031] FIG. 1 is a perspective view illustrating an electric toothbrush according to an embodiment of the present invention, and FIG. 2 is a perspective view illustrating a state in which a head unit and a handle unit included in the electric toothbrush according to the embodiment of the present invention are combined.

[0032] As shown in FIGS. 1 and 2, an electric toothbrush (1) according to an embodiment of the present invention includes a head unit (100) and a handle unit (200).

[0033] The head unit 100 is inserted at least partially into the user's oral cavity to remove dental plaque. The head unit 100 is detachably connected to a handle unit 200, which will be described later. Therefore, when the head unit 100 needs to be replaced due to aging or other reasons, the user can easily replace the existing head unit 100 with a new head unit 100. A detailed description of the head unit 100 for this purpose will be provided later.

[0034] The handle unit 200 is the main body of the electric toothbrush 1 and is designed to be held by the user during use. The handle unit 200 is detachably connected to the head unit 100 and supplies a driving voltage to the head unit 100 under the control of the user. After a portion of the handle unit 200 is inserted into the head unit 100, when it is rotated relative to the head unit 100, it is electrically connected to and mechanically fastened with the head unit 100.

[0035] 2, with the handle unit 200 and the head unit 100 positioned side by side, the user moves the handle unit 200 in a first direction to insert the end of the handle unit 200 into the head unit 100, and then rotates the handle unit 200 in a second direction, thereby connecting the head unit 100 and the handle unit 200 to each other. The process of separating the handle unit 200 and the head unit 100 is performed in the reverse order of the connecting process.

[0036] Unlike the above-mentioned electric toothbrushes in which the unit 200 and head unit 100 are integrated, if the toothbrush bristles 160 of the head unit 100 become damaged through repeated use, the entire electric toothbrush must be replaced. However, in the electric toothbrush 1 according to the embodiment of the present invention, if the toothbrush bristles 160 of the head unit 100 become damaged through repeated use, the existing head unit 100 can be separated from the handle unit 200 and a new head unit 100 can be attached to the handle unit 200 and used.

[0037] Hereinafter, the handle unit 200 and the head unit 100 included in the electric toothbrush 1 according to the embodiment of the present invention will be described in detail with reference to the drawings.

[0038] 3 is a perspective view showing the electric toothbrush shown in FIG. 1 in a separated state, FIG. 4 is a top view of the handle unit of FIG. 3, FIG. 5 is a cross-sectional view of the handle unit of FIG. 3 taken along line AA, and FIG. 6 is an exploded perspective view showing the insert member, main circuit board, connecting terminal and connecting module extracted from the handle unit of FIG. 3.

[0039] As shown in Figures 3 to 6, the handle unit (200) includes, for example, an insert member (210), a handle housing (220), a battery (230), a main circuit board (240), an operating member (250), a connecting terminal (260), and a connecting module (280).

[0040] The inserting member 210 is inserted into the head unit 100 when the handle unit 200 and the head unit 100 are coupled together. The inserting member 210 for this purpose includes, for example, a base portion 211 and a protruding portion 212.

[0041] The base 211 may be pillar-shaped, for example, cylindrical. A connecting terminal 260 (described later) is installed to penetrate the base 211 and protrude to the outside.

[0042] The protrusions 212 are plate-shaped and include one or more protrusions 212 protruding from the circumferential surface of the base 211. The protrusions 212 protrude from the circumferential surface of the upper side of the base 211. When the handle unit 200 and the head unit 100 are coupled together, the protrusions 212 extend over a portion of the head unit 100, allowing the head unit 100 to be coupled to the handle unit 200. This will be described in detail with the head unit 100.

[0043] The handle housing 220 is coupled to the insert member 210. The handle housing 220 accommodates the battery 230, the main circuit board 240, and the connection terminals 260 and can protect them from external contact.

[0044] The battery 230 may be installed in the handle housing 220 and may supply power to a main circuit board 240, which will be described later. A separate sealing member 270 may be installed in the handle housing 220 for replacing the battery 230, but is not limited to this.

[0045] The battery 230 may be, for example, a primary battery or a secondary battery. If the battery 230 is a primary battery, the user can periodically replace the battery 230. If the battery 230 is a secondary battery, it can be charged using various charging methods.

[0046] For example, the battery 230 can be charged wirelessly or via a wired charging method, or can be separated from the handle housing 220 and charged via a separate charging device.

[0047] The main circuit board 240 can provide a driving voltage, and for this purpose, a signal supply unit (SG1, see FIG. 15) is mounted on the main circuit board 240 to generate the driving voltage using the voltage of the battery 230. A detailed description of the main circuit board 240 for this purpose will be given later.

[0048] The operating member 250 can control the supply of power from the battery 230 to the main circuit board 240. The operating member 250 is installed in a part of the handle housing 220.

[0049] The operating member 250 is, for example, a press button or a touch sensor. When the operating member 250 is a press button, a switch 241 that detects the pressing of the operating member 250 is mounted on the main circuit board 240. When the user presses the operating member 250, the switch 241 detects the pressing of the operating member 250, and the electric toothbrush 1 can be turned on / off.

[0050] When brushing teeth, the user can press the operating member (250) to turn on the power of the electric toothbrush (1), and the driving voltage generated from the handle unit (200) is supplied to the first electrode (110) and / or the second electrode (120) of the head unit (100), thereby generating an electric field for removing plaque.

[0051] The connecting terminal 260 is electrically connected to the main circuit board 240. A portion of the connecting terminal 260 protrudes outward from the insert member 210. That is, in the direction shown in Figure 5, the lower portion of the connecting terminal 260 is electrically connected to the main circuit board 240 and is installed to pass through the insert member 210.

[0052] Here, the connecting terminal 260 may be directly connected to the main circuit board 240, or may be indirectly connected to the main circuit board 240 via a connecting module 280 (described later). The connecting module 280 will be described in detail later. However, the method of connecting the connecting terminal 260 to the main circuit board 240 is not limited to a specific method, as various methods can be used.

[0053] When the head unit (100) and the handle unit (200) are coupled together, the connection terminal (260) is electrically connected to the head unit (100) and the driving voltage of the main circuit board (240) is transmitted to the head unit (100).

[0054] There may be one or more connecting terminals 260. When there are a plurality of connecting terminals 260, the plurality of connecting terminals 260 may include, for example, a first connecting terminal 261 and one or more second connecting terminals 262 spaced apart from the first connecting terminal 261.

[0055] Here, the number of second connecting terminals 262 may be two. In this case, the two second connecting terminals 262A and 262B may be positioned symmetrically with respect to the first connecting terminal 261. The number of connecting terminals 260 may vary depending on the design of the electric toothbrush 1, and is not limited to a specific number.

[0056] Meanwhile, the connecting terminal 260 may be made of a conductive material such as metal and has a rod shape with a predetermined length. The inserting member 210 is made of an insulating material such as non-conductive plastic so as to prevent the first connecting terminal 261 and the plurality of second connecting terminals 262 from being electrically connected to each other.

[0057] The connection module 280 electrically connects the main circuit board 240 and the plurality of connection terminals 260. The connection module 280 includes a contact block 281 and one or more contact terminals 282.

[0058] The contact block 281 is made of a non-conductive material. One portion of the contact block 281 is connected to the main circuit board 240, and the other portion is positioned adjacent to the ends of the connecting terminals 260. The shape of the contact block 281 is, for example, the same as the shape of the insulating member 171 included in the electrode assembly 170, which will be described later, but is not limited to this.

[0059] The contact terminals (282) are made of a conductive material and are installed to surround the contact block (281), with one side contacting the main circuit board (240) and the other side contacting the connecting terminals (260).

[0060] The contact terminal 282 is made of a material that is elastically deformable like a leaf spring, which improves the coupling strength with the contact block 281 and improves contact safety when contacting the connecting terminal 260.

[0061] Meanwhile, the number of contact terminals 282 provided corresponds to the number of connecting terminals 260. For example, if there are three connecting terminals 260, there may also be three contact terminals 282, and the connecting terminals 260 and the contact terminals 282 are in one-to-one correspondence and in contact with each other. The shape of the contact terminals 282 may be the same as that of the conductive member 172 included in the electrode assembly 170, which will be described later, but is not limited thereto.

[0062] The main circuit board 240 and the connection terminal 260 can always maintain a stable electrical connection through the connection module 280. Meanwhile, the handle unit 200 further includes a sealing member 290.

[0063] The sealing member 290 is located at the portion of the handle housing 220 that comes into contact with the head unit 100, and serves to seal the gap between the handle housing 220 and the head unit 100. The sealing member 290 may be ring-shaped and made of rubber or silicone. The sealing member 290 is sandwiched between a portion of the handle housing 220. For example, the sealing member 290 may be located at the portion of the handle housing 220 adjacent to the insert member 210.

[0064] When a user uses the electric toothbrush 1, saliva or toothpaste may leak from the head unit 100. The sealing member 290 prevents substances such as saliva or toothpaste from entering between the handle housing 220 and the head unit 100, thereby preventing damage to the head unit 100 or the handle unit 200 due to moisture.

[0065] Figure 7 is a drawing illustrating an excerpt of the head unit from Figure 3, Figure 8 is a cross-sectional view of the head unit of Figure 5 taken along line BB, Figure 9 is an exploded oblique view illustrating the head unit of Figure 5, Figure 10 is a drawing of the head unit of Figure 5 viewed from the Z direction, and Figure 11 is a diagram for explaining the process of combining the insertion member and the accommodating member.

[0066] As shown in Figures 7 to 11, the head unit (100) includes, for example, a head housing (130), an auxiliary circuit board (140), a first electrode (110), a second electrode (120), a head cover (150), toothbrush bristles (160), an electrode assembly (170), and a receiving member (180).

[0067] The head housing 130 includes a head portion 131 having an opening on one side and a connecting portion 132 communicating with the head portion 131. The head portion 131 and the connecting portion 132 are integrated. The connecting portion 132 can be connected to the handle unit 200, and the head portion 131 can accommodate a head cover 150, toothbrush bristles 160, and a first electrode 110 and a second electrode 120, which will be described later.

[0068] The auxiliary circuit board 140 is installed inside the head housing 130. The auxiliary circuit board 140 has one or more rod-shaped extensions 141 formed thereon so as to be inserted into the through-holes 171a of the insulating member 171. The number of extensions 141 corresponds to the number of connecting terminals 260. For example, if the connecting terminal 260 includes one first connecting terminal 261 and two second connecting terminals 262, the number of extensions 141 is three. A conductive line (not shown) may be formed on each extension 141, and each conductive line is electrically connected to the connecting terminal 260 through an electrode assembly 170 (described below).

[0069] The head cover 150 closes the opening in the head part 131. To do so, the head cover 150 is shaped to correspond to the opening in the head part 131. The toothbrush bristles 160 are attached to the head cover 150. The toothbrush bristles 160 are inserted and fixed into a number of bristle holes (not shown) formed on the outer surface of the head cover 150. The arrangement, number, size, etc. of the toothbrush bristles 160 are not particularly limited and can be changed in various forms.

[0070] The first electrode 110 and the second electrode 120 are located on the auxiliary circuit board 140 at a position corresponding to the head portion 131 to generate an electric field. The first electrode 110 and the second electrode 120 are mounted on the auxiliary circuit board 140.

[0071] The first electrode (110) and the second electrode (120) generate an electric field when supplied with electrical energy from the handle unit (200). This electric field weakens the structure of dental plaque, allowing the user to effectively remove dental plaque from the oral cavity using the electric toothbrush (1) according to the embodiment of the present invention.

[0072] For this reason, the first electrode (110) and the second electrode (120) are formed of materials such as brass, aluminum, conductive polymer, conductive silicon, stainless steel, etc., but are not limited to these, and any material having conductivity can be used as the electrode material.

[0073] The first electrode 110 and the second electrode 120 are set as a positive electrode and a negative electrode, respectively. The first electrode 110 and the second electrode 120 protrude outward from the head cover 150 to a predetermined height. The height of the first electrode 110 and the second electrode 120 can be changed depending on the design of the electric toothbrush 1 and is not limited to a specific value.

[0074] The electrode assembly 170 is installed adjacent to the receiving member 180 inside the head unit 100, and when the handle unit 200 and the head unit 100 are coupled, it passes through the insertion portions 184, 185 and is electrically connected to end portions of the connecting terminals 260 located inside the head unit 100. For this purpose, the electrode assembly 170 is located adjacent to the portion of the coupling portion 132 that is coupled to the handle unit 200, and is coupled to the auxiliary circuit board 140.

[0075] That is, the auxiliary circuit board 140 receives the driving voltage transmitted from the handle unit 200 from the electrode assembly 170 and transmits it to the first electrode 110 and the second electrode 120. The electrode assembly 170 will be described in detail later.

[0076] The receiving member 180 is positioned adjacent to the electrode assembly 170 and is connected to the end portion of the connecting portion 132 that is connected to the handle unit 200. The receiving member 180 is fastened to the electrode assembly 170 or the head housing 130 by a separate bolt 186. When the handle unit 200 and the head unit 100 are connected, the receiving member 180 is mechanically fastened to the handle unit 200.

[0077] In addition, the receiving member 180 exposes a portion of the electrode assembly 170 to the outside, so that the connecting terminal 260 can penetrate the receiving member 180 and contact the electrode assembly 170, as will be described in detail below.

[0078] Meanwhile, the receiving member 180 includes, for example, a retracting portion 181, a separation prevention portion 182, and a plurality of insertion portions 184, 185. The retracting portion 181 is retracted to a depth that allows the insertion member 210 to be inserted. The separation prevention portion 182 is plate-shaped and protrudes from the inner wall surface of the retracting portion 181. When the insertion member 210 is inserted into the retracting portion 181 and rotated a certain angle, the plate-shaped ...

[0079] The insertion portions (184, 185) are formed to penetrate the bottom surface of the retraction portion (181), and when the handle unit (200) and the head unit (100) rotate relative to each other with the connection terminals (260) inserted, they are mechanically coupled to the connection terminals (260). The head unit (100) and the handle unit (200) are mechanically coupled to each other by coupling the insertion portions (184, 185) and the connection terminals (260).

[0080] Meanwhile, the receiving member (180) further includes a support portion (183).

[0081] The support portion 183 protrudes from the inner wall surface of the retraction portion 181. The support portion 183 supports the peripheral surface of the base portion 211 to improve the fixing force to the base portion 211. In addition, when the handle unit 200 moves in the first direction toward the head unit 100 (see FIG. 2), the support portion 183 allows the protrusion 212 of the insertion member 210 to be inserted into the region M of the retraction portion 181, preventing it from being inserted into other regions.

[0082] Meanwhile, the head unit 100 further includes a light emitting element 190. The light emitting element 190 is installed on the auxiliary circuit board 140 and emits light to the outside.

[0083] In this case, the head cover 150 included in the head unit 100 is made of a transparent material. For example, the material of the head cover 150 can be polycarbonate or an acrylic plate that diffuses light. The outer surface of the head cover 150 has small protrusions formed thereon to facilitate light diffusion. The head housing 130 can also be made of a transparent material, allowing the head unit 100 to emit light when the electric toothbrush 1 is in operation.

[0084] Meanwhile, one of the three connecting terminals 260 is connected to the ground terminal of the main circuit board 240, the other receives a driving voltage for generating an electric field from the main circuit board 240, and the remaining one receives power from the main circuit board 240 to drive the light emitting element 190. For example, one of the two second connecting terminals 262 is connected to the ground terminal of the main circuit board 240, and the remaining one receives the driving voltage from the main circuit board 240. Also, the first connecting terminal 261 receives power from the main circuit board 240 and transmits it to the light emitting element 190.

[0085] Meanwhile, as described above, the receiving member 180 allows the connection terminal 260 included in the handle unit 200 to pass through, thereby electrically connecting with the head unit 100. To explain the receiving member 180 in more detail, the receiving member 180 includes a first insertion portion 184 and a second insertion portion 185.

[0086] The first insertion portion (184) is formed to penetrate the bottom surface of the recess (181) to electrically connect the first connecting terminal (261) to the electrode assembly (170). The second insertion portion (185) is formed to penetrate the bottom surface of the recess (181). The second insertion portion (185) is arc-shaped so that the second connecting terminal (262) can move from one end to the other when the handle unit (200) and the head unit (100) rotate relative to each other with the second connecting terminal (262) inserted. More specifically, the shape of the second insertion portion (185) has a curvature radius corresponding to the movement path of the second connecting terminal (262) and a width greater than the diameter of the second connecting terminal (262). The second insertion portion (185) allows the second connecting terminal (262) to be electrically connected to the electrode assembly (170).

[0087] There may be one or more second insertion portions (185). If there are two second connecting terminals (262), there may also be two second insertion portions (185). The two second insertion portions (185) are formed symmetrically with respect to the first insertion portion (184). When the handle unit (200) and the head unit (100) are coupled, each of the two second connecting terminals (262) passes through each of the two second insertion portions (185) and contacts the electrode assembly (170). And, the first connecting terminal (261) passes through the first insertion portion (184) and contacts the electrode assembly (170).

[0088] The process of inserting the inserting member 210 into the receiving member 180 and connecting the handle unit 200 and the head unit 100 will be described below.

[0089] First, returning to FIG. 2, with the handle unit (200) and the head unit (100) positioned side by side, the user moves the handle unit (200) in a first direction to insert the end portion of the handle unit (200) into the head unit (100).

[0090] 10, the second insertion portion 185 includes a first region 185a, a second region 185b, and a position fixing protrusion 185c. The first region 185a is the region where the one or more second connecting terminals 260 are located when the insertion member 210 is inserted into the retracted portion 181 of the receiving member 180. As described above, the protrusion 212 of the insertion member 210 is inserted into the M region, which is the insertion target region, without being inserted into other regions of the receiving member 180 due to the support portion 183, so that the second connecting terminals 262 can be located in the first region 185a of the second insertion portion 185.

[0091] The second region 185b is a region where the one or more second connecting terminals 260 move from the first region 185a and are finally positioned when the insertion member 210 is rotated a certain angle while inserted into the retracted portion 181 of the receiving member 180, as shown in Fig. 11. The second region 185b is positioned to face the middle portion of the contact portion 172c that protrudes toward the connecting terminals 260.

[0092] As a result, when the second connecting terminal (260) is positioned in the second region (185b), it presses the middle portion protruding from the contact portion (172c), causing the contact portion (172c) to elastically deform and maintain strong contact with the second connecting terminal (260).

[0093] The position fixing protrusion 185c protrudes from a portion of the second insertion portion 185 where the second region 185b is located, allowing the second connecting terminal 262 to separate from the second region 185b when an external force greater than or equal to a critical value is applied while the second connecting terminal 262 is located in the second region 185b, and allowing the second connecting terminal 262 to remain positioned in the second region 185b when an external force greater than or equal to the critical value is not applied. The position fixing protrusion 185c ensures stable connection between the second connecting terminal 262 and the receiving member 180.

[0094] Next, when the user rotates the handle unit (200) in a second direction (clockwise) (see FIG. 2), the head unit (100) rotates counterclockwise relative to the handle unit (200).

[0095] When the insertion member 210 is rotated and the second connecting terminal 262 is positioned in the second region 185b of the second insertion portion 185, the insertion member 210 stops rotating. At this time, the protrusions 212 are inserted into the inside of the separation prevention portions 182, and the separation prevention portions 182 and the protrusions 212 overlap each other. That is, the protrusions 212 located on both sides of the insertion member 210 are engaged with the inside of the corresponding separation prevention portions 182 of the receiving member 180, so that the handle unit 200 and the head unit 100 will not separate from each other even if the user pulls them lengthwise.

[0096] Figure 12 is a view illustrating an electrode assembly extracted from the head unit of Figure 9, and Figure 13 is a cross-sectional view taken along line CC of the electrode assembly of Figure 12. Referring to Figures 12 and 13, the electrode assembly 170 includes, for example, an insulating member 171 and a conductive member 172.

[0097] The insulating member 171 is made of a non-conductive material and has a through hole 171a formed therein, into which a portion of the auxiliary circuit board 140 is inserted. The conductive member 172 is made of a conductive material and has one side disposed at the portion of the insulating member 171 where the through hole 171a is formed and electrically connected to the auxiliary circuit board 140 through an extension 141 inserted into the through hole 171a, and the other side disposed adjacent to the receiving member 180 and electrically connected to the plurality of connecting terminals 260 when the handle unit 200 and the head unit 100 are coupled to each other. There may be one or more conductive members 172.

[0098] When there are a plurality of conductive members 172, the conductive members 172 are spaced apart from one another. The conductive members 172 may have a ribbon shape, for example, and may be bent multiple times.

[0099] The conductive member 172 is made of a material that is elastically deformable like a leaf spring, thereby improving the bonding strength with the insulating member 171 and improving contact safety when contacting the connecting terminal 260.

[0100] The number of conductive members 172 provided corresponds to the number of connecting terminals 260. For example, if there are three connecting terminals 260, there may also be three conductive members 172, and the connecting terminals 260 and the conductive members 172 are in one-to-one correspondence and in contact with each other.

[0101] Meanwhile, insulating member 171 is formed with spacing portions 171c and locking jaws 171b to prevent contact between adjacent conductive members 172. Separating portions 171c protrude from the outer surface of insulating member 171 to be positioned between adjacent conductive members 172. Locking jaws 171b are inserted into installation holes H formed in conductive members 172 when conductive members 172 are coupled to insulating member 171.

[0102] The conductive member 172 is continuously maintained in its initial position by the spacing portion 171c and the locking jaw 171b. The conductive member 172 includes, for example, a gripping portion 172a, a pressure portion 172b, and a contact portion 172c.

[0103] The gripping portion 172a grips the insulating member 171 at the portion where the through-hole 171a is formed. The gripping portion 172a may have a U-shape, for example, but is not limited to this. The installation hole H is formed to pass through the gripping portion 172a.

[0104] The pressure portion 172b is bent or folded over the portion of the gripping portion 172a that contacts the auxiliary circuit board 140, thereby applying pressure to the auxiliary circuit board 140. The pressure portion 172b may have an arc shape and is formed at the portion of the gripping portion 172a where the through-hole 171a is located.

[0105] During the process of assembling the head unit 100, a portion of the auxiliary circuit board 140 (e.g., extension 141) can be inserted into the through-hole 171a of the insulating member 171, and the pressure member 172b presses the auxiliary circuit board 140. As a result, the pressure member 172b is electrically connected to an electrode pattern (not shown) formed on the auxiliary circuit board 140. In other words, the pressure member 172b not only improves the bonding strength between the auxiliary circuit board 140 and the electrode assembly 170, but also electrically connects the auxiliary circuit board 140 and the conductive member 172.

[0106] The contact portion 172c extends from the grip portion 172a and contacts the connecting terminal 260. The end of the contact portion 172c is not fixed and is spaced apart from the insulating member 171. When the handle unit 200 and the head unit 100 are connected, even if the connecting terminal 260 presses the contact portion 172c, a portion of the contact portion 172c is deformed, thereby reducing the load on the connecting terminal 260. Furthermore, when the handle unit 200 and the head unit 100 are connected, stable contact between the connecting terminal 260 and the conductive member 172 is maintained.

[0107] The middle portion of the contact portion 172c protrudes toward the plurality of connecting terminals 260. When the handle unit 200 and the head unit 100 are coupled, the contact portion 172c is elastically deformed to generate an elastic force, thereby further improving the contact reliability between the connecting terminals 260 and the contact portion 172c.

[0108] As described above, the head unit 100 does not use wires for electrical connection between the first electrode 110, the second electrode 120, and the electrode assembly 170, but the auxiliary circuit board 140 is directly connected to the electrode assembly 170. Therefore, during the process of assembling the head unit 100, the worker does not need to perform the task of placing wires inside the head unit 100, making the assembly process easier.

[0109] Furthermore, unlike the above, when connecting components using electric wires, a short circuit may occur at the connection between the electric wire and the components, or a break may occur inside the electric wire, causing the electric toothbrush to operate. However, in the head unit 100 included in the electric toothbrush 1 according to an embodiment of the present invention, the auxiliary circuit board 140 and the electrode assembly 170 are mechanically fastened to each other, thereby preventing the occurrence of such problems.

[0110] 14 is a front view of an electric toothbrush according to an embodiment of the present invention. As shown in FIG. 14, in the head unit 100, the first electrode 110 and the second electrode 120 are spaced apart from each other along the length of the auxiliary circuit board 140. That is, based on the direction shown in the drawing, the first electrode 110 and the second electrode 120 can be positioned side by side on an imaginary reference line.

[0111] The toothbrush bristles (160) are arranged more densely in the middle of the head cover (150) than at the top and bottom ends for effective plaque removal, and bristle holes (not shown) are unlikely to be formed around the areas of the head cover (150) where the first electrode (110) and second electrode (120) are located.

[0112] Therefore, unlike the above, when the first electrode (110) and the second electrode (120) are arranged parallel to each other in the left-right direction, more space is wasted in the middle of the head cover (150) than when the first electrode (110) and the second electrode (120) are arranged side by side on an imaginary reference line. Therefore, more bristle implantation holes can be formed in the head cover (150), making it relatively difficult to densely install the toothbrush bristles (160).

[0113] However, when the first electrode (110) and the second electrode (120) included in the head unit (100) of the electric toothbrush (1) according to an embodiment of the present invention are positioned so as to be spaced apart from each other along the longitudinal direction of the auxiliary circuit board (140), the toothbrush bristles (160) are arranged relatively closely to the head cover (150), thereby further improving the plaque removal effect.

[0114] Figure 15 is a diagram showing a signal supply unit included in the main circuit board, and Figures 16 to 18 are diagrams showing signal waveforms according to an embodiment of the present invention. In particular, Figure 16 shows a filtered AC signal (Sac'), Figure 17 shows a DC signal (Sdc), and Figure 18 shows a driving signal (Vd) generated by mixing the filtered AC signal (Sac') and the DC signal (Sdc). In addition, Figures 19 and 20 are diagrams for explaining the biofilm removal effect of a driving signal generated by mixing an AC signal and a DC signal.

[0115] 15, the signal supply unit SG1 is mounted on the main circuit board 240 (see FIG. 5) and generates a driving signal Vd using a battery voltage Vb supplied from the battery 230. In particular, the signal supply unit SG1 can generate the driving signal Vd by mixing an alternating current (AC) signal and a direct current (DC) signal.

[0116] As a result, the drive signal (Vd) contains both AC and DC components, and the simultaneous application of the AC and DC components creates a synergistic effect and resonance, which increases the effectiveness of removing biofilm, which causes bacterial film on the tongue and palate.

[0117] As shown in Figure 19, the electric field generated by the DC component induces an imbalance in the local charge distribution, increasing the structural stress of the biofilm, while the electric field generated by the AC component increases the permeability of the outer protective layer by generating specific vibrations. This synergistic effect of the AC and DC components can be seen in Figure 20. In other words, compared to the biofilm removal effect when the electric field generated by the AC component and the electric field generated by the DC component are applied separately, the biofilm removal effect is significantly higher when the electric field generated by the AC component and the electric field generated by the DC component are applied simultaneously in a superimposed state.

[0118] According to an embodiment of the present invention, the driving signal (Vd) supplied by the signal supply unit (SG1) provides an electric field with a DC component and an electric field with an AC component through the electric field generating member, thereby achieving the amplified removal effect associated with the biofilm described above.

[0119] In addition, since the drive signal (Vd) is set in the form of AC voltage and DC voltage superimposed as described above, the risk of electric shock to the body and the pain that may be induced in the body are reduced compared to when only DC voltage is applied.

[0120] Meanwhile, the signal supply unit (SG1) may include, for example, a DC-DC converter (SG1a), a signal generating unit (SG1b), a filter (SG1c), and a calibration unit (SG1d), and may further include a voltage dividing unit (SG1e).

[0121] The DC-DC converter (SG1a) receives the battery voltage (Vb) and converts it into an output voltage (Vo) of a predetermined level for output. The signal generator (SG1b) operates based on the voltage supplied from the DC-DC converter (SG1a) and generates an AC signal (Sac) having a predetermined frequency using the output voltage (Vo) of the DC-DC converter (SG1a).

[0122] The signal generating unit SG1b can be realized using a known configuration capable of generating an AC signal, such as an oscillator, a function generator, etc.

[0123] For example, the AC signal (Sac) is set to a frequency of 1 kHz to 1000 MHz. This is because if the AC signal (Sac) is set to a low frequency below 1 kHz, the biofilm removal effect will decrease, and if the AC signal (Sac) is set to an ultra-high frequency above 1000 MHz, the biofilm removal effect will also decrease. On the other hand, the frequency of the AC signal (Sac) is set to a frequency of 5 MHz to 15 MHz, which is suitable for removing biofilms.

[0124] In addition, the amplitude of the AC signal (Sac) is set to 0.1mV to 3V. If the amplitude of the AC signal (Sac) is less than 0.1mV, it is difficult to expect a biofilm removal effect, and if the amplitude of the AC signal (Sac) exceeds 3V, there is a risk of toxic substances being generated due to electrolysis of body fluids.

[0125] The filter (SG1c) performs a filtering operation on the AC signal (Sac) generated by the signal generator (SG1b). For example, the filter (SG1c) includes a band pass filter and converts the AC signal (Sac) in a sawtooth wave form into an AC signal (Sac') in a sine wave form. However, the type of the filter (SG1c) is not limited to this, and various types of filters can be used depending on the design structure.

[0126] The calibration unit (SG1d) generates the drive signal (Vd) by mixing the DC signal (Sdc) with the AC signal (Sac') supplied through the filter (SG1c). For example, the calibration unit (SG1d) can be implemented as an operating amplifier capable of adding (or superimposing) the AC signal (Sac') and the DC signal (Sdc), but is not limited thereto.

[0127] As a result, an offset corresponding to the DC signal (Sdc) occurs in the AC signal (Sac'), generating a drive signal (Vd) that contains both AC and DC components. Since the drive signal (Vd) contains all the characteristics of the AC signal (Sac), the drive signal (Vd) can be set to a frequency of 1KHz to 1000MHz, and is also set to a frequency of 5MHz to 15MHz, which is more suitable for removing biofilms. The amplitude of the drive signal (Vd) is set to 0.1mV to 3V.

[0128] Referring to FIG. 16, the calibration unit (SG1d) can receive an AC signal (Sac') having an amplitude of A volts (V) from the filter (SG1c), and can generate the final drive signal (Vd) shown in FIG. 18 by superimposing a DC signal (Sdc) of B volts (V) shown in dot 17 on the corresponding AC signal (Sac').

[0129] In this case, the voltage value of the DC signal (Sdc) is set to be greater than or equal to the amplitude of the AC signal (Sac'). Therefore, the voltage value of the driving signal (Vd) is set to be greater than or equal to 0. As a result, the DC offset value of the driving signal (Vd) is set to be equal to or greater than the amplitude of the driving signal (Vd).

[0130] When the DC offset value of the driving signal (Vd) is less than the amplitude value of the driving signal (Vd), a section occurs in which the voltage of the driving signal (Vd) has a nominal value, and as the voltage has a nominal value in this section, a loss of electrical energy occurs.

[0131] However, if the DC offset value of the driving signal (Vd) is set to be equal to or greater than the amplitude of the driving signal (Vd), as in the embodiment of the present invention, the voltage of the driving signal (Vd) is always greater than '0', thereby minimizing the loss of electrical energy. Meanwhile, the DC signal (Sdc) is generated by the voltage divider unit (SG1e). For example, the voltage divider unit (SG1e) receives the output voltage (Vo) of the DC-DC converter (SG1a) and performs voltage division on the output voltage (Vo) to generate the DC signal (Sdc).

[0132] The voltage divider (SG1e) is configured as, but not limited to, a resistor string for dividing the output voltage (Vo). If the output voltage (Vo) of the DC-DC converter (SG1a) is suitable for immediate use in generating the drive signal (Vd), the output voltage (Vo) serves as the DC signal (Sdc). In this case, the voltage divider (SG1e) can be omitted, and the output voltage (Vo) of the DC-DC converter (SG1a) is input to the calibration unit (SG1d).

[0133] 21 and 22 are diagrams illustrating modified examples of the signal supply unit. Referring to Fig. 21 and Fig. 22, the signal supply unit (SG2) according to the modified example includes a DC-DC converter (SG2a), a signal generating unit (SG2b), a voltage drop unit (SG2e), a filter (SG2c), and an offset adjusting unit (SG2d).

[0134] The DC-DC converter SG2a receives the battery voltage Vb from the battery 230, converts the battery voltage Vb into an output voltage Vo of a predetermined level, and outputs the converted voltage.

[0135] The signal generating unit (SG2b) operates based on the voltage supplied from the DC-DC converter (SG2a) and generates a first AC signal (Sa1) having a predetermined frequency using the output voltage (Vo) of the DC-DC converter (SG2a).

[0136] The signal generating unit (SG2b) can be implemented using a known configuration capable of generating an AC signal, such as an oscillator, a function generator, etc. For example, the first AC signal (Sa1) is set to a frequency of 1 KHz to 1000 MHz. This is because if the first AC signal (Sa1) is set to a low frequency below 1 KHz, the biofilm removal effect is reduced, and if the first AC signal (Sa1) is set to an ultra-high frequency above 1000 MHz, the biofilm removal effect is also reduced. Meanwhile, the frequency of the first AC signal (Sa1) is set to a frequency of 5 MHz to 15 MHz, which is suitable for biofilm removal.

[0137] The voltage drop unit SG2e is used to reduce the magnitude (e.g., peak-to-peak voltage) of the first AC signal Sa1 output from the signal generating unit SG2b. For example, the voltage drop unit SG2e can be implemented with a resistor R, through which the second AC signal Sa2, which has a reduced magnitude compared to the first AC signal Sa1, is supplied from the voltage drop unit SG2e.

[0138] The filter SG2c performs a filtering operation on the second AC signal Sa2 output from the voltage drop unit SG2e. For example, the filter SG2c may be configured as a low pass filter including a large capacitor element C, and converts the second AC signal Sa2 in the form of a sawtooth wave into a third AC signal Sa3 in the form of a sine wave.

[0139] In addition, the filter SG2c removes any unexpected DC offset from the second AC signal Sa2, improving the precision of the drive signal Vd. The offset adjuster SG2d generates the drive signal Vd by mixing the DC signal with the third AC signal Sa3 output from the filter SG2c. For example, the offset adjuster SG2d may include a number of resistors R1 and R2, and may perform voltage division on the output voltage Vo of the DC-DC converter SG2a to generate a DC signal of a predetermined level.

[0140] That is, the third AC signal Sa3 supplied through the filter SG2c is superimposed on the DC signal generated at the common node N of the first resistor R1 and the second resistor R2 to generate the final driving signal Vd.

[0141] In this case, the amplitude of the drive signal (Vd) is set to 0.1 mV to 3 V. If the amplitude of the drive signal (Vd) is less than 0.1 mV, it is difficult to expect a biofilm removal effect, and if the amplitude of the drive signal (Vd) exceeds 3 V, there is a risk of toxic substances being generated due to electrolysis of body fluids.

[0142] 23 is a perspective view illustrating an example of how to use an electric toothbrush according to an embodiment of the present invention. Referring to FIG. 23, when a user is not using an electric toothbrush 1 according to an embodiment of the present invention, the user stores the electric toothbrush 1 by attaching a protective gap 400 to the head unit 100. When the user carries and uses the electric toothbrush 1, the protective gap 400 protects the toothbrush bristles 160 from external contaminants such as dust and foreign objects.

[0143] When the electric toothbrush 1 according to the embodiment of the present invention needs to be charged, the user places the electric toothbrush 1 in the charger 300. At this time, the battery 230 is charged wirelessly or via a wired charging method.

[0144] On the other hand, if the electric toothbrush (1) is a wired charging type, a charging terminal is provided on the outside of the handle unit (200) and a charging terminal is also provided on the charger (300) so that the terminals are in contact with each other. Alternatively, if the electric toothbrush (1) is a wired charging type, electromagnetic (magnetic field) induction using a coil, resonance using self-resonance, or radio frequency (RF) / microwave radiation, which converts electrical energy into microwaves and transmits them, is used.

[0145] The self-resonance method utilizes the self-resonance (current state of magnetic resonance) between a transmitting coil module (Tx) and a receiving coil module (Rx), and is a method in which the transmitting coil module (Tx) is placed in the charger (300) and the receiving coil module (Rx) is placed in the electric toothbrush (1) to transmit power between the coils.

[0146] It should be understood by those skilled in the art that the present invention can be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. Therefore, the above-described embodiments should be understood to be illustrative in all respects and not limiting. The scope of the present invention is defined by the claims that follow rather than the above description, and all modifications and variations that fall within the meaning and scope of the claims and their equivalents should be understood to be included in the scope of the present invention. [Explanation of symbols]

[0147] 1 electric toothbrush 100 head unit 110 1st electrode 120 2nd electrode 130 Head housing 131 Head 132 Joint 140 Auxiliary Circuit Board 141 Extension 150 head cover 160 toothbrush bristles 170 Electrode assembly 171 Insulating materials 171a Through Hole 171b Locking jaw 171c Separation part 172 Conductive materials 172a Grip 172b Pressure section 172c Contact part 180 Storage member 181 Retraction section 182 Anti-detachment section 183 Support part 184 First Insertion Section 185 Second Insertion Section 185a 1st area 185b Second area 185c position fixing protrusion 186 volts 190 Light-emitting element 200 Handle unit 210 Insertion member 211 Base 212 Protrusion 220 Handle Housing 230 Battery 240 Main Circuit Board 241 Switch 250 Operating member 260 Connecting terminal 261 1st connection terminal 262 2nd connection terminal 262A 2nd connection terminal 262B 2nd connection terminal 270 Sealing member 280 Connecting Module 281 Contact Block 282 Contact terminal 290 Sealing materials 300 charger 400 Protection Gap H Installation Hall SG1 signal supply section SG1a DC-DC Converter SG1b signal generator SG1c filter SG1d calibration section SG1e Voltage distribution unit SG2 signal supply section SG2a DC-DC Converter SG2b signal generator SG2c filter SG2d offset adjustment part SG2e voltage drop section Vb Battery voltage Vd drive signal

Claims

1. Head unit, and a handle unit detachably coupled to the head unit and configured to supply a driving voltage to the head unit under the control of a user; The handle unit includes: an insert member including a base portion and one or more projections projecting from the base portion; and a plurality of connection terminals, a portion of which protrudes outward from the insertion member and which are electrically connected to the head unit when the head unit and the handle unit are coupled together; The head unit includes: a receiving member including a retracting portion retracted to a depth at which the insertion member can be inserted; a separation prevention portion protruding from an inner wall surface of the retracting portion and positioned so as to overlap with the protruding portion when the insertion member is rotated by a predetermined angle while inserted into the retracting portion; and a plurality of insertion portions formed to penetrate a bottom surface of the retracting portion; an electrode assembly that is installed adjacent to the receiving member inside the head unit and that penetrates the insertion portions and is electrically connected to end portions of the plurality of connecting terminals located inside the head unit when the handle unit and the head unit are coupled, the handle unit includes a handle housing coupled to the insertion member, a battery installed in the handle housing, a main circuit board on which a signal supply unit for generating a driving voltage using a voltage of the battery is mounted, and a connection module including a contact block made of a non-conductive material and contact terminals made of a conductive material and installed to surround the contact block, one side of which contacts the main circuit board and the other side of which contacts each of the plurality of connection terminals, the head unit includes a head housing including a head portion having an opening at one side and a coupling portion communicating with the head portion, an auxiliary circuit board installed inside the head housing, a head cover closing the opening at the head portion, toothbrush bristles coupled to the head cover, and first and second electrodes positioned at portions of the auxiliary circuit board corresponding to the head portion and generating an electric field, the electrode assembly is located adjacent to a portion of the coupling portion that is coupled to the handle unit, and is coupled to the auxiliary circuit board; the electrode assembly includes: an insulating member made of a non-conductive material, the insulating member having a through hole formed therein, into which a portion of the auxiliary circuit board is inserted; and a conductive member made of a conductive material, the conductive member having one side disposed at the portion of the insulating member where the through hole is formed and electrically connected to the auxiliary circuit board, and the other side positioned adjacent to the receiving member, the conductive member being electrically connected to the plurality of connecting terminals when the handle unit and the head unit are coupled to each other. the conductive member includes: a gripping portion that grips a portion of the insulating member where the through hole is formed; a pressing portion that bends or folds onto a portion of the gripping portion that contacts the auxiliary circuit board and presses the auxiliary circuit board; and a contact portion that extends from the gripping portion and contacts the connecting terminal.

2. An end portion of the contact portion is spaced apart from the insulating member, The electric toothbrush of claim 1 , wherein the middle portion of the contact portion protrudes toward the plurality of connecting terminals.

3. 2. The electric toothbrush of claim 1, wherein the auxiliary circuit board has one or more rod-shaped extensions that can be inserted into the through-holes of the insulating member.

4. 2. The electric toothbrush of claim 1, wherein the first electrode and the second electrode are spaced apart from each other along the length of the auxiliary circuit board.

5. The head unit includes:

2. The electric toothbrush of claim 1, further comprising a light emitting element disposed on the auxiliary circuit board for emitting light to the outside.

6. 2. The electric toothbrush according to claim 1, wherein the head cover is made of a transparent material.

7. The handle unit includes:

2. The electric toothbrush of claim 1, further comprising a sealing member located at a portion of the handle housing that contacts the head unit, for sealing between the handle housing and the head unit.

8. The plurality of connecting terminals are a first connecting terminal, and 3. The electric toothbrush of claim 2, further comprising one or more second connecting terminals spaced apart from the first connecting terminals.

9. The plurality of insertion sections include:

10. The electric toothbrush of claim 8, further comprising: a first insertion portion formed to penetrate a bottom surface of the recessed portion and allowing the first connecting terminal to be electrically connected to the electrode assembly; and one or more second insertion portions formed to penetrate a bottom surface of the recessed portion and having an arc shape so that the second connecting terminal can move from one end to the other when the handle unit and the head unit are rotated relative to each other with the second connecting terminal inserted therein, allowing the second connecting terminal to be electrically connected to the electrode assembly.

10. The second insertion portion is a first region in which the one or more second connecting terminals are located when the insertion member is inserted into the retracted portion of the receiving member; 10. The electric toothbrush of claim 9, further comprising: a second region in which the one or more second connecting terminals move from the first region and are finally positioned when the insertion member is rotated a certain angle while inserted into the retracted portion of the receiving member; and a position fixing protrusion protruding from a portion of the second insertion portion where the second region is positioned so that the second connecting terminal can be released from the second region when an external force equal to or greater than a critical value is applied when the second connecting terminal is positioned in the second region, and so that the second connecting terminal remains positioned in the second region when an external force equal to or greater than the critical value is not applied.

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