ultrasonic toothbrush

Abstract

To provide an ultrasonic toothbrush capable of reliably supplying ultrasonic waves emitted from a vibration part to a tooth surface via a brush and exerting favorable brushing effects for a prolonged period.SOLUTION: Following means is devised for solving the problem. A toothbrush is an ultrasonic toothbrush including a grip part, a protrusion part protruding from a tip end of the grip part, a vibration part formed at a tip of the protrusion part and including a transducer for generating ultrasonic waves, arranged thereon, and a bristle-bearing part filled with a plurality of bristle bundles to form a brush. The bristle-bearing part is arranged, with a cavity interposed toward the vibration part, and has an opening part leading to the cavity.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Electric toothbrushes have been put to practical use, which vibrate the brush during brushing to improve brushing effectiveness, including plaque removal and cleaning (hereinafter simply referred to as "brushing effectiveness"). Furthermore, ultrasonic toothbrushes that use ultrasound to improve brushing efficiency and achieve good tooth brushing have been proposed, for example, as described in Patent Documents 1 to 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, if the bristles become bent, broken, or worn down with use, the brush head needs to be replaced. Therefore, a design that allows only the brush head to be replaced is desirable.

[0005] In toothbrushes that use ultrasonic waves, if a gap occurs between the vibrating part where the ultrasonic vibrator is located and the bristle part, the ultrasonic waves emitted from the vibrating part cannot be transmitted to the brush and cannot be delivered to the surface of the teeth, resulting in the full effect of the ultrasonic waves and insufficient brushing effectiveness.

[0006] However, it is extremely difficult to create a structure that allows the brush part to be replaced without creating any gaps or air gaps (hereinafter simply referred to as "air gaps") between the vibration part and the brush part. Even if the brush part is not replaceable, extremely high dimensional precision is required for both the vibration part and the brush part to prevent even partial gaps between them. For these reasons, there is a demand for an ultrasonic toothbrush that can reliably deliver ultrasonic waves emitted from the vibration part to the tooth surface via the brush, and that can provide good brushing effects over a long period of time. [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 comprises a grip portion, a protruding portion protruding from the tip of the grip portion, a vibration portion formed at the tip of the protruding portion and having a vibrator that generates ultrasonic waves, a bristle portion in which a plurality of bristle bundles are planted to form a brush, and a brush part in which the bristle part is disposed on a first surface and the vibration part is inserted through a first opening to be detachable; a gap provided between the vibration part and the bristle part; a second opening different from the first opening and communicating with the gap on the first surface; and a third opening different from the first opening and different from the second opening on a second surface of the brush part different from the first surface, the third opening being communicating with the gap. It is characterized by having an opening.

[0008] Furthermore, the ultrasonic toothbrush of the present invention has The brush portion has a flow path that connects the gap and the third opening. It is characterized by the following. [Effects of the Invention]

[0009] The present invention provides an ultrasonic toothbrush that can supply ultrasonic waves to the tip of the toothbrush to achieve good brushing effects. Furthermore, it can realize a highly reliable ultrasonic toothbrush that can maintain brushing effects for a long period of time with a simpler configuration. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram of an ultrasonic toothbrush according to the present invention. [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 4]1 is an explanatory diagram of an ultrasonic toothbrush according to the present invention. [Figure 5] FIG. 1 is an explanatory diagram of a conventional ultrasonic toothbrush. [Figure 6] 1 is an explanatory diagram of an ultrasonic toothbrush according to the present invention. [Figure 7] 1 is an explanatory diagram of an ultrasonic toothbrush according to the present invention. [Figure 8] 1 is an explanatory diagram of a charger for an ultrasonic toothbrush according to the present invention. [Figure 9] FIG. 1 is a block diagram of a charging circuit for an ultrasonic toothbrush according to the present invention. [Figure 10] 3 is a flowchart of charging control of the ultrasonic toothbrush according to the present invention. [Figure 11] FIG. 1 is a block diagram of a charging circuit for an ultrasonic toothbrush according to the present invention. [Figure 12] 3 is a flowchart of charging control of the ultrasonic toothbrush according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] FIG. 1 shows the main body 1 of an ultrasonic toothbrush according to the present invention, with (a) to (f) showing six views of the main body 1. (a) is a left side view, (b) is a front view, (c) is a right side view, (d) is a rear view, (e) is a top view, and (f) is a bottom view. (g) shows the main body 1 before the brush unit 13 is attached, and the brush unit 13 has a handle 11, an operating unit 15, and a protrusion 12 protruding from the tip of the handle 11. The main body 1 has a vibration unit 19 formed at the tip of the protrusion 12 and equipped with a vibrator 18 that generates ultrasonic waves. The protrusion 12 and the vibration unit 19 may be configured as independent components or may be configured as an integrated unit. For example, the vibration unit 19 having the vibrator 18 that generates ultrasonic waves may be attached to the tip of the protrusion 12. Alternatively, the protrusion 12 may be elongated to the position where the brush 14 is placed when the brush part 13 is attached, and a vibrator 18 may be placed at the tip of the protrusion 12 facing or corresponding to the brush 14, thereby forming a vibration part 19 at the tip of the protrusion 12, i.e., the protrusion 12 and the vibration part 19 may be formed as a single unit.

[0012] 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 controller 17 and the vibrator 18 are connected by a harness-B20 as will be described later.

[0013] The operation unit 15 has a switch 22, and an LED unit 23 that lights up red using a built-in red LED is arranged around the switch 22. By pressing the switch 22 on the operation unit 15, the user can control the ultrasound waves to be emitted, including whether to emit or stop the ultrasound waves, and the lighting state of the LED unit 23 changes depending on the operation of the switch 22; for example, when the LED unit 23 lights up, the area around the switch 22 lights up red, informing the user of the drive state and operating state of the main body 1.

[0014] 2 is a block diagram of the controller 17. The controller 17 includes at least some or all of a signal generating unit 204 that outputs a drive signal, which is an electrical signal that is supplied to the vibrator 18 to cause the vibrator 18 to vibrate ultrasonically, a timer 207, a user IF unit 201, a power supply unit 206 that supplies predetermined power to each unit, a control unit 202, etc.

[0015] The control unit 202 incorporates a CPU, memory, and an interface 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.

[0016] 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 these batteries, a power adapter that can output a predetermined voltage, for example, 5V, from a household outlet, such as a 100V outlet, may be installed outside main unit 1. However, secondary batteries may be preferable from the perspective of environmental impact, and this embodiment uses a secondary battery, such as a lithium-ion battery, as an example.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] When the user presses switch 22, this 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 this notification.

[0021] 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.

[0022] If the user presses switch 22 again before the predetermined time has elapsed, that information is notified from user IF unit 201 to control unit 202, and control unit 202 instructs signal generation unit 204 to stop signal output or stops the supply of power to signal generation unit 204, thereby stopping signal generation by signal generation unit 204. At the same time, it instructs timer 207 to stop measuring time, and resets timer 207.

[0023] 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, it is difficult for the user to notice that the ultrasound waves have been unintentionally stopped when the switch 22 is accidentally pressed. This can lead to a situation where the user continues brushing even though the ultrasound waves have stopped, resulting in a failure to achieve the desired brushing effect. 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.

[0024] Figure 4 shows a brush unit 13 to which the present invention is applied. Figure 4(a) is an enlarged view of the brush unit 13, and Figure 4(b) is a schematic cross-sectional view taken along dashed line A in Figure 4(a). In this embodiment, the brush unit 13 has a brush 14 formed by implanting a plurality of bristle bundles 45 in a bristle implantation portion 43. An opening-A41 is provided in the bristle implantation portion 43 at its rear end, in other words, at the proximal end thereof.

[0025] 4(c) shows a cross section of the vibration unit 19 inserted into the brush unit 13. At the tip of the vibration unit 19, a vibrator 18 is fixed with adhesive 82 in a portion that corresponds to the brush 14 when the vibration unit 19 is inserted into the brush unit 13. The vibrator 18 is connected to a controller 17 disposed in the grip unit 11 by a harness-B20, and a drive signal is supplied to the controller 17. The vibrator 18 may be disposed inside the vibration unit 19 as shown in FIG. 4(c), but may also be disposed on the surface of the vibration unit 19, for example, on the surface of the vibration unit 19 facing the brush 14, or on the opposite side of the surface facing the brush 14.

[0026] Figure 4(d) shows the state in which the vibration unit 19 of Figure 4(c) is inserted into the insertion portion 44 of the brush unit 13 of Figure 4(b), and in this state the toothbrush body 1 is used for brushing. As shown in the figure, a gap-A42 is formed between the vibration unit 19 and the brush 14. An opening-A41 passes through the bristle portion 43 and connects to the gap-A42. When a user uses the body 1, toothpaste, saliva, or moisture such as water containing these (hereinafter collectively referred to as moisture) enters the gap-A42 through the opening-A41.

[0027] As shown in Figure 4, by configuring the brush head 13 and the vibration head 19 to be detachable, the brush head 13 can be made replaceable. Note that when the brush head 13 and the vibration head 19 are made replaceable, this detachable configuration is an essential configuration, as will be described later, but is not necessarily essential in cases where, for example, the ultrasonic toothbrush is disposable, there is no need to replace the brush head 13. However, the openings-A41 and the gaps-A42 are essential to ensure that ultrasonic waves are supplied to the teeth.

[0028] In toothbrushes that use ultrasonic waves, a part corresponding to the vibration part 19 in FIG. 4 is typically inserted into the brush part 13 to facilitate easy replacement. For example, the configuration described in the aforementioned patent document can be illustrated as shown in FIG. 5. In this embodiment, the vibration part 19 is designed to be in close contact with the surface that faces the brush 14 (i.e., the ultrasonic wave emitting surface) and the bristle part 43 where the brush 14 is attached, so that no gap is created, even if only partially. If a gap is created, the ultrasonic waves emitted from the vibrator 18 cannot pass through the gap, preventing the ultrasonic waves from reaching the brush 14 or the tooth surface, resulting in an inability to achieve the desired brushing effect. To prevent this, the dimensions of the part of the replacement brush part 13 into which the vibration part 19 is inserted must be precisely matched to the dimensions of the vibration part 19 to be inserted. However, due to variations in mass production and changes over time, it is impossible to precisely match the dimensions of the two, and there is a high possibility that a partial gap may be created unintentionally. Furthermore, even if accurate dimensions were initially used to prevent such gaps, gaps may develop over time due to twisting or other factors during use. Also, gaps are likely to develop if the device is dropped, hit against something, or subjected to strong vibrations. When gaps develop, ultrasonic waves cannot be delivered to the tooth surface via the brush 14, as described above, and the desired brushing effect cannot be achieved.

[0029] On the other hand, in the ultrasonic toothbrush of the present invention, as shown in Figure 4, the bristle part 43 of the brush 14 has an opening-A41, which communicates with the gap-A42 formed between the vibrating part 19 and the bristle part 43. When moisture flows into the opening-A41, the gap-A42 is filled with moisture. Even though there is a gap-A42, the ultrasonic waves emitted from the vibrating part 19 reach the bristle part 43 due to the moisture that has filled the gap-A42, and are supplied to the tooth surface via the brush 14, thereby achieving the desired brushing effect. The filled moisture is discharged when the brush part 13 is washed after brushing is finished.

[0030] In such a configuration, the dimensional accuracy of the vibration unit 19 and the insertion unit 44 into which the vibration unit 19 is inserted is sufficient as long as the vibration unit 19 is inserted into the insertion unit 44 and the brush unit 13 is securely attached to the main body 1, so high accuracy is not required and an inexpensive configuration is possible.

[0031] Furthermore, even if changes occur over time in the vibration part 19 or brush part 13 during use, or if strong vibrations are applied, such as when the device is dropped, the ultrasonic waves emitted from the vibration part 19 are reliably supplied to the surface of the teeth being brushed via the moisture that has flowed into the gap-A42 and the brush 14, thereby achieving the desired brushing effect.

[0032] In other words, by intentionally providing a gap-A42 between the vibrating part 19 and the bristle part 43, which has traditionally been designed to prevent gaps, and filling this gap with moisture generated during brushing through the opening-A41, an ultrasonic toothbrush can be realized that has a simpler structure, is resistant to vibrations and changes over time regardless of high dimensional accuracy, can reliably supply ultrasonic waves to the surface of the teeth via the brush 14, and provides good brushing effects over a long period of time.

[0033] Therefore, the present invention makes it possible to realize a highly reliable ultrasonic toothbrush that does not impair the desired brushing effect over a long period of time, with an inexpensive replacement brush configuration that does not require high dimensional accuracy.Furthermore, even if replacement is not required, a highly reliable ultrasonic toothbrush that does not impair the desired brushing effect over a long period of time, with an inexpensive configuration that does not require high dimensional accuracy, can be realized.

[0034] [Example of change] FIG. 6 shows another example of an opening according to the present invention. In FIG. 4, opening-A41 is located at the rear end of the bristle portion 43, while in FIG. 6(a), opening-B61 is located at the tip of the bristle portion 43. In FIG. 6(b), opening-C62 is located between the brushes 14. Alternatively, openings may be located on the right or left side of the brush 14 in the axial direction (the direction in which the protruding portion 12 protrudes from the main body 1), such as the right or rear end or the left or front or rear end. Alternatively, these openings may be located at positions corresponding to the side surface, distal end, or proximal end of the gap-A42. For example, FIG. 6(d) shows an example in which opening-H60 is located at the distal end of the gap-A42 or at the tip of the brush portion 13.

[0035] Although the above description cites an example in which the bristle portion 43 and the brush portion 13 each have one opening, the present invention is not limited to this configuration and may have two or more openings. That is, if opening-A41 is defined as the first opening, a second opening may be provided separately from the first opening. In this case, the openings may have the same size and shape, or may have different shapes and sizes. Note that providing a first opening and a second opening does not necessarily mean that there are only two openings, but may also mean that two or more openings are provided. When a first opening and a second opening are provided, moisture in gap-A42 is more easily expelled than when a second opening is not provided. However, since there is an abundance of moisture in the oral cavity during brushing, the moisture is quickly replenished in gap-A42, and ultrasonic waves are transmitted to the brush 14, preventing a decrease in brushing effectiveness.

[0036] While opening-A41 in Fig. 4(d), opening-B61 in Fig. 6(a), and Fig. 6(d) are located at the end of gap-A42, Fig. 6(c) shows opening-D63 located away from the end of gap-A42. In this case, a pocket 64 surrounded on three sides by the vibration unit 19 and the bristle unit 43, etc., is formed at the end of gap-A42 in Fig. 6(c). This makes it easy for moisture to accumulate in this pocket 64. When brushing is finished and the brush 14 is washed, draining the moisture that has filled gap-A42 can be difficult or insufficient. If drainage is difficult, the moisture in gap-A42 tends to remain in gap-A42, which is unhygienic.

[0037] Therefore, in the present invention, it is desirable to position openings such as openings-A41, openings-B61, and openings-H-60 at the ends of the gap. Positioning openings at the ends prevents pockets 64, allowing moisture to be efficiently discharged from inside gap-A42, resulting in a hygienic ultrasonic toothbrush that provides excellent brushing results over a long period of time. Here, the "end" does not necessarily refer to the end of gap-A42 corresponding to the front or rear end of bristle portion 43 as shown in Figures 4 and 6, but may also refer to the end of gap-A42 corresponding to the right or left side of brush 14 in the axial direction.

[0038] Regardless of the presence or absence of the pocket 64, if the size or shape of the openings such as openings-A41 to openings-H60 (simply referred to as openings) makes it difficult to drain moisture from the gap-A42, multiple openings may be provided. For example, two or more openings-A41 may be provided, or two or more openings-B61 may be provided. Alternatively, the above-mentioned openings such as openings-A41 and openings-B61 may be used in combination. In this case, the multiple openings may be adjacent to each other, or may be spaced apart, such as at the front and rear ends of the bristle-implanted portion 43 or on the right and left sides of the bristle-implanted portion 43. Alternatively, three or more openings may be provided in three or more regions, such as at the front and rear ends of the bristle-implanted portion 43 and on the right and left sides.

[0039] If the surface of the brush unit 13 on which the bristle unit 43 is arranged is referred to as the front surface of the brush unit 13 or the first surface of the brush unit 13, and the surface opposite the front surface of the brush unit 13 (the first surface of the brush unit 13) is referred to as the back surface of the brush unit 13 or the second surface of the brush unit 13, then one of the openings may be arranged on the first surface of the brush unit 13 or the front surface of the brush unit 13, and the other opening may be arranged on the second surface of the brush unit 13 or the back surface of the brush unit 13, as shown in Figure 7. In Figure 7(a), in addition to opening-A41, opening-E65 is also provided on the opposite side of the vibrating unit 19 from the brush 14. In other words, opening-A41, which is the first opening, is provided on the front surface of the brush unit 13, and opening-E65, which is the second opening, is provided on the second surface of the brush unit 13 or the back surface of the brush unit 13. In other words, the first opening is provided on the surface of the brush unit 13 where the bristle unit 43 is arranged, and the second opening is provided on the opposite side of the vibration unit 19 with respect to the bristle unit 43 and the brush 14. Alternatively, opening-A41 and opening-E65 are arranged so that the vibration unit 19 is disposed between them. Figures 7(b) and 7(c) also show examples in which opening-A41 and opening-F67 or opening-G68 are arranged to sandwich the vibration unit 19 or on the front and back surfaces of the brush unit 13. Figure 7(a) shows opening-E65 provided at the tip of the back surface of the brush unit 13 (opposite the brush 14), Figure 7(b) shows opening-F67 provided on the back surface of the brush unit 13 at a position corresponding to the center of the brush 14, and Figure 7(c) shows opening-G68 arranged on the back surface of the brush unit 13 at a position corresponding to the rear end of the brush 14.

[0040] Furthermore, in Fig. 7(a), a flow path-A66 is provided connecting gap-A42 and opening-E65, i.e., a flow path-A66 is provided connecting gap-A42 formed between vibration unit 19 and brush unit 13 to the second opening, and moisture present in gap-A42 is easily discharged from opening-E65 by flow path-A66. Fig. 7(d) shows a schematic cross section taken along dashed line B in Fig. 7(b). Fig. 7(d) shows an example in which flow path-B69 connecting gap-A42 to opening-F67 is provided on both sides of vibration unit 19, but flow path-B69 may be provided on at least one side of vibration unit 19, i.e., on at least one of the right and left sides of vibrator 18 in Fig. 7(d).

[0041] Figure 7(e) is a schematic cross-section taken along dashed line C in Figure 7(b). In Figure 7(e), flow path-B69 is located at the position of opening-F67 through a recess or groove in the brush unit 13. Figure 7(f) shows another example of a flow path. Flow path-C70 is provided instead of flow path-B69 in Figure 7(e). Flow path-C70 is located at the tip of the vibration unit 19 and extends along the longitudinal direction of the vibration unit 19. As shown in Figure 7(f), flow path-C70 may have a length equal to the longitudinal length of gap-A42, which is desirable because it prevents the formation of a pocket like pocket 64. For flow paths-A66 and flow path-B69, the longitudinal angle of the brush unit 13 must be appropriately adjusted to allow moisture to flow toward the second opening. However, flow path-C70 is more desirable because it allows moisture to be smoothly discharged from gap-A42 regardless of the longitudinal angle of the brush unit 13.

[0042] FIG. 7(c) shows an example in which a gap-B46 is formed between the vibration unit 19 and the back surface of the brush unit 13. The surface of the vibration unit 19 on the front side of the brush unit 13 is referred to as the front surface of the vibration unit 19, or the first surface of the vibration unit 19, and the surface of the vibration unit 19 on the back side of the brush unit 13 is referred to as the back surface of the vibration unit 19, or the second surface of the vibration unit 19. If the gap-A42 formed between the front surface of the vibration unit 19 and the brush unit 13 is referred to as the first gap, the gap-B46 formed between the back surface of the vibration unit 19 and the brush unit 13 corresponds to the second gap. That is, FIG. 7(c) shows an example in which a first gap and a second gap are arranged, and the first opening, opening-A41, and the second opening, opening-G68, are connected by flow paths that connect the first gap to the second gap and the first gap to the second gap. In this case, the flow path can be the flow path B69 in FIG. 7(e), the flow path A66 in FIG. 7(a), or the flow path C70 in FIG. 7(f).

[0043] 7(d) to 7(f) show examples in which flow path-B69 and flow path-C70 are provided on all surfaces other than the front and back surfaces of the vibration section 19, but flow path-B69 and flow path-C70 may be provided on at least one surface other than the front and back surfaces of the vibration section 19. For example, in FIG. 7(d), they may be provided on at least one of the right and left surfaces of the vibration section 19, and in FIGS. 7(e) and 7(f), they may be provided on at least one of the upper and lower sides of the drawings.

[0044] Although an example is shown in which flow path-A66, flow path-B69, or flow path-C70 is formed by providing a recess or groove in the brush part 13, flow path-A66 may be formed by providing a recess or groove in the vibration part 19, or may be formed by providing a recess or groove in both the brush part 13 and the vibration part 19. In other words, it may be formed by a recess or groove provided in at least one of the inner surface of the brush part 13 or the surface of the vibration part 19.

[0045] 7(a) to 7(f) are not limited to these examples, and opening-B61, opening-C62, opening-D63, opening-E65, or the like can be used as the first opening instead of opening-A41. Alternatively, in FIG. 7(c), opening-F67 can be provided instead of opening-G68, i.e., an opening can be provided near the center of the bristle section 43, or gap-B46 can be added to the configuration of FIG. 7(b). Alternatively, the first opening can be located on a side or end surface of the brush head 13 other than the front or back surface, or at least one of the first opening and the second opening can be located on the side or end surface.

[0046] With the above-described configuration, an inexpensive replacement brush with a very simple configuration that does not require high dimensional accuracy can be used to realize a highly reliable ultrasonic toothbrush that is resistant to vibrations and does not impair the desired brushing effect over a long period of time.

[0047] FIG. 8 shows a charger 71 for charging the battery 16 placed inside the main unit 1. FIG. 8(a) is a top view of the charger 71, which has a through-hole 73 in the center of a circular holder 72 when viewed from above. The main unit 1 is inserted into the through-hole 73 for charging. FIG. 8(b) is a cross-sectional view taken along the dotted line in FIG. 8(a), showing the main unit 1 inserted into the through-hole 73. As shown in FIG. 8(b), the charger 71 has a through-hole 73 formed in the center of a low, cylindrical holder 72, penetrating from the top to the bottom of the holder 72. The charger 71 is used by connecting it to, for example, a household wall outlet via a power cord 74. When the main unit 1 is inserted into the through-hole 73 as shown in FIG. 8(b), the battery 16 is wirelessly charged using well-known electromagnetic induction, but detailed explanations of the principles of this method are omitted. The charger 71 is placed on a surface 75, such as a table or a washbasin, so that the bottom of the main unit 1 is in contact with the surface 75. In this configuration, even if moisture adhering to the main body 1 or the brush part 13 drips onto the plate surface 75, it will not accumulate in the charger 71 and soil the charger 71, and the plate surface 75 can be easily cleaned by lifting the main body 1 and the charger 71, so that the main body 1, the charger 71 and their surroundings can be kept cleaner more easily.

[0048] A power transmitting power source 77 is disposed inside the charger 71, supplying power received via a power cord 74 to a power transmitting coil 76, and the power is transmitted to the main body 1 contactlessly via an alternating magnetic field using the power transmitting coil 76. The main body 1 also contains a power receiving coil 79 and a charging circuit-A 78 that receive power contactlessly from the power transmitting coil 76. The charging circuit-A 78 has a remaining charge detector that detects the remaining charge of the battery 16 and a charger detector that detects that the main body 1 is attached to the charger 71, and controls the supply of power received by the power receiving coil 79 to the battery 16. The power transmitting coil 76, the power transmitting power source 77, and the wiring connected to them are located inside the charger 71, while the power receiving coil 79, the charging circuit-A 78, and the wiring connected to them are located inside the main body 1, and are not normally visible from the outside.

[0049] Figure 9 shows a block diagram of the charging circuit-A78. The charging circuit-A78 has a rectifier circuit 81 that rectifies the power from the receiving coil 79, and the output of the rectifier circuit 81 is supplied to the battery 16 via a remaining charge detector-A84, which is a remaining charge detector, and a switch element 80. A charging control unit-A83 controls the on / off of the switch element 80, thereby controlling the charging of the battery 16. The remaining charge detector-A84 detects the remaining charge of the battery 16 and notifies the charging control unit-A83. A charging timer 85 that measures the charging time is also connected to the charging control unit-A83.

[0050] The remaining charge detection unit-A84 detects the voltage VA generated in the switch element 80 based on the power received by the power receiving coil 79 and the current I flowing through the switch element 80, and a signal based on these is sent to the charging control unit-A83. As will be described later, the signal indicating the voltage VA corresponds to a signal indicating whether the main unit 1 is attached to the charger 71 or not, or a signal indicating whether it is attached or not. The signal indicating the current I corresponds to a signal indicating charging of the battery 16, a signal indicating whether the battery 16 is being charged or not, or a signal indicating the remaining charge of the battery 16.

[0051] Since the voltage VA is generated when the main body 1 is placed in the charger 71, it is detected whether the main body 1 is placed in the charger 71 or whether the main body 1 is placed in the through-hole 73, and the signal indicating the voltage VA corresponds to a signal indicating that the main body 1 is attached to the charger 71. That is, in this configuration, the remaining amount detection unit-A84 also functions as a charger detection unit that detects that the main body 1 is attached to the charger 71.

[0052] The voltage VA may be used as a signal indicating that the main unit 1 is attached to the charger 71, but in this embodiment, it may be compared with a preset threshold Vth1, and the comparison result may be used as a signal indicating that the main unit 1 is attached to the charger 71. For example, the remaining charge detection unit-A84 may compare the voltage VA with the threshold Vth1, and if the voltage VA is equal to or greater than the threshold Vth1, send a signal indicating that the voltage VA is equal to or greater than the threshold Vth1 to the charging control unit-A83 as a signal SG1 indicating whether the main unit 1 is attached to the charger 71. The threshold Vth1 may be set lower than the voltage generated when the main unit 1 is attached to the charger 71.

[0053] On the other hand, current I occurs when charging is being performed, and tends to be large when the remaining charge of battery 16 is low and small when the remaining charge of battery 16 is high. Therefore, the remaining charge of battery 16 can be detected by current I, and current I corresponds to a signal indicating the remaining charge of battery 16.

[0054] The current I may be used as it is as a signal indicating the remaining capacity of the battery 16, or as in this embodiment, it may be compared with a preset threshold Ith1, and the comparison result or a signal indicating the comparison result may be used as a signal indicating the remaining capacity of the battery 16. For example, the remaining capacity detection unit-A84 may compare the current I with the threshold Ith1, and if the current I is less than the threshold Ith1, this indicates that the battery 16 is sufficiently charged or has a sufficient remaining capacity, and therefore may send a signal indicating that the current I is less than the threshold Ith1 to the charging control unit-A83 as the signal SG2 indicating the remaining capacity of the battery 16.

[0055] Without being limited to the above embodiment, the signal SG1 indicating whether or not the main body 1 is attached to the charger 71 may use information or a signal based on the electromotive force or electromotive voltage generated between the terminals of the power receiving coil 79, or a separate sensor such as an optical sensor or Doppler sensor may be provided to determine whether or not the main body 1 is attached to the charger 71. Furthermore, the output voltage or output current of the battery 16 may be used as a signal indicating the remaining charge of the battery 16.

[0056] When the main unit 1 is inserted into the through-hole 73 of the charger 71, the receiving coil 79 receives power from the transmitting coil 76 and sends it as received power to the switch element 80 via the remaining charge detection unit A84. When the main unit 1 is attached to the charger 71, the switch element 80 is in the on state, and the received power is supplied to the battery 16. The remaining charge detection unit A84 measures the voltage VA and compares it with a threshold Vth1, and if the voltage VA is equal to or greater than the threshold Vth1, it notifies the charging control unit A83 of the signal SG1. When the charging control unit A83 detects the signal SG1, the charging control unit A83 instructs the charging timer 85 to start measuring the charging time. Based on this instruction, the charging timer 85 starts measuring a preset charging time, for example, three hours.

[0057] Furthermore, the remaining charge detection unit-A84 measures the current I supplied to the battery 16 via the switch element 80, compares it with a threshold value Ith1, and if the current I is less than the threshold value Ith1, sends a signal indicating that the current I is less than the threshold value Ith1 as SG2 to the charge control unit-A83. When the charge control unit-A83 detects SG2, SG2 indicates that the remaining charge of the battery 16 is sufficient and charging is not necessary, so the charge control unit-A83 controls the switch element 80 to turn off, cutting off the power supply to the battery 16 and stopping charging, and also instructs the charge timer 85 to stop timing.

[0058] Conversely, if SG2 is not detected from the remaining capacity detection unit A84, the charging control unit A83 does not control the switch element 80, so the switch element 80 remains on, power supply to the battery 16 continues, and charging continues. However, if charging continues, the current I may fall below the threshold value Ith1. In this embodiment, if charging continues, the remaining capacity detection unit A84 may not send any signal to the charging control unit A83. Alternatively, the remaining capacity detection unit A84 may send a signal indicating that charging is necessary or will be continued to the charging control unit A83.

[0059] When the charging time has elapsed, the charging timer 85 sends a signal indicating that the charging time has elapsed to the charging control unit A83, and based on that notification, the charging control unit A83 controls the switch element 80 to turn off. In this case, the battery 16 may not be fully charged, but always keeping it fully charged is not necessarily desirable for maintaining good performance of the battery 16 over a long period of time. The charging time should be longer than the time required to charge enough power to achieve the desired brushing when using the main unit 1, and there is no particular problem if the battery is not fully charged.

[0060] On the other hand, when the switch element 80 is on, i.e., when charging is being performed, the remaining charge detection unit A84 does not always notify the charging control unit A83 of SG2 even if the current I falls below the threshold Ith1 in this embodiment. That is, SG2 may be notified only immediately after SG1 is notified, or within a predetermined time after SG1 is notified. Alternatively, SG2 may be notified to the remaining charge detection unit A84 at any time regardless of SG1, but the charging control unit A83 may also be controlled not to acquire SG1 after a certain time has elapsed since acquiring it, or to ignore or invalidate it even if it is acquired.

[0061] The remaining charge detection unit-A84 compares the current I with a preset threshold Ith2, and when the current I falls below the threshold Ith2, it sends a signal SG3 indicating this to the charging control unit-A83. The threshold Ith2 is set lower than the threshold Ith1, and the current I falling below the threshold Ith2 may be set to indicate that the battery 16 is fully charged or nearly fully charged. Therefore, SG3 is a signal indicating that the battery 16 is fully charged or nearly fully charged. When the charging control unit-A83 detects this SG3, it turns off the switch element 80 to cut off the current supply to the battery 16, stopping charging, and instructs the charging timer 85 to stop measuring time.

[0062] Although the charging time has been described using an example of three hours, it is not limited to this and may be set appropriately depending on the capacities and capabilities of the transmitting coil 76, the receiving coil 79, and the battery 16, and may be, for example, one hour, five hours, or 11 hours. Furthermore, while different values ​​are set for the thresholds Ith1 and Ith2, this is not limiting and the same value may be used for the thresholds Ith1 and Ith2. Furthermore, the comparison of the voltage VA with the threshold Vth1 and the comparison of the current I with the thresholds Ith1 and Ith2 may be performed by a circuit other than the charging control unit A83, such as the remaining charge detection unit A84, as described above. Alternatively, the remaining charge detection unit A84 may transmit a signal indicating the voltage VA or the current I as SG1, SG2, or SG3 to the charging control unit A83, and the charging control unit A83 may acquire the signal, i.e., compare the signal with the thresholds Vth1, Ith1, and other thresholds, and control the switching element 80, i.e., perform charging control, based on the comparison result.

[0063] When the main unit 1 is removed from the charger 71, the receiving coil 79 cannot receive power from the transmitting coil 76, and the voltage VA detected by the remaining charge detector A84 falls below the threshold Vth1. The remaining charge detector A84 sends a signal SG4 to the charging controller A83 indicating that the voltage VA has fallen below the threshold Vth1. When the charging controller A83 detects the signal SG4, it controls the switch element 80 to turn on, preparing for the case in which the main unit 1 is again attached to the through-hole 73 of the charger 71 and charging is resumed.

[0064] Alternatively, instead of transmitting SG4, the remaining charge detection unit-A84 may always or repeatedly transmit SG1 when the voltage VA exceeds the threshold Vth1, but may stop transmitting SG1 to the charging control unit-A83 or not transmit SG1 to the charging control unit-A83 when the voltage VA falls below the threshold Vth1.

[0065] FIG. 10 shows an example of the above control in the form of a flowchart. First, when the charging control unit-A83 detects a signal SG1 indicating that the main unit 1 has been attached to the charger 71 in S1, the charging control unit-A83 instructs the charging timer 85 to start measuring the charging time in S2. When the charging control unit-A83 acquires a signal SG2 indicating that the remaining charge of the battery 16 is sufficient (S3), it instructs the charging timer 85 to stop measuring the charging time in S6, turns off the switch element 80 (S6), and stops charging (S7). Even if SG2 is not detected in S3, or if SG3 indicating that the battery 16 is fully charged is detected in S4, S6 is similarly executed and charging is stopped (S7). Even if neither SG2 nor SG3 is detected, when the charging time has elapsed (S5), the switch element 80 is controlled to be turned off (S6), and charging is stopped (S7).

[0066] 11 is a block diagram showing an example of a charging circuit-B101 that performs another charging control. In the charging circuit-A78, the remaining charge detection unit-A84 serves both as a remaining charge detection unit that detects the remaining charge of the battery 16 and as a charger detection unit that detects that the main unit 1 is attached to the charger 71, but in the charging circuit-B101, a remaining charge detection unit-B102 that serves as a remaining charge detection unit that detects the remaining charge of the battery 16 and a charger detection unit 103 that serves as a charger detection unit are provided and connected to the charging control unit-B104.

[0067] As with the charging circuit-A78, the output of the rectifier circuit 81 is sent to the battery 16 via the switch element 80 and the like to charge the battery 16. The remaining charge detection unit-B102 is connected to the battery 16 to detect the output voltage VB of the battery 16 and notify the charging control unit-B104 of a signal indicating the voltage VB as a signal indicating the remaining charge of the battery 16. Also, the charger detection unit 103 is connected to the switch element 80 to detect the voltage VA and notify the charging control unit-B104 of a signal indicating the voltage VA. Here, the voltage VA corresponds to a signal indicating whether the main unit 1 is attached to the charger 71 or not, or a signal indicating whether it is attached or not, and the voltage VB corresponds to a signal indicating charging of the battery 16 or a signal indicating whether charging is occurring, or the voltage VB corresponds to a signal indicating the remaining charge of the battery 16.

[0068] 12 shows an example of a flowchart of charging control in the charging circuit-B101. In the charging circuit-B101, the charging control unit-B104 acquires SG1, which is a signal indicating the voltage VA notified from the charger detection unit 103 and which is a signal indicating whether the main unit 1 is attached to the charger 71, compares the voltage VA with a preset Vth1, and if the voltage VA is equal to or higher than Vth1, the voltage VA indicates that the main unit 1 is attached to the charger 71, and instructs the charging timer 85 to measure the charging time (S2).

[0069] Next, the charging control unit-B104 acquires voltage VB and compares it with a preset threshold Vth2 (S3). If voltage VB exceeds threshold Vth2, the remaining charge is sufficient, i.e., charging is not necessary, so the charging control unit controls switch element 80 to be OFF, stops measuring the charging time by charge timer 85 (S6), and stops charging (S7). Conversely, if voltage VB is equal to or lower than threshold Vth2, this indicates that charging is necessary, or that VB is not fully charged or is not close to being fully charged, so the charging control unit does not control switch element 80, and switch element 80 remains ON, allowing charging to continue. If VB at full charge is, for example, 4.2 V, then threshold Vth2 can be set to 3.7 V, but is not limited to this and may be determined appropriately depending on the characteristics of battery 16 and the specifications of main unit 1.

[0070] As charging continues, if the charging control unit-B104 detects that VB notified by the remaining charge detection unit-B102 exceeds the threshold value Vth3 (S4), VB indicates that the battery 16 is fully charged or nearly fully charged. Therefore, the charging control unit-B104 turns off the switch element 80 to cut off the power supply to the battery 16, stops timing (S6), and stops charging (S7). The threshold value Vth3 is normally set to a value greater than the threshold value Vth2. The threshold value Vth3 may be, for example, VB at a fully charged state, but is not limited to this and may be determined appropriately depending on the characteristics of the battery 16 and the specifications of the main unit 1. Furthermore, if the charging time has elapsed (S5), the charging control unit-B104 turns off the switch element 80 (S6) and stops charging (S7) in the same way as the charging circuit-A78.

[0071] When the main body 1 is removed from the charger 71 and the charging control unit B104 detects that the voltage VA acquired from the charger detection unit 103 has fallen below the threshold Vth1, the charging control unit B104 controls the switch element 80 to turn on.

[0072] Since the user cannot determine whether charging is taking place in the above case, a separate LED may be provided on the main unit 1 to light up when charging of the battery 16 is taking place, i.e., when current I is detected, to notify the user that charging is taking place. However, in the above control, when the main unit 1 is inserted into the charger 71 and the current I detected by the remaining charge detection unit A84 falls below the threshold Ith1, i.e., when the remaining charge of the battery 16 is sufficient and charging is not necessary, this is immediately notified to the charging control unit A83, which controls the switch element 80 to turn off, stopping charging, and the current I is no longer detected or becomes zero. In this case, the LED lights up for a moment when the main unit 1 is inserted into the charger 71 and then immediately goes out, which may mislead the user into thinking that charging is not taking place normally or that a malfunction has occurred.

[0073] Therefore, the LED may be configured to light after a certain time (e.g., 3 seconds) has elapsed since the detection of the current I, or may be configured to light if the current I is detected again after the certain time has elapsed. Alternatively, the LED may be configured to light up once upon detection of the current I and not turn off for a certain time (e.g., 3 minutes). In this case, the LED does not turn off for the certain time, which is desirable as it allows the user to easily determine that there is no abnormality in the charging control and does not mistakenly believe that the charger 71 or main unit 1 is faulty.

[0074] The LEDs may be controlled by the charging control unit-A83 or the charging control unit-B104, or a separate circuit for controlling the LEDs may be provided.

[0075] Generally, with batteries, especially secondary batteries such as lithium-ion batteries, keeping them fully charged for long periods of time or constantly is not necessarily desirable, as it reduces capacity, shortens battery life, reduces output, and otherwise degrades battery performance. To avoid this, charging controls are implemented that calculate the charge amount and charging time, for example, to prevent the battery from reaching full charge. However, this requires circuitry to calculate the charge time and charge amount, as well as circuitry capable of controlling charging based on the calculation results, which leads to an increase in the size and complexity of the charging system. Furthermore, the increase in the number of components leads to an increase in failure rate and at the same time, increases costs, making it difficult to provide good brushing services at low cost over a long period of time.

[0076] With the above control, the battery 16 is not always fully charged, and no load or stress is placed on the battery 16. Charging control of the battery 16 is possible with a very simple configuration, and the performance of the battery 16 can be maintained for a long period of time. This avoids problems caused by complex charging control, and allows the main body 1 to provide good brushing at low cost for a long period of time.

[0077] Each of the above-described configurations makes it possible to realize a highly reliable ultrasonic toothbrush that has a very simple and inexpensive configuration and that does not impair the desired brushing effect over a long period of time. Furthermore, the present invention employs the following measures to solve the above-mentioned problems: That is, the toothbrush of the present invention is an ultrasonic toothbrush having a grip portion, a protruding portion protruding from the tip of the grip portion, a vibration portion formed at the tip of the protruding portion and having a vibrator that generates ultrasonic waves disposed thereon, and a bristle portion in which multiple bristle bundles are planted to form a brush, wherein the bristle portion is disposed with a gap between it and the vibration portion and has an opening that communicates with the gap. Furthermore, the ultrasonic toothbrush of the present invention is characterized in that the bristle unit is detachable from the vibration unit. [Explanation of symbols]

[0078] 1 Main unit 11 Gripping part 12 Protrusion 13 Brush section 14 Brushes 15 Control section 16 Battery 17 Controller 18 oscillators 19 Vibration unit 20 Harness-B 22 Switch 23 LED section 41 Opening-A 42 Gap-A 43 Hair transplantation area 44 Insertion section 45 Hair Bundle 46 Gap-B 60 Opening-H 61 Opening-B 62 Opening-C 63 Opening-D 64 pockets 65 Opening-E 66 Flow path-A 67 Opening-F 68 Opening-G 69 Flow path-B 70 Flow path-C 71 Charger 72 Holder 73 Through Hole 74 power cord 75 Board surface 76 Transmission coil 77 Power Transmission Source 78 Charging circuit-A 79 Receiving coil 80 Switch element 81 Rectifier circuit 82 Adhesive 83 Charging control unit-A 84 Remaining amount detection unit-A 85 Charging timer 101 Charging circuit-B 102 Remaining amount detection unit-B 103 Charger detection unit 104 Charging control unit-B 201 User IF Department 202 Control section 204 Signal Generation Unit 206 Power supply section 207 Timer

Claims

1. A gripping portion; a protrusion protruding from the tip of the gripping portion; a vibration section formed at the tip of the protrusion and having a vibrator disposed therein that generates ultrasonic waves; a bristle implantation section in which a plurality of bristle bundles are implanted to form a brush; a brush part in which the bristle part is disposed on a first surface and into which the vibration part is detachably inserted through a first opening; a gap provided between the vibration section and the bristle section; An ultrasonic toothbrush characterized in that it has a second opening on the first surface that is different from the first opening and leads to the gap, and a third opening on a second surface of the brush part that is different from the first surface, that is different from the first opening and different from the second opening, leading to the gap.

2. An ultrasonic toothbrush as described in claim 1, characterized in that the brush portion has a flow path connecting the gap and the third opening.

Images