ultrasonic toothbrush

Abstract

To identify a frequency of an ultrasonic wave used for an ultrasonic toothbrush.SOLUTION: An ultrasonic toothbrush at least includes: a grip part having a signal generation part for outputting a drive signal supplied to a vibrator for emitting an ultrasonic wave; a vibration part where the vibrator is arranged; and a brush arranged at a position opposed to the vibration part, to which the ultrasonic wave emitted from the vibrator is supplied. The vibration part includes a space part, and the space part includes a pedestal part having the vibrator inserted into an adhesive put in the space part and pressing means for arranging the vibrator. The vibrator is pressed in a direction to get closer to the brush by the pressing means. A frequency of the drive signal is 3-5 MHz.SELECTED DRAWING: Figure 6B

Description

[Technical Field]

[0001] The present invention relates to electric toothbrushes, and more particularly to ultrasonic electric toothbrushes. [Background technology]

[0002] Electric toothbrushes that vibrate the brush during brushing to improve brushing effectiveness, including plaque removal and cleaning (hereinafter simply referred to as brushing effectiveness), have been put into practical use. Furthermore, ultrasonic toothbrushes that use ultrasound to improve brushing efficiency and achieve good tooth brushing have been proposed, for example, in Patent Document 1. The frequency of the ultrasound used in ultrasonic toothbrushes is usually around 1 MHz to 2 MHz, for example, 1.6 MHz, as in Patent Documents 2 and 3. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-61985 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-102837 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-202065 Summary of the Invention [Problem to be solved by the invention]

[0004] It has been confirmed that ultrasonic toothbrushes offer superior brushing effects unique to ultrasonic technology compared to non-ultrasonic toothbrushes. However, the frequency that provides the best brushing effect has not yet been fully explored, and even if one wanted to improve efficiency and create a more suitable toothbrush, it was unclear what frequency to set.

[0005] Furthermore, as the ultrasonic frequency increases, the vibrator becomes thinner, making it more susceptible to damage due to the load applied to the vibrator when it is mounted on a toothbrush, resulting in a high defect rate. For example, when a vibrator is moved from a position other than the designated position to the correct position, excessive force is applied to the vibrator, which can cause the vibrator to break or crack, making it more susceptible to damage. This tendency is more pronounced when placing the vibrator using a method such as that described in Patent Document 1, where the vibrator is moved within a filling material, such as an adhesive. Therefore, to avoid damage to the vibrator, the vibrator may be fixed in place even if it is placed in a position other than the designated position. Because the vibrator is not positioned in the designated position, the desired ultrasonic waves are not necessarily transmitted to the toothbrush, resulting in insufficient brushing effectiveness.

[0006] Or, even if the transducer is in the predetermined position, it is likely to be fixed with excessive force applied, and for example, if the transducer is fixed in a curved state, the transducer may not be able to output the predetermined ultrasonic waves. Furthermore, if the transducer is easily attached to a location other than the predetermined position, or if it is fixed with excessive force applied, there is another problem that the predetermined durability cannot be obtained, such as the transducer being easily broken. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention provides the following means: The toothbrush of the present invention is an ultrasonic toothbrush having at least a gripping part having a signal generating part that outputs a drive signal to be supplied to a vibrator that emits ultrasonic waves, a vibration part in which the vibrator is disposed, and a brush that is disposed in a position facing the vibration part and to which the ultrasonic waves emitted from the vibrator are supplied, wherein the vibration part has a space part, a maintaining means for maintaining the position of the vibrator inserted into the adhesive filled in the space until the adhesive hardens; and a flow path for air to be discharged when the vibrator is inserted into the space, The frequency of the drive signal is 3 MHz to 5 MHz.

[0008] Furthermore, the ultrasonic toothbrush of the present invention has An ultrasonic toothbrush having at least a gripping part having a signal generating part that outputs a drive signal to be supplied to a vibrator that emits ultrasonic waves, a vibration part in which the vibrator is arranged, and a brush that is arranged in a position facing the vibration part and to which the ultrasonic waves emitted from the vibrator are supplied, wherein the vibration part has a space part, and a maintaining means that maintains the position of the vibrator inserted into an adhesive filled in the space part until the adhesive hardens; The vibrator In the spaceEjected during insertion An air flow path is provided and a predetermined ultrasonic wave is output. It is characterized by the following.

[0009] Furthermore, the ultrasonic toothbrush of the present invention has The frequency of the ultrasonic waves is 3 MHz to 5 MHz. It is characterized by the following. [Effects of the Invention]

[0010] The present invention can provide an ultrasonic toothbrush that provides more effective brushing, for example, an improved cleaning effect such as plaque removal, by specifying the frequency of the ultrasonic waves used in the ultrasonic toothbrush.

[0011] Furthermore, even if the thickness of the vibrator used becomes thinner as the frequency used becomes higher, the vibrator can be mounted more reliably with an easy and simple structure, thereby avoiding damage to the vibrator when mounted and preventing a decrease in the yield rate, and providing a product that can maintain the desired performance for a long period of time. [Brief explanation of the drawings]

[0012] [Figure 1A] 1 is a left side view of an ultrasonic toothbrush according to the present invention. FIG. [Figure 1B] 1 is a front view of an ultrasonic toothbrush according to the present invention. [Figure 1C] FIG. 1 is a right side view of an ultrasonic toothbrush according to the present invention. [Figure 1D] FIG. 2 is a rear view of the ultrasonic toothbrush according to the present invention. [Figure 1E] 1 is a top view of an ultrasonic toothbrush according to the present invention. FIG. [Figure 1F] FIG. 2 is a bottom view of the ultrasonic toothbrush according to the present invention. [Figure 1G] 1 is a diagram showing a brush part of an ultrasonic toothbrush according to the present invention. FIG. [Figure 1H] 1 is a diagram showing the ultrasonic toothbrush according to the present invention in a state before the brush part is attached. FIG. [Figure 2] FIG. 2 is a block diagram of a controller of the ultrasonic toothbrush according to the present invention. [Figure 3] FIG. 2 is a schematic diagram of an ultrasonic drive signal according to the present invention. [Figure 4A] FIG. 1 is a diagram showing a vibrating section A19 (before vibrator 18 is arranged) of an ultrasonic toothbrush according to the present invention. [Figure 4B] FIG. 1 is a diagram showing a vibrating section A19 (after vibrator 18 is placed) of an ultrasonic toothbrush according to the present invention. [Figure 5A] FIG. 4B is a diagram showing a cross section taken along dashed line A in FIG. 4A. [Figure 5B] FIG. 4C is a diagram showing a cross section taken along dashed line B in FIG. 4B. [Figure 5C] 10A and 10B are diagrams showing modified examples of the path arrangement of the vibration section A19. [Figure 5D] 10A and 10B are diagrams showing modified examples of the path arrangement of the vibration section A19. [Figure 6A] FIG. 1 is a diagram showing a vibrating section B61 (before vibrator 18 is disposed) of an ultrasonic toothbrush according to the present invention. [Figure 6B] FIG. 10 is a diagram showing a vibrating section B61 (after vibrator 18 is placed) of the ultrasonic toothbrush according to the present invention. [Figure 6C] FIG. 2 is a diagram showing the arrangement of the vibrator 18. [Figure 6D] FIG. 6C is a diagram showing a cross section taken along dashed line C in FIG. 6B. [Figure 6E] 6C is a diagram showing a cross section taken along dashed line A in FIG. 4A when the configuration of the vibrator shown in FIG. 6C is used in FIG. 4A. [Figure 7A] FIG. 10 is a diagram showing a vibrating unit C71 of the ultrasonic toothbrush according to the present invention. [Figure 7B] 7B is a view seen from the direction of arrow A in FIG. 7A. [Figure 7C] FIG. 7C is a diagram showing a cross section taken along dashed line D in FIG. 7B. [Figure 7D] FIG. 7C is a diagram showing a cross section taken along dashed line D in FIG. 7B. [Figure 7E] FIG. 7C is a diagram showing a cross section taken along dashed line D in FIG. 7B. [Figure 7F] FIG. 7C is a diagram showing a cross section taken along dashed line D in FIG. 7B. [Figure 8A] FIG. 10 is a diagram showing a vibrating unit D83 of a conventional ultrasonic toothbrush. [Figure 8B] FIG. 10 is a diagram showing how a vibrator 8 is inserted into a vibrating part D83 of a conventional ultrasonic toothbrush. [Figure 8C] FIG. 10 is a diagram showing a state in which a vibrator 8 is inserted into a vibrating part D83 of a conventional ultrasonic toothbrush. [Figure 8D] FIG. 10 is a diagram showing a state in which a vibrator 8 is inserted into a vibrating part D83 of a conventional ultrasonic toothbrush. [Figure 9A] FIG. 10 is a diagram showing a vibrating unit E94 of the ultrasonic toothbrush according to the present invention. [Figure 9B] FIG. 2 is a diagram showing the configuration of a vibrator 18 and the like. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Embodiment 1) Figures 1A to 1H show the main body 1 of an ultrasonic toothbrush according to the present invention, showing six views of the main body 1. Figure 1A is a left side view, Figure 1B is a front view, Figure 1C is a right side view, Figure 1D is a rear view, Figure 1E is a top view, and Figure 1F is a bottom view. Figure 1G shows a brush unit 13 having a brush 14 at its tip, and Figure 1H shows the main body 1 before the brush unit 13 is attached. The main body 1 has a grip unit 11, an operating unit 15, a protruding portion 12 protruding from the tip of the grip unit 11, and a vibrating unit A19 at the tip of the protruding portion 12. The protruding portion 12 and the vibrating unit A19 may be configured as independent components or may be configured as an integrated unit. For example, a vibrating unit having a vibrator 18 that generates ultrasonic waves may be attached to the tip of the protruding portion 12. Alternatively, the protrusion may be elongated to the position where the brush 14 is placed when the brush part 13 is attached, and the vibrator 18 may be placed at the tip of the protrusion facing or corresponding to the brush 14, thereby forming a vibration part at the tip of the protrusion, i.e., the protrusion and the vibration part may be formed as a single unit.

[0014] A battery 16 and a controller 17 that controls the main body 1 in response to the operation of the operation unit 15 are provided inside the grip portion 11. The battery 16 and the controller 17, and the controller 17 and the vibrator 18 are connected by a harness A21 and a harness B20, respectively.

[0015] The operation unit 15 has a switch 22 and a red LED 23 disposed inside the switch 22. By pressing the switch 22 on the operation unit 15, the user can control the emitted ultrasonic waves, including whether to emit or stop the ultrasonic waves, and the lighting state of the LED 23 changes in response to the operation of the switch 22; for example, when the LED 23 lights up, the switch 22 lights up red, thereby informing the user of the drive state and operating state of the main body 1.

[0016] 2 is a block diagram of the controller 17. The controller 17 includes a signal generating unit 204 that outputs a drive signal, which is an electrical signal that is supplied to the transducer 18 to cause the transducer 18 to vibrate ultrasonically, a timer 207, a user IF unit 201, and a power supply unit that supplies predetermined power to each unit. 206, and includes at least a part or all of the control unit 202.

[0017] The control unit 202 incorporates a CPU, memory, and an interface unit for connecting with each unit, and controls the main body 1. The power supply unit 206 controls the power supplied from the battery 16 to a predetermined constant voltage value, for example, 5 V, and supplies it to each unit via the control unit 202. The user IF unit 201 is connected to the operation unit 15, and when the user operates the operation unit 15, it notifies the control unit 202 of that information.

[0018] Battery 16 may be a dry cell battery or a secondary battery that can be repeatedly used by recharging, such as a lithium-ion battery. Alternatively, instead of a battery, a power adapter that can output a predetermined voltage, for example, 5V, from a household outlet such as 100V may be used externally to main unit 1.

[0019] The timer 207 measures a predetermined time, for example, three minutes, as the time for brushing, that is, the time for driving the vibrator 18 to output ultrasonic waves. The time is not limited to three minutes, but may be less than three minutes or more than three minutes, and may be configured so that the user can set it as appropriate.

[0020] FIG. 3 is a schematic diagram of the output of the signal generating unit 204. In the diagram, the horizontal axis represents time and the vertical axis represents signal amplitude. The signal generating unit 204 outputs a signal with a frequency of, for example, 3.2 MHz or 4.8 MHz as a drive signal. In this embodiment, the drive signal is, for example, a 4.8 MHz sine wave output at time T1, followed by a 0.5-second pause at time T2, repeating this cycle. If T1 is set to 0.5 seconds and T2 to 0.5 seconds, the drive signal will output 4.8 MHz for 0.5 seconds, then pause for 0.5 seconds, and this cycle will be repeated. FIG. 3 shows the sine wave diagrammatically for ease of visualization, but in reality, the high frequency of 4.8 MHz is output at time T1, as described above.

[0021] In Figure 3, the drive signal is not output continuously, but is output at a 50% duty cycle as described above, or is output intermittently. While there is no significant difference in the ultrasonic effect between the constant output and the intermittent output shown in Figure 3, the actual drive time of the vibrator 18 per unit time is halved, which apparently extends battery life and increases the amount of time you can brush your teeth on a single charge. Here, the drive signal is output at 4.8 MHz intermittently with a 50% duty cycle, but the duty cycle is not limited to 50% and can be, for example, 40% or 60%, as long as the desired brushing effect is achieved.

[0022] When the user presses switch 22, the information is sent to control unit 202 via user IF unit 201, and control unit 202 instructs signal generation unit 204 to output an electrical signal as shown in Fig. 3. Alternatively, control unit 202 may be configured to supply power to signal generation unit 204, thereby causing signal generation unit 204 to start generating an electrical signal. Furthermore, control unit 202 notifies timer 207 to start measuring a predetermined time, for example, three minutes, and timer 207 starts measuring the predetermined time in accordance with the notification.

[0023] When a predetermined time, for example, three minutes, has elapsed, timer 207 notifies control unit 202 of this fact, and based on the notification, control unit 202 instructs signal generation unit 204 to stop signal output. Alternatively, control unit 202 stops the supply of power to signal generation unit 204, thereby causing signal generation unit 204 to stop generating a signal.

[0024] If the user presses the switch 22 again before the predetermined time has elapsed, the information is notified from the user IF unit 201 to the control unit 202, and the control unit 202 instructs the signal generating unit 204 to stop the signal output or stops the supply of power to the signal generating unit 204. At this time, the signal generation unit 204 stops generating signals, and at the same time, the timer 207 is instructed to stop measuring time, and the timer 207 is reset.

[0025] In the above-described operation of the switch 22 by the user, "pressing" the switch 22 does not necessarily mean simply pressing the switch 22. It may also mean pressing the switch 22 twice in a short time (a so-called double-click) or holding the switch 22 for several seconds (a so-called long-press). The operation method may be different for starting and stopping ultrasonic output, such as double-clicking to start output and long-pressing to stop signal output. In other words, it is preferable to change the operation method of the switch 22 depending on the purpose of operating the switch 22. This configuration is desirable because it can avoid malfunctions of the device caused by accidentally touching the switch 22. In particular, when the operation unit 15 is located on the grip unit 11, as in this embodiment, the user often touches the operation unit 15 unintentionally. Furthermore, because the user cannot recognize ultrasound waves, even if the ultrasound waves are unintentionally stopped when the switch 22 is accidentally pressed, the user may find it difficult to notice. This can lead to the user continuing to brush despite the ultrasound waves having stopped, resulting in a situation where the desired brushing effect is not achieved. Therefore, a double-click or long-press, which are difficult to achieve without the user's intention, is desirable as the operation of the switch 22 to stop ultrasound waves.

[0026] In this embodiment, the signal generating unit 204 outputs a 4.8 MHz drive signal as described above. The frequency of the ultrasound used was determined as follows: All subjects were trained in the correct brushing technique prior to the test, and individual differences in brushing were minimized by standardizing the brushing effect between subjects.

[0027] In addition to an ultrasonic toothbrush capable of using a 1.6 MHz frequency, three ultrasonic toothbrushes were also available: one capable of using a 3.2 MHz frequency and one capable of using a 4.8 MHz frequency. Group A brushed their teeth using the ultrasonic toothbrush that emitted only 1.6 MHz ultrasound, Group B brushed their teeth using the ultrasonic toothbrush that emitted only 3.2 MHz ultrasound, and Group C brushed their teeth using the ultrasonic toothbrush that emitted only 4.8 MHz ultrasound. Each group consisted of 17 and 16 subjects, respectively. However, the subjects in each group were not informed of the ultrasonic frequency emitted by the ultrasonic toothbrush they were using. Furthermore, because the frequencies used were in the ultrasonic range, none of the subjects were able to hear the sounds of the other frequencies, so they were unable to determine which frequency they were using. Subjects brushed their teeth for three minutes twice a day for eight consecutive weeks, and the study was conducted to determine which group achieved the greatest oral hygiene results.

[0028] The Plaque Index (hereinafter referred to as PlI) was used as an index to judge the effectiveness of brushing. A small PlI indicates less plaque. The Gingival Index (hereinafter referred to as GI) was also used as another index to show the effectiveness of brushing. A small GI indicates a low degree of gingivitis.

[0029] The PlI of Group A was 0.2-1.0 before the test and 0.0-0.75 after the test, in Group B it was 0.3-1.0 before the test and 0.0-0.5 after the test, and in Group C it was 0.3-1.2 before the test and 0.0-0.75 after the test, with the PlI values ​​decreasing at 3.2MHz and 4.8MHz compared to 1.6MHz.

[0030] The GI of Group A was 0.3-1.3 before the test and 0.35-1.5 after the test, for Group B it was 0.6-1.4 before the test and 0.15-1.2 after the test, and for Group C it was 0.45-1.7 before the test and 0.2-1.1 after the test, showing a tendency for the GI value to be lower at 3.2MHz and 4.8MHz than at 1.6MHz.

[0031] In other words, it can be seen that 3.2MHz and 4.8MHz provide a better brushing effect than 1.6MHz. However, the difference between 3.2MHz and 4.8MHz is greater than the difference between 1.6MHz, indicating that frequencies above 3.2MHz are more desirable for brushing than 1.6MHz.

[0032] As described above, by using an ultrasonic frequency of 3 MHz or higher, e.g., 3.2 MHz or 4.8 MHz, an ultrasonic toothbrush with a higher brushing effect can be realized. However, a higher ultrasonic frequency is not necessarily better. For example, if the frequency exceeds 5 MHz, the vibrator used will be very thin, making mass production of the vibrator difficult. This can also lead to cracks and breakage during the manufacturing process of the ultrasonic toothbrush, particularly when attaching the vibrator to the ultrasonic toothbrush—in this embodiment, when attaching it to the vibrating unit A19. Furthermore, if the main body 1 is dropped or otherwise subjected to a strong impact during use, the vibrator is likely to crack and break, preventing it from emitting the desired ultrasonic waves and resulting in frequent malfunctions. Therefore, vibrators that emit ultrasonic frequencies above 5 MHz are not suitable for mass production of the vibrators themselves, mass production of ultrasonic toothbrushes, or actual use of toothbrushes. Ultimately, frequencies between 3 MHz and 5 MHz are preferable, with 3.2 MHz to 4.8 MHz being the most desirable.

[0033] Furthermore, the present invention provides a method for mounting a vibrator on an ultrasonic toothbrush that has a simple configuration and does not reduce the yield rate or durability, even for vibrators that output frequencies of 3.2 MHz or 4.8 MHz, and the configuration of the ultrasonic toothbrush.

[0034] 4A and 4B show a schematic cross section of the vibration unit A19 of the main body 1. FIG. 4A shows the state of the vibration unit A19 before the vibrator 18 is placed therein. The vibration unit A19 has a space A41 in which the vibrator 18 is placed. As shown in FIG. 4B, the vibrator 18 is placed in the space A41, and when the brush unit 13 is attached, the brush 14 and the vibrator 18 face each other. That is, the vibrator 18 is placed at a position facing the brush 14. The vibrator 18 is fixed inside the space A41 at the tip of the vibration unit A19 by an adhesive layer A42 provided on the surface of the vibrator 18 facing the brush 14 (hereinafter referred to as the brush surface) and an adhesive layer B43 provided on the surface of the vibrator 18 on the back side of the brush surface (hereinafter referred to as the brush back surface). A harness B20 is connected to the vibrator 18, but is omitted from the drawing to avoid cluttering the illustration, and may be omitted hereinafter.

[0035] In this embodiment, the thickness of the vibrator 18 is, for example, about 450 μm. The thickness of the vibrator 18 varies depending on the frequency used. For example, when the frequency is 3.2 MHz, the thickness is about 650 μm, and when the frequency is 1.6 MHz, the thickness is about 1.3 mm. The thickness of the vibrator 18 not only varies easily depending on the frequency, but can also vary depending on the material and manufacturing method used. However, the tendency for the thickness to become thinner as the frequency increases is most pronounced and tends to be the dominant factor in the thickness of the vibrator.

[0036] If the thickness of the vibrator 18 is reduced, the strength of the vibrator 18 will decrease, and for example, the vibrator 18 will be more likely to break when it is attached to the space A41. The reason for this is as follows: When inserting the vibrator 18 into the space A41, adhesive is applied to the brush surface and the back surface of the vibrator 18, and before the adhesive hardens, the vibrator 18 is inserted into the space A41, for example, from the left side of the drawing in FIG. 4A, and pushed all the way into the space A41, allowing the adhesive to harden and fixing the vibrator 18 to the space A41. When the vibrator 18 is inserted into the space A41, it pushes in the air inside the space A41, which leaves no way for the air inside the space A41 to escape, and the air pushes back the vibrator 18, resulting in a large resistance when inserting the vibrator 18. Inserting the vibrator 18 against this resistance makes the work difficult, and it becomes necessary to apply even greater force to the vibrator 18 or to use a screw. Applying excessive load, such as bending the vibrator 18, can cause cracks, breakage, or fractures in the vibrator 18, which not only increases the defect rate but also makes it unable to output the specified ultrasonic waves, resulting in a defective product. Furthermore, vibrator 18 that is fixed under excessive load is more likely to be damaged, such as cracked, by the vibrations applied, for example, by dropping the main body 1, which shortens the life of vibrator 18 and reduces the durability of the product.

[0037] Furthermore, when the vibrator 18 is inserted into the space A41, the air in the space A41 has nowhere to go and pushes aside the adhesive, for example, it may be expelled by pushing aside the adhesive applied to the brush surface, preventing the formation of the desired adhesive layer A42. If the adhesive hardens in this state, voids, air layers, or bubbles will form in the adhesive layer A42, and even if the vibrator 18 emits a predetermined ultrasonic wave, the voids, air layers, or bubbles will prevent the predetermined ultrasonic wave from being transmitted to the brush portion 13, preventing the predetermined ultrasonic wave from being emitted from the brush 14, resulting in a problem in which the ultrasonic effect cannot be obtained.

[0038] Therefore, in this embodiment, by securing in advance a flow path for the air pushed out by the vibrator 18 when the vibrator 18 is inserted into the space A41, when the vibrator 18 is attached, the air in the space A41 is discharged by this flow path, and the vibrator 18 is smoothly inserted into the space A41 without being pushed back by the air. Therefore, no undue force is applied to the vibrator 18, and the vibrator 18 is not damaged when attached. The air flow path not only makes it easier to insert the vibrator 18 and increases the yield rate, but also allows the vibrator 18 to be fixed in the space A41 without applying an undue load to it, so that the specified ultrasonic waves can be output satisfactorily and there is no reduction in the product life, reliability, or durability.

[0039] Furthermore, the air discharged when the vibrator is inserted is discharged suitably from the air flow path, without affecting adhesive layer A42 or adhesive layer B43 in any way, and the desired positions of adhesive layer A42 or adhesive layer B43 can be easily formed. As a result, vibrator 18 can be correctly positioned and fixed, thereby providing an ultrasonic toothbrush that can transmit the specified ultrasonic waves to brush 14 and fully obtain the effects of the ultrasonic waves.

[0040] Figures 5A to 5D show cross sections of the vibrating section A19. Figure 5A is a cross section taken along dashed line A in Figure 4A, and Figure 5B is a cross section taken along dashed line B in Figure 4B, each showing a schematic cross section of the vibrating section A19 with the vibrator 18 disposed therein. In the space A41, flow paths A51 and B52, which serve as air flow paths, are provided on both sides of the vibrator 18. As shown in Figure 5B, neither the vibrator 18 nor an adhesive layer is disposed in these flow paths, and therefore, when the vibrator 18 is inserted into the space A41, the air filling the space A41 is discharged through these flow paths and does not impede the insertion of the vibrator 18.

[0041] When the vibrator 18 is inserted into the space A41, the air filled in the space A41 is discharged through these flow paths, so that the adhesive layers A42 and B43 provided on the brush surface and back surface are not pushed aside, and the adhesive layers A42 and B43 can be formed well.

[0042] The flow paths A51 and B52 allow the vibrator 18 to be easily inserted into the space A41 without applying an excessive load to the vibrator 18 when it is attached, and furthermore, the desired adhesive layer can be formed, which not only prevents a decrease in the yield rate but also allows the specified ultrasonic waves to be output and prevents product defects. Furthermore, the vibrator 18, which is fixed without applying an excessive load, is less likely to be damaged by the applied vibrations, and does not shorten the life of the vibrator 18, thereby not reducing the life, durability, or reliability of the product.

[0043] The flow path is preferably on both sides of the vibrator 18, which has the least effect on the oscillation of the vibrator 18, and is preferably on both sides of the vibrator 18 as shown in FIGS. 5A and 5B, or on the space A4. 1, i.e., on at least one of both sides of vibrator 18. However, as long as the desired vibration can be supplied to brush 14, flow path C53 may be arranged on the back surface of vibrator 18 on the brush rear surface side as shown in Fig. 5C, or flow path D54 may be provided as a through-hole at the very back of space A41 or at the tip of vibrating part A19 as shown in Fig. 5D. In this way, at least one air flow path may be arranged other than the irradiation surface, which is the surface of vibrator 18 that irradiates brush 14 with ultrasonic waves, in other words, other than the surface of the vibrator facing the brush, or at a position other than the area sandwiched between the vibrator and the brush.

[0044] Alternatively, multiple flow paths may be provided in a position other than the area sandwiched between the vibrator and the brush, and flow paths A51 and C53 may be provided, or flow paths B52 and C53 may be provided, or flow paths A51, B52, and C53 may be provided. In a configuration in which multiple flow paths are provided in this manner, even if adhesive unintentionally enters a flow path and blocks the flow path when inserting vibrator 18 into space A41, for example, even if flow path A51 is blocked, air can be discharged through another flow path, for example, flow path B52 or flow path C53, so that the installation of vibrator 18 is not hindered by air in space A41. In other words, a configuration in which multiple flow paths are provided is more desirable.

[0045] 5A to 5C, the flow path is configured so that its cross section is quadrangular, such as rectangular or square, or has corners. Even if adhesive unintentionally gets into the flow path when the transducer 18 is inserted into the space A41, the cross section of the flow path is less likely to be completely blocked, making it easier to maintain the flow path. Therefore, the cross section of the flow path only needs to have corners, and may be a cross section with, for example, a triangle or a polygon with five or more sides.

[0046] On the other hand, if the cross section of the flow path is, for example, a square, the manufacturing costs may be high. In this case, the cross section may be configured as a semicircle or a part of a circle, for example, an arch shape. However, if adhesive unintentionally gets into the flow path, the flow path is likely to become blocked, so it is better to provide multiple flow paths taking this into consideration.

[0047] 6A to 6E show vibrating part B61, which is another example of a vibrating part. A space B62 is provided in vibrating part B61, and a base A63 is formed in the space B62 by a step provided on the bottom surface of the space B62 as shown in the figure, which maintains the vibrator in a desired position. The vibrator 18 is disposed on the base A63. For example, adhesive layers A42 and B43 may be disposed on the surface of the vibrator 18 as in FIG. 4B, but in vibrating part B61, as shown in FIG. 6B, the adhesive layer B43 fixes a sponge layer, sponge 64, to the vibrator 18, and the vibrator 18 is disposed on the base A63 via the sponge 64.

[0048] The vibrator 18 is inserted into the space B62 while fixed to the sponge 64 as shown in Fig. 6C, and is then placed on the base A63 as shown in Fig. 6B. The vibrator 18 is fixed by the sponge 64 while being pressed against the top surface 66 of the space B62, which is the surface closest to the brush 14. In other words, the sponge 64 functions as a pressing means that presses the vibrator 18 against the top surface 66, which is the inner wall of the space B62, in the direction of the brush 14 when the brush part 13 is attached. Instead of the sponge 64, it is also possible to use an elastic material other than sponge, such as rubber or elastic resin, or a leaf spring.

[0049] The sponge 64, which is the pressing means, is very effective for forming a good adhesive layer A42 on the surface of the vibrator as in this embodiment. As described above, the vibrator 18 is inserted into the space A41 before the adhesive applied to the surface hardens. At this time, the adhesive on the surface of the vibrator 18 comes into contact with the upper surface 66 of the space A41 and is scraped off unevenly, forming unevenness in the adhesive layer A42 on the surface of the vibrator 18, which may result in an air layer being formed on the surface of the vibrator 18 as described above. In this case, defects occur due to the air layer, voids, or bubbles that are formed. However, since the vibrator 18 is pressed against the upper surface 66 by the pressing means as in the present embodiment, it is possible to make the adhesive that was temporarily uneven at the stage of inserting the vibrator 18 into a uniform, smooth layer, thereby making it possible to obtain a good adhesive layer A42.

[0050] The pressing means is very effective in forming a uniform adhesive layer A42, and can therefore be used for the vibrating part A19 shown in Fig. 4A, for example, or a sponge 64 may be fixed to the vibrator 18 and attached to the vibrating part A19 as shown in Fig. 6C. In this case, the cross section of the vibrating part A19 will be as shown in Fig. 6E.

[0051] FIG. 6D is a schematic cross-sectional view taken along dashed line C in FIG. 6B, showing another example of a flow path. As shown in the figure, a flow path different from the above is formed by narrowing the width of the sponge 64, adhesive layer A42, adhesive layer B43, base A63, etc., compared to the width of the vibrator 18. That is, by narrowing the width of the adhesive layer or pressing means in a direction different from the insertion direction of the vibrator into the space, e.g., perpendicular to the insertion direction, compared to the vibrator, an air flow path is formed by the gap formed between the adhesive layer and the pressing means and the side of the space. While multiple flow paths can be created by narrowing the width of each adhesive layer and sponge as shown in the figure, a flow path can also be formed by narrowing only a portion of the layer or base provided on the brush front or back side of the vibrator 18 while leaving the widths of the other layers unchanged. For example, a flow path can be formed by narrowing only the adhesive layer A42, only the adhesive layer B43 on the back side of the brush, or only the sponge 64, or only the base A63, or by using only a portion of these. For example, various configurations are possible, such as forming a flow path by reducing only the width of adhesive layer B43 and sponge 64, or by reducing the width of adhesive layer A42 and adhesive layer B43, or by reducing the width of adhesive layer A42 and sponge 64. Note that in Fig. 6E, the width of adhesive layer A42 and sponge 64 is set to be equal to that of vibrator 18, but this is not limiting, and a configuration in which an air flow path is formed by reducing the width of at least one of adhesive layer A42, adhesive layer B43, or sponge 64 less than the width of vibrator 18, as shown in Fig. 6D, is also possible.

[0052] In the above, adhesive layer A42 and adhesive layer B43 may be layers of a curable flow agent as long as they can reliably fix vibrator 18 to space portion A41, sponge 64, etc. Therefore, in addition to adhesive, thermosetting resin, thermoplastic resin, or other curable resin, etc., can be used, such as epoxy resin, rubber, or adhesives based on these. Note that in Figures 6A to 6E, since adhesive layer B43 fixes vibrator 18 and sponge 64, double-sided tape, etc., can be used instead of adhesive layer B43, and the flow path as described above can be formed by making the width of the double-sided tape used narrower than the width of vibrator 18.

[0053] In the configurations of Figures 6A to 6E, the flow path is formed by adjusting the width of the layer used to fix the vibrator 18, but this is not limited to this, and a configuration in which the flow path is arranged on the side of the vibrator 18 as in Figures 5A to 5D is also possible, or as in Figures 6A to 6E, a flow path may be formed by reducing the width of the layer or member used to fix the vibrator 18, and at the same time, at least one of flow path A51, flow path B52, or flow path C53 may be provided on the side of space B62 on both sides of the vibrator 18, or on the surface of space B62 facing the back surface of the brush of the vibrator 18.

[0054] Figures 7A to 7F show other examples of the configuration of the vibration unit. Figures 7A to 7F show schematic cross sections of vibration unit C71 in which vibrator 18 is arranged. Figure 7A shows the state before vibrator 18 is arranged in vibration unit C71. A space C72 is provided inside vibration unit C71, with the left side as you face the drawing being the grip unit 11, and the brush 14 being arranged at the right end, i.e., the distal end relative to grip unit 11, when brush unit 13 is attached. An opening A73 is provided at the distal end of space C72, into which vibrator 18 can be inserted.

[0055] Fig. 8A shows the configuration of a conventional vibrating unit D83 of a toothbrush having an opening B81 at the tip. To attach vibrator 18 to a configuration like that of Fig. 8A, a curable resin, for example, adhesive 82, is filled through opening B81 as shown in Fig. 8B. Note that adhesive 82 is filled in a state in which harness B20 has been inserted into the interior through opening B81 in advance. Subsequently, vibrator 18 is inserted through opening B81, or harness B20 that has already been inserted is pulled, and vibrator 18 is drawn in through opening B81, and when adhesive 82 hardens in this state, vibrator 18 is fixed. While such a configuration allows for vibrator placement with a simple configuration, it has the following problems.

[0056] With the configuration shown in FIG. 8A , it is difficult to insert the transducer 18 correctly. For example, it is easy to insert the transducer 18 closer to the brush 14 than the intended position, or farther away from the brush 14, or insert it too deeply or too shallowly, or it may be displaced in a direction perpendicular to the insertion direction (toward or away from the paper), or it may be tilted relative to the brush 14. FIGS. 8C and 8D show examples of these situations, with FIG. 8C showing a case where the transducer 18 is inserted too deeply, and FIG. 8D showing a state where the transducer 18 is tilted. Even if the transducer 18 is inserted correctly, it may move before the adhesive 82 hardens, making it difficult to maintain or position the transducer 18 in the intended position as shown in FIG. 8C or 8D. This can result in ultrasonic waves not being properly supplied to the brush 14.

[0057] In contrast, the following configuration is used in Figures 7A to 7F to solve the problem of inserting the transducer 18 through an opening provided at the tip. Figure 7B shows a view from the direction of arrow A in Figure 7A, and Figure 7C shows a cross-sectional view taken along dashed line D in Figure 7B. As shown, opening A73 is provided with insertion paths A74 and B75 through which the transducer 18 is inserted as a means for maintaining the transducer position. Insertion paths A74 and B75 are provided on the side of space C72 along the direction of transducer 18 insertion to position the transducer 18 at a predetermined location, for example, to face the brush 14 when the brush unit 13 is attached. The width from the side of insertion path A74 to the side of insertion path B75 is the same as or slightly larger than the width of the transducer 18, and the transducer 18 is inserted into this space and maintained at the predetermined position. The method of inserting the transducer 18 is substantially the same as that shown in Figures 8A to 8D. First, the harness B20 is inserted into the space C72 from the opening A73, and with the vibrator 18 outside the space C72, adhesive 82 is filled into the space C72 as shown in FIG. 7D. In FIGS. 7A to 7F, a protrusion 76 is provided to prevent the filled adhesive 82 from leaking out, thereby minimizing the leakage of the adhesive 82. A gap 77 through which the harness B20 passes is provided above the protrusion 76, and the harness B20 passes through this gap to connect to the controller 17 inside the gripping part 11. The vibrator 18 is pulled in by pushing the vibrator 18 from the opening A73 along the insertion path A74 and the insertion path B75, or by pulling the harness B20, so that the vibrator 18 can be reliably moved to a predetermined position along the insertion path A74 and the insertion path B75.

[0058] Insertion of the vibrator 18 allows some of the adhesive 82 to flow through the gap 77, preventing or reducing overflow of the adhesive from the opening A73 and preventing or reducing adhesion of the adhesive 82 to the outer periphery of the vibrating portion C71. After insertion of the vibrator 18, the adhesive 82 solidifies, fixing the vibrator 18 in the desired position. Since the movement of the vibrator 18 leaves a portion of the opening A73 without adhesive 82, as shown in FIG. 7E, the opening A73 may be blocked by replenishing this portion with adhesive 82, as shown in FIG. 7F. This configuration allows the vibrator 18 to be inserted correctly, reliably, and easily into the desired position. Furthermore, the desired position of the vibrator 18 is reliably maintained until the adhesive 82 solidifies. This prevents problems when attaching the vibrator 18 and improves the yield rate.

[0059] 9A and 9B show other examples of the maintaining means. A base portion B91 is formed as a support means on the bottom surface of the space D93 where the vibrator 18 is placed. FIG. 9B shows a configuration in which the support means is provided on the vibrator 18 rather than on the vibrating portion or the space, with a base portion C92 provided on the vibrator 18. The base portion C92 is fixed to the vibrator 18 with an adhesive layer B43, but it may also be fixed with double-sided tape. The base portion C92 may be made of an elastic material such as rubber or sponge, or a non-elastic material such as resin. The base portion B91 is formed by a step provided in the space D93, and the base portion C92 is a rectangular parallelepiped member. However, the shape of the support means is not limited to this and may be a multi-projection shape, a plate shape, a dome shape, or a sickle-shaped shape, as long as it can properly support the vibrator. In these cases, as in FIG. 7, adhesive 82 is first filled in, followed by inserting the vibrator 18 and allowing the adhesive 82 to harden, thereby fixing the vibrator 18. It is desirable to provide protrusions 76 and gaps 77 as in FIGS. 7A to 7F also in FIGS. 9A and 9B.

[0060] With the above configuration, an ultrasonic toothbrush can be provided that can be easily installed in a predetermined position without damaging the vibrator 18, even when using a high-frequency vibrator, and the defect rate does not increase even when the ultrasonic frequency becomes high.Furthermore, an ultrasonic toothbrush that is resistant to externally applied vibrations and highly reliable can be provided. The toothbrush of the present invention is an ultrasonic toothbrush having at least a grip portion having a signal generating unit that outputs a drive signal to be supplied to a vibrator, a protrusion provided at the end of the grip portion, a vibration portion at the tip of the protrusion in which the vibrator is arranged, and a brush positioned opposite the vibration portion, and is characterized in that the frequency of the drive signal is 3 MHz to 5 MHz. Furthermore, the ultrasonic toothbrush of the present invention is characterized by having a flow path for discharging air at the position where the vibrator is placed when the vibrator is placed in the space inside the vibration unit. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the flow path is provided on at least one of both side surfaces of the vibrator. The toothbrush of the present invention is an ultrasonic toothbrush having at least a grip portion having a signal generating unit that outputs a drive signal to be supplied to a vibrator, a protrusion provided at the end of the grip portion, a vibration portion in which the vibrator is arranged at the tip of the protrusion, and a brush that is arranged opposite the vibration portion and to which the ultrasonic waves emitted from the vibrator are supplied, wherein the vibration portion has a space portion, and a maintaining means is provided for maintaining the position of the vibrator inserted into adhesive filled in the space portion, and the frequency of the drive signal is 3 MHz to 5 MHz. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the means for maintaining the position of the vibrator is an insertion path through which the vibrator is inserted into the adhesive filled in the space. The ultrasonic toothbrush of the present invention is an ultrasonic toothbrush having at least a gripping portion having a signal generating unit that outputs a drive signal to be supplied to a vibrator that emits ultrasonic waves, a vibration portion in which the vibrator is disposed, and a brush that is disposed opposite the vibration portion and to which the ultrasonic waves emitted from the vibrator are supplied, wherein the vibration portion has a space portion, and a maintaining means is provided for maintaining the position of the vibrator inserted into adhesive filled in the space portion until the adhesive solidifies, and the frequency of the drive signal is 3 MHz to 5 MHz. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the means for maintaining the position of the vibrator until the adhesive hardens is an insertion path in which the vibrator is inserted into the adhesive filled in the space, and which is provided on both sides of the space to reliably move the vibrator to a predetermined position. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the width of the retaining means, in the direction perpendicular to the direction in which the vibrator is inserted into the space, is made narrower than the width of the vibrator, so that a gap is formed between the side of the space and the retaining means, forming a flow path for air to be discharged when the vibrator is inserted into the space. Furthermore, the toothbrush of the present invention is an ultrasonic toothbrush having at least a gripping section having a signal generating section that outputs a drive signal to be supplied to a vibrator that emits ultrasonic waves, a vibration section in which the vibrator is disposed, and a brush that is disposed opposite the vibration section and to which the ultrasonic waves emitted from the vibrator are supplied, wherein the vibration section has a space, the space has the vibrator inserted in adhesive that is filled in the space, and a base section that has a pressing means for placing the vibrator, and the pressing means presses the vibrator in a direction approaching the brush, and the frequency of the drive signal is 3 MHz to 5 MHz. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the space has a flow path through which air is discharged, and the cross section of the flow path has a corner. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the flow path is provided as a through-hole at the tip of the vibration part.

[0061] This international application claims priority based on Japanese Patent Application No. 2019-002982, filed on January 10, 2019, and the entire contents of Japanese Patent Application No. 2019-002982 are incorporated herein by reference. [Explanation of symbols]

[0062] 1 Main unit 11 Gripping part 12 Protrusion 13 Brush section 14 Brushes 15 Control section 16 Battery 17 Controller 18 oscillators 19 Vibration section A 20 Harness B 21 Harness A 22 Switch 23 LED 41 Space A 42 Adhesive layer A 43 Adhesive layer B 51 Flow path A 52 Flow path B 53 Flow path C 54 Flow path D 61 Vibration part B 62 Space B 63 Base A 64 Sponge 66 Top surface 71 Vibration part C 72 Space C 73 Opening A 74 Insertion Path A 75 Insertion Path B 76 Protrusion 77 void 81 Opening B 82 Adhesive 83 Vibration part D 91 Base B 92 Base C 93 Space D 94 Vibration part E 201 User IF Department 202 Control section 204 Signal Generation Unit 206 Power supply section 207 Timer

Claims

1. a gripping unit having a signal generating unit that outputs a drive signal to be supplied to a transducer that emits ultrasonic waves; a vibration section in which the vibrator is disposed; a brush that is disposed in a position facing the vibration unit and to which the ultrasonic waves emitted from the vibrator are supplied, The vibration section has a space section, a maintaining means for maintaining the position of the vibrator inserted in the adhesive filled in the space until the adhesive hardens; a flow path for air to be discharged when the vibrator is inserted into the space portion is provided; An ultrasonic toothbrush, wherein the frequency of the drive signal is between 3 MHz and 5 MHz.

2. A gripping unit having a signal generating unit that outputs a drive signal to be supplied to a vibrator that emits ultrasonic waves; a vibration section in which the vibrator is disposed; a brush that is disposed in a position facing the vibration unit and to which the ultrasonic waves emitted from the vibrator are supplied, The vibration section has a space section, a maintaining means for maintaining the position of the vibrator inserted in the adhesive filled in the space until the adhesive hardens; a flow path for air to be discharged when the vibrator is inserted into the space portion is provided; An ultrasonic toothbrush that outputs a predetermined ultrasonic wave.

3. An ultrasonic toothbrush as described in claim 2, characterized in that the frequency of the ultrasonic waves is 3 MHz to 5 MHz.

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