The present invention relates to an electric toothbrush, in particular an electric toothbrush emitting ultrasonic waves.
Electric toothbrushes have been put into practical use. The electric toothbrushes vibrate during brushing to improve the brushing effect (hereinafter, simply referred to as the brushing effect) including removal and cleaning of plaque. Further, an ultrasonic toothbrush which improves brushing efficiency by using ultrasonic waves to realize good toothbrushing has been proposed, for example, as disclosed in Patent Document 1. As the frequency of the ultrasonic wave used in the ultrasonic toothbrush, for example, as in Patent Document 2 and Patent Document 3, the frequency from 1 MHz to 2MHz, for example, 1.6 MHz or the like is usually used.
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
Compare to toothbrushes which don't use ultrasonic waves, excellent brushing effect peculiar to ultrasonic waves has been confirmed. On the other hand, the examination regarding the frequency with the highest brushing effect was not sufficiently carried out at present, and it was not clear how much the frequency should be set, even if we want to realize a suitable toothbrush with higher efficiency.
When the frequency of the ultrasonic wave is higher, the thickness of the vibrator is thinner. When the vibrators are mounted into the toothbrush, breakage due to the load applied to the vibrator easily occurs and the defect rate is increased. For example, when the vibrator at a position different from the predetermined position is moved to the correct position, extra force is applied to the vibrator. Breakage of the vibrator is likely to occur because such as cracking or breaking the vibrator due to the excess force. For example, when the vibrator is arranged by a method such as Patent Document 1, this tendency becomes more remarkable because the vibrator is moved in, for example, an adhesive to be filled. Therefore, in order to avoid damage to the vibrator, even if the vibrator is disposed at a position different from the predetermined position, the vibrator may be fixed as it is. Since the position of the vibrator is not a predetermined position, a predetermined ultrasonic wave is not necessarily transmitted to the toothbrush, so that a situation in which a sufficient brushing effect cannot be obtained, causes.
Or, even at a predetermined position, the vibrator is easily fixed in a state where extra force is applied. For example, when the vibrator is fixed in a state of being curved, a situation in which the vibrator cannot output a predetermined ultrasonic wave. Furthermore, since it is easily mounted in a place different from the predetermined position, or when it is fixed in a state where extra force is applied, another problem such as predetermined durability cannot be obtained, occurs because the vibrator is easily cracked.
In order to solve the above problem, the following means were taken in the present invention. That is, the toothbrush of the present invention is characterized in that it is an ultrasonic toothbrush having at least a gripping portion having a signal generating portion for outputting a drive signal to be supplied to the vibrator, a protruding portion provided at an end of the gripping portion, a vibrating portion in which the vibrator is disposed at a tip of the protruding portion, and a brush disposed at a position facing the vibrating portion, wherein the frequency of the driving signal is 3 MHz to 5 MHz.
Further, the ultrasonic toothbrush of the present invention is characterized in that it has a flow path for discharging air existing at a position where the vibrator is disposed when the vibrator is disposed in a space portion inside the vibrating portion.
Further, 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 present invention can provide an ultrasonic toothbrush that enhances cleaning effects such as brushing, e.g., removing plaque, more effectively by specifying the frequency of the ultrasonic waves used in the ultrasonic toothbrush.
Further, even when the thickness of the vibrator to be used become thinner by the higher frequency used, the easily and simple structure avoids damage during mounting the vibrator, and prevents a decrease in the non-defective rate, and can provide a product capable of maintaining the desired performance over a long period of time.
Inside the gripping portion 11, a battery 16, a controller 17 for controlling the main body 1 in accordance with the operation of the operation portion 15 are provided. The battery 16 and the controller 17, the controller 17 and the vibrator 18 are respectively connected by a harness A 21, a harness B 20.
A switch 22 a red LED 23 inside the switch 22 are disposed to the operation portion 15. It is possible to perform the control including the emission or stop of the emitted ultrasonic wave by pressing the switch 22 of the operation portion 15 by the user, the lighting state of LED 23 is changed in response to the operation of the switch 22, for example, the switch 22 is turned on red by LED 23, and it informs the user the driving state and the operating state of the main body 1.
In addition to the CPU and the memory, the control unit 202 includes an interface unit for connection with each unit, and controls the main body 1. Power supply unit 206 controls electric power supplied from the battery 16 to the predetermined constant voltage value, for example, 5V and supplies to each unit via a control unit 202. The user IF unit 201 is connected to the operation portion 15. And when the user operates the operation portion 15, the user IF unit 201 notifies the information to the control unit 202.
Battery 16 may be a dry cell, or may be a secondary battery that can be repeatedly used by charging, such as a lithium-ion battery. Alternatively, instead of these batteries, a power adapter capable of outputting a predetermined voltage, e.g., 5V, from, e.g., a household outlet of 100V or the like may be disposed outside the main body 1 and used.
The timer 207 measures a predetermined time, for example, 3 minutes as the time for brushing, i.e., the time for driving the vibrator 18 in order to output the ultrasonic wave. The time is not limited to 3 minutes, and may be less than 3 minutes or more than 3 minutes, and may be configured to be set by the user as appropriate.
In
When the user presses the switch 22, the information is sent to the control unit 202 via the user IF unit 201, the control unit 202 instructs the signal generator 204 to output an electrical signal as shown in
When a predetermined period of time, for example, three minutes, elapses, the timer 207 notifies the control unit 202 that, and the control unit 202 gives instructions to the signal generator 204 to stop the signal output based on the notification. Or the control unit 202 stops generating the signals by the signal generator 204 by stopping the supply of power to the signal generator 204.
If the user presses the switch 22 again before a predetermined time has elapsed, the information is notified from the user IF unit 201 to the control unit 202, the control unit 202 instructs the signal generator 204 to stop the signal output or stops generating a signal by the signal generator 204 by stopping the supply of power to the signal generator 204. At the same time, the control unit 202 instructs the timer 207 to stop the time measurement, and resets the timer 207.
As the operation of the switch 22 by the user's in the above, pushing the switch 22 is not limited to simply pressing the switch 22, pushing the switch 22 twice in a short time, so-called double click, or pressing the switch 22 for a few seconds, so-called long press may be available so that the double click may be used in order to start the output, and the long press may be used in order to stop the signal. That is, depending on the purpose of operating the switch 22, it is good to change the operation method of the switch 22. Such the configuration like that is desirable because it can avoid malfunction of the apparatus when the switch 22 is erroneously touched. In particular, in the case where the operation portion 15 is disposed in the gripping portion 11 as in the present embodiment, there are many cases where the user touches the operation portion 15 unintentionally. And even if the ultrasonic wave is unintentionally stopped when the switch 22 is pressed by mistake, the user cannot recognize the ultrasonic wave because it is difficult for the user to notice the ultrasonic wave. And even though the ultrasonic wave is stopped, the brushing is continued and a predetermined brushing effect cannot be easily obtained. Therefore, when the user stops the ultrasonic wave, as the switch operation, an operation which is difficult to be obtained without the user's intention, like the double-click or the long-press is desirable.
The signal generator 204 in this embodiment outputs 4.8 MHz as a drive signal as described above. The frequency of the ultrasound used was determined as follows. All subjects were trained the correct brushing procedure prior to testing so that individual differences in brushing are minimized by equalizing brushing effect among subjects.
In addition to ultrasonic toothbrushes capable of using 1.6 MHz as a frequency, ultrasonic toothbrushes capable of using 3.2 MHz and ultrasonic toothbrushes capable of using 4.8 MHz were prepared. And the group A uses the ultrasonic toothbrush that emits only 1.6 MHz ultrasonic waves to brush, the group B uses the ultrasonic toothbrush that emits only 3.2 MHz ultrasonic waves to brush, and the group C uses the ultrasonic toothbrush that emits only 4.8 MHz ultrasonic waves. Each group consists of 17 or 16 persons. However, each subject in each group was not informed of the frequency of the ultrasonic wave emitted by the ultrasonic toothbrush to be used. Further, since the frequency to be used was in the ultrasonic band, any subjects could not hear the sound of each frequency, and it was not possible for each subject to judge which frequency the subject was using. 3 minutes brushing was performed twice a day for 8 consecutive weeks to test which group gave the greatest oral cleaning effect.
As an index for determining the effectiveness of brushing, the plaque index (hereinafter referred to as “PII”) was used. A small PII indicates less plaque. In addition, the gingivitis index (hereinafter referred to as GI) was also used as another indicator of the effectiveness of brushing. A small GI indicates a low degree of gingivitis.
The PII of Group A was 0.2-1.0 before the test, 0.0-0.75 after the test, 0.3-1.0 before the test in Group B, 0.0-0.5 after the test, 0.3-1.2 before the test in Group C, 0.0-0.75 after the test, and PII for 3.2 MHz and 4.8 MHz was decreased more than 1.6 MHz.
The GI of Group A was 0.3-1.3 before the test, 0.35-1.5 after the test, 0.6-1.4 before the test in Group B, 0.15-1.2 after the test, 0.45-1.7 before the test in Group C, and 0.2-1.1 after the test. The GI tended to decrease at 3.2 MHz and 4.8 MHz than 1.6 MHz.
That is, it is understood that the brushing effect is higher at 3.2 MHz or 4.8 MHz than at 1.6 MHz. However, the difference between 3.2 MHz or 4.8 MHz and 1.6 MHz is respectively greater than difference between 3.2 MHz and 4.8 MHz. Regarding frequency, 3.2 MHz or more is more desirable than 1.6 MHz as the frequency used for brushing.
As described above, by setting the frequency of the ultrasonic wave to be used to 3 MHz or more, for example, 3.2 MHz or 4.8 MHz, it is possible to realize an ultrasonic toothbrush that provides a higher brushing effect. Incidentally, the frequency of the ultrasonic wave to be used is not necessarily higher, because, for example, as the thickness of the vibrator to be used when exceeding 5 MHz becomes very thin, not only the mass production of the vibrator becomes difficult even in the manufacturing stage of the ultrasonic toothbrush, but also, it is likely to cause cracks and breakage in particular, when mounting the vibrator to the ultrasonic toothbrush, i.e. when mounting it to the vibrating portion A 19 in the present embodiment. Alternatively, when a strong impact such as dropping the main body 1 during use is given, cracks are likely to occur in the vibrator, resulting in desired ultrasonic wave not to be oscillated and problems such as occurring the failure frequently. Thus, the vibrator for oscillating a frequency exceeding 5 MHz as the frequency of the ultrasonic wave used is not suitable for mass production of the vibrator itself or the ultrasonic toothbrush and actual use of the toothbrush, eventually, of which about 3 MHz to 5 MHz is preferred, and 3.2 MHz to 4.8 MHz is the most desirable.
Further in the present invention, with the simple configuration of even the vibrator for outputting the frequency of 3.2 MHz and 4.8 MHz, the mounting method of the vibrator in the ultrasonic toothbrush and the configuration of the ultrasonic toothbrush are offered which does not reduce the non-defective ratio and the durability.
In the present 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, it is about 650 μm, and when the frequency is 1.6 MHz, it is about 1.3 mm. The thickness of the vibrator 18 easily varies depending on the frequency, and may also vary depending on the material and manufacturing method used. However, the thickness tends to be thinner at higher frequencies, which is most pronounced and tends to be dominant for the thickness of the vibrator.
When the thickness of the vibrator 18 is reduced, the strength of the vibrator 18 is reduced, consequently, the breakage is likely to occur, for example, when mounting the vibrator 18 to the space portion A 41. The reason for this is as follows. When inserting the vibrator 18 into the space portion A 41, an adhesive is applied to the brush surface and the back surface of the brush of the vibrator 18, and before the adhesive is solidified, the vibrator 18 is inserted into the space portion A 41, for example, from the left side of the drawing in the
In addition, when the vibrator 18 is inserted into the space portion A 41, air in the space portion A 41 may lose its place and push away the adhesive, and may be discharged, for example, by pushing away the adhesive applied to the brush surface, so that the desired adhesive layer A 42 is not formed. If the adhesive is solidified as it is, a void, an air layer or a bubble is formed in the adhesive layer A 42, and even if the vibrator 18 oscillates the predetermined ultrasonic wave, the predetermined ultrasonic wave is not transmitted to the brush portion 13 due to the void, the air layer or the bubble, and the predetermined ultrasonic wave is not emitted from the brush 14, thereby causing a problem in which an ultrasonic wave effect cannot be obtained.
Therefore, in the present embodiment, when the vibrator 18 is inserted into the space portion A 41, the flow path of the air pushed out by the vibrator 18 is secured in advance, whereby the air in the space portion A 41 is discharged by the flow path at the time of mounting the vibrator 18, and the vibrator 18 is smoothly inserted into the space portion A 41 without being pushed back by the air. Therefore, without applying an excessive force to the vibrator 18, breakage of the vibrator 18 at the time of mounting of the vibrator 18 does not occur. The air flow path not only facilitates the insertion of the vibrator 18 to increase the non-defective product rate, but also the vibrator 18 is fixed to the space portion A 41 in a state in which no excessive load is applied to it by the flow path, so that predetermined ultrasonic waves are output satisfactorily and the product life, reliability, and durability are not lowered.
Further, since the air discharged at the time of inserting the vibrator is suitably discharged from the air flow path, the desired positions of the adhesive layer A 42 and the adhesive layer B 43 can be easily formed without any influence on the adhesive layer A 42 and the adhesive layer B 43, and, an ultrasonic toothbrush capable of transmitting a predetermined ultrasonic wave to the brush 14 and sufficiently obtaining the ultrasonic effect can be provided so that the vibrator 18 can be correctly arranged and fixed consequently.
When the vibrator 18 is inserted into the space portion A 41, the air filled in the space portion A 41 is discharged through these flow passages, so that the adhesive layer A 42 and the adhesive layer B 43 provided on the brush surface and the back surface of the brush are not pushed away, and the adhesive layer A 42 and the adhesive layer B 43 can be formed satisfactorily.
Due to the flow path A 51 and B 52, the vibrator 18 can be easily inserted into the space portion A 41 without imposing an excessive load on the vibrator 18 at the time of mounting the vibrator 18, and moreover, a desired adhesive layer can be formed, so that not only the decrease in the quality rate can be prevented, but also a predetermined ultrasonic wave can be output and the product defect does not occur. Further fixed vibrator 18 without applying an excessive load, of which the breakage due to the given vibration is less likely to occur, does not reduce the life of the product, the durability and reliability without shortening the life of the vibrator 18.
The above flow passages is suitably disposed on both side surfaces of the vibrator 18 that have the least influence on the oscillation of the vibrator 18 or may be disposed on both sides of the vibrator 18 as shown in the above
Alternatively, a plurality of flow passages may be provided at positions other than the region sandwiched between the vibrator and the brush, the flow path A 51 and the flow path C 53 may be arranged, the flow path B 52 and the flow path C 53 may be arranged, or the flow path A 51, the flow path B 52, and the flow path C 53 may be arranged. In the configuration in which a plurality of flow passages are arranged as described above, even when the vibrator 18 is inserted into the space portion A 41 and the flow passage is blocked by the adhesive unintentionally entering the flow passage, for example, even when the flow path A 51 is blocked, air can be discharged by other flow passages, for example, by the flow path B 52 or the flow path C 53, so that the mounting of the vibrator 18 is not hindered by the air in the space portion A 41. That is, the configuration in which a plurality of flow passages are provided is more desirable.
Further, the flow passage is configured such that the cross section as shown in
On the other hand, if the cross section of the flow passage is, for example, a quadrangle, the manufacturing cost may be high, and in this case, the cross section may be configured to be a semicircle or a part of a circle, for example, an arc, but when the adhesive unintentionally enters the flow passage, the flow passage is likely to be blocked, and therefore, it is better to provide a plurality of flow passages in consideration of this point.
The vibrator 18 is inserted into the space portion B 62 while being fixed to the sponge 64 as shown in the
The sponge 64, which is a pressing means, is very effective for forming the good adhesive layer A 42 on the surface of the vibrator as in this embodiment. As described above, the vibrator 18 is inserted into the space portion A 41 before the adhesive applied to the surface solidifies. At this time, the adhesive on the surface of the vibrator 18 comes into contact with the upper surface 66 and the like of the space portion A 41 and is scraped off unevenly to form unevenness in the adhesive layer A 42 on the surface of the vibrator 18, and an air layer may be formed on the surface of the vibrator 18, and as described above, a problem due to the air layer, voids, bubbles, or the like formed on the surface of the vibrator 18 occurs. 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 is temporarily non-uniform at the stage of insertion of the vibrator 18 into a uniform layer without unevenness and to obtain a good adhesive layer A 42.
Since the pressing means is very effective for forming the uniform adhesive layer A 42, for example, it can also be used for the vibrating portion A 19 as shown in
In the above, the adhesive layer A 42 and the adhesive layer B 43 may be a layer of a curable fluidizing agent, and it is sufficient that the vibrator 18 can be reliably fixed to the space portion A 41, the sponge 64, or the like. In addition to adhesives, thermosetting resins, thermoplastics, or other curable resins can be used, such as epoxy resins, rubbers, or adhesives based thereon. Incidentally, since the adhesive layer B 43 fixes the vibrator 18 and the sponge 64 in the
The flow path is formed by adjusting the width of the layer used for fixing the vibrator 18 in the configuration of the
In the configuration as shown in the
In contrast, in
Since a part of the adhesive 82 can flow out through the gap 77 by the insertion of the vibrator 18, the adhesive can be prevented or reduced from overflowing from the opening A 73, and the adhesive 82 can also be avoided or reduced from adhering to the outer periphery of the vibrating portion C 71. After insertion of the vibrator 18, the vibrator 18 is fixed in the predetermined place by solidification of the adhesive 82. Incidentally, since the portion without the adhesive 82 in the opening A 73 by the movement of the vibrator 18 occurs as shown in the
The
In the above-described configuration, even when using a vibrator having a high frequency, the ultrasonic toothbrush can be provided of that the vibrator 18 can be easily installed at the predetermined position without damage, and even if the frequency of the ultrasonic wave is increased it does not increase the defect rate. Furthermore, it is possible to provide a highly reliable ultrasonic toothbrush which is strongly resistant to vibration imparted from the outside.
Incidentally, this international application claims priority under Japanese Patent Application No. 2019-002982 filed on Jan. 10, 2019, and the entire contents of Japanese Patent Application No. 2019-002982 are incorporated in this international application.
1 Main unit
11 Gripping portion
12 Protruding portion
13 Brush portion
14 Brush
15 Operation portion
16 Battery
17 Controller
18 Vibrator
19 Vibrating portion A
20 Harness B
21 Harness A
22 Switch
23 LED
41 Space portion 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 Vibrating portion B
62 Space portion B
63 Pedestal portion A
64 Sponge
66 Upper surface
71 Vibrating portion C
72 Space portion C
73 Opening A
74 Insertion path A
75 Insertion path B
76 Protrusion
77 Gap
81 Opening B
82 Adhesive
83 Vibrating portion D
91 Pedestal portion B
92 Pedestal portion C
93 Space portion D
94 Vibrating portion E
201 User IF unit
202 Control unit
204 Signal generator
206 Power Supply unit
207 Timer
Number | Date | Country | Kind |
---|---|---|---|
2019-002982 | Jan 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2020/000642 | 1/10/2020 | WO | 00 |