TWI875897B - toothbrush - Google Patents

Abstract

The present invention provides a toothbrush that can reduce the burden of delicate brushing on parents, and children themselves do not dislike delicate brushing and can enjoy brushing themselves. The toothbrush of the present invention includes: a brush structure having a piezoelectric element that vibrates by an arbitrary sound source data signal; and a body, the brush structure is mounted on one end side, and current is supplied to the piezoelectric element. If the brush head of the brush structure having a built-in piezoelectric element, or the brush part including a plurality of hair bundles with a plurality of hair implantation holes implanted in the hair implantation surface of the brush head, contacts the biological tissue in the oral cavity of the user, the vibration of the piezoelectric element that vibrates by the sound source data signal is transmitted to the bone through the biological tissue, so that the user recognizes the vibration as sound.

Description

toothbrush

The present invention relates to a toothbrush.

This application is based on and claims priority to Japanese Patent Application No. 2019-237348 filed in Japan on December 26, 2019, and the contents thereof are cited in this application.

In brushing teeth, for children aged one and a half to nine years old whose brushing skills are not mature, parents' delicate brushing is very important in protecting children's teeth. It is also proposed that there is a toothbrush for delicate brushing that is easy to hold and handle when parents are delicately brushing their children (for example, Patent Document 1).

[Prior art literature]

[Patent Literature]

[Patent document 1] Japanese Patent Publication No. 2017-213314

However, many children hate fine brushing and avoid or make a fuss, and many parents cannot perform fine brushing to their satisfaction. Therefore, a tool for fine brushing that does not make children hate it is required.

One form of the present invention is developed in view of the problems of the prior art, and its purpose is to provide a toothbrush that can reduce the burden of delicate brushing on parents and that children themselves do not dislike delicate brushing and can enjoy brushing themselves.

As a countermeasure to reduce children's resistance to fine brushing, the inventor of this application came up with the idea of "playing sound during brushing". He focused on the habit of children "to show interest in people who play sound", and many parents use smartphones or personal computers (PCs) to play music that children like during fine brushing. When parents put the toothbrush in the child's mouth, playing music can reduce the child's resistance to fine brushing.

Therefore, as a countermeasure to more effectively reduce children's resistance to fine brushing through music, the inventor of this application conceived of a "bone conduction toothbrush" that allows children to hear music only when the toothbrush hits the child's teeth.

The so-called "bone conduction toothbrush" refers to a toothbrush constructed in the following manner: the piezoelectric element assembled in the inside of the brush head (the back side of the hair-planting surface) allows the sound source data signal to flow in the form of electric current, thereby generating vibration, and the vibration of the piezoelectric element is transmitted to each bristle implanted on the hair-planting surface through the hard material of the brush head. If the "bone conduction toothbrush" is used for brushing teeth, the vibration is sequentially transmitted from the child's teeth to the child's inner ear through the bristles that touch the child's teeth, so the child can recognize the transmitted vibration as "sound".

However, the vibration generated by the piezoelectric element passes through several components before it is transmitted to the teeth (inner ear) of children. That is, the brush head (bristle surface) composed of hard materials and a plurality of bristles are between the piezoelectric element and the teeth, and there is a problem that these components attenuate the vibration from the piezoelectric element. Therefore, there is a situation where the vibration required to produce a sound of a size that attracts the interest of children cannot be transmitted to the inner ear, or the vibration transmitted from the toothbrush cannot be recognized by the child as sound.

Therefore, a countermeasure is needed to suppress the vibration from the piezoelectric element from being attenuated by the hard material and bristles of the brush head, maximize the vibration transmitted to the child's teeth, and make the sound perceived by the child louder.

The toothbrush in one form of the present invention may also be configured as follows, the structure comprising: a brush structure having a piezoelectric element that vibrates by an arbitrary sound source data signal; and a body, the brush structure being mounted on one end side and supplying current to the piezoelectric element. If the brush head portion of the brush structure having the piezoelectric element built therein, or the brush portion including a plurality of hair bundles with a plurality of hair implantation holes implanted in the hair implantation surface of the brush head portion contacts the biological tissue in the oral cavity of the user, the vibration of the piezoelectric element that vibrates by the sound source data signal is transmitted to the bone via the biological tissue, so that the user recognizes the vibration as sound.

In one form of the toothbrush of the present invention, the structure may be such that when a sound source (frequency) of 1000 Hz or more and 7000 Hz or less flows into the piezoelectric element, the vibration level of the brush portion becomes 45 dB SPL or more and 75 dB SPL or less.

In a toothbrush in one form of the present invention, the following structure may be adopted: the piezoelectric element is arranged in contact with the back side of the hair-planting plate whose surface is set as the hair-planting surface, and the ratio of the total area of the plurality of hair-planting holes in the area overlapped with the piezoelectric element in the hair-planting plate when viewed from above becomes 30% or more relative to the total area of all the hair-planting holes set on the hair-planting surface.

In a toothbrush in one form of the present invention, the structure may be as follows: relative to the area of the region overlapping with the piezoelectric element in the hair-implanting surface when viewed from above, the total area of the plurality of hair-implanting holes in the region accounts for more than 23%.

In a toothbrush in one form of the present invention, the structure may also be as follows: the distance from the lower surface of the piezoelectric element to the bottom surface of the hair implantation hole becomes greater than 0.4 mm and less than 1.6 mm.

The structure may also be as follows: in the bundle of bristles bundled with multiple bristles, a flat line is used to implant each implantation hole, and among all the arrangements of the bristles implanted on the implantation surface, there are at least three rows of the arrangements of the bristles that meet the following two conditions 1 and 2.

<Condition 1>

The distance between the horizontal lines punched into each of the plurality of hair implantation holes arranged in the length direction of the brush head is greater than 0.25 mm and less than 1.5 mm.

<Condition 2>

Relative to the length of the hair transplantation area in the longitudinal direction of each hair transplantation hole row, the ratio of the sum of the lengths of multiple adjacent horizontal lines in the longitudinal direction of the hair transplantation hole row is greater than 53% and less than 94%

In a toothbrush in one form of the present invention, the following structure may be adopted: at least a part of the plurality of hair implanting holes arranged in the hair implanting surface is arranged in a grid shape, and the ratio of the area of the area surrounded by the second imaginary line connecting the outer edges of the plurality of hair implanting holes on the outermost side with the shortest distance among all the hair implanting holes arranged in a grid shape to the area of the area surrounded by the first imaginary line connecting the outer edges of the plurality of hair implanting holes on the outermost side with the shortest distance among all the hair implanting holes arranged in the hair implanting surface becomes 20% or more.

In one form of the toothbrush of the present invention, the structure can also be set as follows: relative to the area of the total hair-implanting region surrounded by the first imaginary line connecting the outer edges of the plurality of hair-implanting holes on the outermost side with each other at the shortest distance among all the hair-implanting holes to be arranged on the hair-implanting surface, the total number of all bristles implanted on the hair-implanting surface becomes greater than 600/ ^cm2 and less than 2800/ ^cm2 .

In one form of the toothbrush of the present invention, the structure may be as follows: part or all of the bristles include forked hairs, and relative to the area of the total hair-planting area, the ratio of the total number of the forked hairs of all the bristles planted in the area becomes greater than 600/ ^cm2 and less than 11200/ ^cm2 .

In a toothbrush in one form of the present invention, the following structure can also be used: the thickness of the sum of the maximum thickness of the piezoelectric element and the maximum thickness of the hair implantation plate becomes greater than 3.4 mm and less than 7.0 mm.

In a toothbrush in one form of the present invention, the structure may be as follows: relative to the sum of the maximum thickness of the piezoelectric element, the maximum thickness of the hair implantation plate, and the minimum hair length of the hair bundle, the ratio of the minimum hair length of the hair bundle becomes greater than 40% and less than 74%.

According to the present invention, a toothbrush having a piezoelectric element on the back side of the brush head can be provided, which can transmit the vibration of the piezoelectric element to the user without attenuating the vibration of the piezoelectric element.

10. D1~D9, D11~D24, E1, E2: Bone conduction toothbrush (toothbrush)

11: Brush structure

12: Brush head

12a: Hair-planted surface

12B: Backend

13: Neck

14: Frame

15: Brush part

16(16a, 16b, 16c, 16d, 16e): Transplantation pores

16f: Bottom surface

16A: The first pore group

16B: Second pore group

17: Hair bundle

17a: Brush hair

17A, 17B: Half hair bundle

18: Piezoelectric components

18b: Bottom surface of piezoelectric element

19: Flatline

22: Body

121: Back

141: Long-sized components

142: Connecting components

143: Hair planting board

143b: The back of the hair-planting board

200: Noise meter

H1, H2: Maximum thickness dimension (thickness)

H3: Hair length (minimum hair length)

H4, H5: thickness

H6: Distance

K: spatial area

K1: First imaginary line

K2: Second imaginary line

L0, L19: Length

M1: Maximum horizontal line distance

M2, M3: Minimum horizontal line distance

N, N1~N4, N(1)~N(5): Transplantation pore array

P1~P3: Spacing (distance)

P4: Spacing

P5, P6, L5: distance

r: Radius

R1: Piezoelectric element area

S1: Total hair transplantation area

S2: Grid arrangement area

X, Y, Z: direction

FIG1 is a diagram showing the overall structure of a toothbrush in one form of the present invention.

FIG2 is a longitudinal cross-sectional view showing the structure of the brush head of a toothbrush in one form of the present invention.

Figure 3 is a diagram showing the arrangement of hair implantation holes formed on the hair implantation surface.

Figure 4 is a diagram showing the arrangement interval of the hair implantation holes formed on the hair implantation surface.

Figure 5 is a diagram showing the horizontal distance between the hair bundles implanted on the hair implantation surface.

Figure 6 is a diagram showing the position of the piezoelectric element built into the brush head.

Figure 7 is a diagram used to illustrate the definition of the grid arrangement of implant pores.

FIG8 is a diagram showing a method for measuring the sound pressure of the brush head 12 of the bone conduction toothbrushes D1 to D3, E1, and E2 of Examples 1 to 3 and Comparative Examples 1 and 2 used in Experiment 1.

FIG. 9A is a diagram showing the specifications of the bone conduction toothbrush D4 of Example 4.

FIG. 9B is a diagram showing the specifications of the bone conduction toothbrush D5 of Example 5.

FIG. 9C is a diagram showing the specifications of the bone conduction toothbrush D6 of Example 6.

FIG. 9D is a diagram showing the specifications of the bone conduction toothbrush D7 of Example 7.

FIG. 10A is a diagram showing the specifications of the bone conduction toothbrush D8.

Figure 10B is a diagram showing the specifications of the bone conduction toothbrush D9.

FIG. 11 is a diagram showing the specifications commonly used in the bone conduction toothbrushes D15 to D24 of Examples 15 to 24.

FIG. 12A is a diagram showing the specifications of the bone conduction toothbrush D15 and the bone conduction toothbrush D16 of Embodiment 15 and Embodiment 16.

FIG. 12B is a diagram showing the specifications of the bone conduction toothbrush D17 and the bone conduction toothbrush D18 of Embodiment 17 and Embodiment 18.

FIG. 12C is a diagram showing the specifications of the bone conduction toothbrush D19 of Example 19.

FIG. 12D is a diagram showing the specifications of the bone conduction toothbrush D20 of Example 20.

FIG. 12E is a diagram showing the specifications of the bone conduction toothbrush D21 of Example 21.

FIG. 12F is a diagram showing the specifications of the bone conduction toothbrush D22 of Example 22.

Figure 12G is a diagram showing the specifications of the bone conduction toothbrush D23 of Example 23.

FIG. 12H is a diagram showing the specifications of the bone conduction toothbrush D24 of Example 24.

[I. Implementation Method]

Below, a bone conduction toothbrush according to one embodiment of the present invention is described.

Furthermore, in the following figures, in order to make it easier to see each component, the scale of the size is sometimes different depending on the component.

FIG. 1 is a diagram showing the overall structure of a bone conduction toothbrush in one form of the present invention. FIG. 2 is a longitudinal sectional view showing the structure of a brush head portion of a toothbrush in one form of the present invention. FIG. 3 is a diagram showing the arrangement of hair implantation holes formed on the hair implantation surface. FIG. 4 is a diagram showing the arrangement interval of hair implantation holes formed on the hair implantation surface. FIG. 5 is a diagram showing the horizontal distance between hair bundles implanted on the hair implantation surface. FIG. 6 is a diagram showing the position of a piezoelectric element built into the brush head portion. Furthermore, in FIG. 3 to FIG. 6, only the structure of the brush head portion 12 is shown, and the neck portion 13 and the like are omitted.

As shown in FIG1 , the bone conduction toothbrush (toothbrush) 10 of the present embodiment is a toothbrush for children's delicate brushing, comprising: a brush structure 11 with a piezoelectric element 18 ( FIG2 ) built therein; and a body 22 connected to the brush structure 11 at one end and supplying current to the piezoelectric element 18. It is preferred that the brush structure 11 is replaceable relative to the body.

Furthermore, in this embodiment, the brush structure 11 and the main body 22 are formed separately, but this is not limited to this. The brush structure 11 can also be formed integrally with the main body 22.

(Entity)

The main body 22 includes a drive control unit for driving the piezoelectric element 18 assembled in the brush structure 11, etc.

(Brush structure)

The brush structure 11 includes: a frame 14 having a brush head 12 and a neck 13, and a brush part 15 provided on the bristle planting surface 12a of the brush head 12.

The brush head portion 12 and the neck portion 13 of the frame 14 are integrally formed into a long shape.

As shown in FIG. 2 , the frame 14 includes: a long-sized component 141, which constitutes the neck 13 and a part of the brush head 12 (the back part 121); an elliptical connecting component 142, which is arranged on one side of the back part 121 constituting the back side of the brush head 12 in the long-sized component 141, forming a ring; and an elliptical hair planting plate 143, which is arranged opposite to the long-sized component 141 via the connecting component 142.

In the frame 14, the long-sized component 141 and the bristle-implanting plate 143 are obtained by injection molding using, for example, a hard resin as a material. The resin forming the long-sized component 141 and the bristle-implanting plate 143 is determined in consideration of the rigidity or mechanical properties required for the brush structure 11 (bone conduction toothbrush 10). For example, a high-hardness resin having a flexural elastic modulus (Japanese Industrial Standards, JIS) K7203) in the range of 1000MPa to 3000MPa can be cited.

Examples of such high-hardness resins include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene dimethylene terephthalate (PCT), polyoxymethylene (POM), polystyrene (PS), acrylonitrile-butadiene-styrene (ABS), cellulose propionate (CP), polyarylate, polycarbonate, acrylonitrile-styrene copolymer (AS), etc. These resins may be used alone or in combination of two or more.

On the other hand, the connecting member 142 plays the role of a wall surrounding the cavity, and existing resin materials can be used.

The brush head 12 has an elliptical hair-planting surface 12a on one side. Specifically, the surface side of the hair-planting plate 143 constituting the brush head 12 (the surface opposite to the connecting member 142 side) is set as the hair-planting surface 12a.

As shown in FIG. 2 and FIG. 3 , a plurality of hair planting holes 16 are formed on the hair planting surface 12a. In the present embodiment, a first hair planting hole group 16A (FIG. 3) is formed in the central area of the length direction (X direction) of the brush head 12 on the hair planting surface 12a, and a pair of second hair planting hole groups 16B (FIG. 4) are formed on both sides of the length direction of the brush head 12 in a manner of sandwiching the first hair planting hole group 16A.

As shown in FIG3 , in the first hair planting pore group 16A, a plurality of hair planting pores 16 are arranged in a grid shape. In this embodiment, for example, as shown in FIG3 , three rows in the length direction (X direction) of the brush head 12 and four rows in the width direction (Y direction), a total of twelve hair planting pores 16 are formed in a grid shape. Furthermore, the number of hair planting pores 16 constituting the first hair planting pore group 16A is not limited thereto.

In each second hair transplantation pore group 16B, as shown in FIG4 , a plurality of hair transplantation pores 16 are arranged in a sawtooth shape. In the present embodiment, for example, in a pair of second hair transplantation pore groups 16B, the centers of the two hair transplantation pores 16 arranged in the width direction in the front row are located between the three hair transplantation pores 16 arranged in the width direction on the side of the first hair transplantation pore group 16A compared to the hair transplantation pores 16, and each second hair transplantation pore group 16B includes five hair transplantation pores 16. Furthermore, the number of hair transplantation pores 16 constituting each second hair transplantation pore group 16B is not limited thereto.

As shown in FIG3 , the hair implantation surface 12a has seven hair implantation hole rows N1 to N4 in the width direction. Among the seven hair implantation hole rows N1 to N4, a pair of hair implantation hole rows N4 located at the outermost side in the width direction of the hair implantation surface 12a respectively have three hair implantation holes 16a arranged at a predetermined interval in the length direction of the hair implantation surface 12a. The three hair implantation holes 16a in each hair implantation hole row N4 constitute a part of the first hair implantation hole group 16A, and are adjacent to each other in the length direction, and are arranged in a straight line in the length direction.

A pair of hair implantation hole rows N3 located on the inner side of a pair of hair implantation hole rows N4 in the width direction respectively have two hair implantation holes 16b formed on both sides thereof in a manner of sandwiching the first hair implantation hole group 16A. The two hair implantation holes 16b constituting each hair implantation hole row N3 constitute a part of the second hair implantation hole group 16B, and are arranged at a predetermined interval in the length direction of the hair implantation surface 12a, and are arranged in a straight line in the length direction.

A pair of hair transplantation pores N2 located on the inner side of a pair of hair transplantation pores N3 in the width direction respectively have three hair transplantation pores 16c and two hair transplantation pores 16d. The three hair transplantation pores 16c are arranged at a predetermined interval in the length direction at the central part of the hair transplantation surface 12a. The two hair transplantation pores 16d are located at the front end and the rear end of the brush head 12.

In each hair transplantation hole row N2, three hair transplantation holes 16c constitute a part of the first hair transplantation hole group 16A, and two hair transplantation holes 16d constitute a part of the second hair transplantation hole group 16B. The three hair transplantation holes 16c and the two hair transplantation holes 16d are adjacent to each other in the length direction and are arranged in a straight line in the length direction.

The hair implantation pore row N1 is located inside the pair of hair implantation pore rows N2 in the width direction and is located in the center of the brush head 12 in the width direction. The hair implantation pore row N1 has two hair implantation pores 16e formed on both sides thereof in a manner of sandwiching the first hair implantation pore group 16A. The two hair implantation pores 16e constitute a part of the second hair implantation pore group 16B, are adjacent in the length direction, and are arranged in a straight line in the length direction.

As shown in FIG. 4 , the distance P1 between the hair implantation pore row N4 and the hair implantation pore row N2 in the width direction of the brush head 12, that is, the distance P1 between the center position of the hair implantation pore 16 of the hair implantation pore row N4 and the center position of the hair implantation pore 16 of each hair implantation pore row N2, is preferably within the range of 2.5 mm to 3.3 mm, and the best is 2.9 mm.

In addition, the distance P2 between a pair of hair implantation pore rows N2 in the width direction of the brush head 12, that is, the distance P2 between the center position of the hair implantation pore 16 of one hair implantation pore row N2 and the center position of the hair implantation pore 16 of another hair implantation pore row N2, is preferably within the range of 2.0 mm to 2.8 mm, and the best is 2.4 mm.

In addition, the distance P3 between the hair implantation pore row N1 and each hair implantation pore row N3 in the width direction of the brush head 12, that is, the distance P3 between the center position of the hair implantation pore 16 of the hair implantation pore row N1 and the center position of the hair implantation pore 16 of each hair implantation pore row N3, is preferably within the range of 2.4mm~3.2mm, and the best is 2.75mm.

In addition, among all the hair implantation holes 16 implanted on the hair implantation surface 12a, the distances P4 between the hair implantation holes 16 arranged in the length direction of the brush head 12 are equal to each other, preferably within the range of 2.4mm~3.2mm, and the best is 2.75mm.

In addition, the distance L4 from the center of the hair-planting hole 16 formed on the hair-planting surface 12a, located at the rear end side of the brush head 12, to the rear end 12B of the brush head 12 is preferably within the range of 2.1mm to 2.9mm, and the best is 2.51mm.

The brush portion 15 includes a plurality of bristle bundles 17 (FIG. 1) implanted in each of a plurality of bristle implantation holes 16 formed on the bristle implantation surface 12a. Each bristle bundle 17 is formed by bundling a predetermined number of bristles of equal length.

The bundled bristles 17a are folded in half, and the flat line 19 (Fig. 5) sandwiched therebetween is driven into the implantation hole 16, thereby implanting each hair bundle 17 on the implantation surface 12a. In this embodiment, as shown in Fig. 5, the flat line 19 is driven into the implantation hole 16 at an angle relative to the length direction of the brush head 12. The directions of the flat lines 19 in all hair bundles 17 are equal and unified.

The inclination angle of the horizontal line 19 is not particularly limited. For example, relative to the length direction of the brush head 12, it is preferably greater than 0 degrees and less than 45 degrees.

The flat line 19 is preferably formed using a material that is difficult to attenuate the vibration of the piezoelectric element 18, such as metal.

In each hair bundle 17, the heights (hereinafter referred to as hair lengths) of one half hair bundle 17A and the other half hair bundle 17B facing each other via the plane line 19 from the hair implantation surface 12a are equal to each other. Therefore, the hair tips of the brush part 15 become flat hair tips as a whole.

Furthermore, the shape of the bristle tip of the brush portion 15 is not limited thereto, and may also have a step difference. For example, the step difference may be formed by changing the hair lengths of the half hair bundles 17A and the half hair bundles 17B in one hair bundle 17. In addition, the hair lengths of the half hair bundles 17A and the half hair bundles 17B in one hair bundle 17 may be equal, but the hair lengths of the multiple hair bundles 17 constituting the brush portion 15 may be different to form a step difference.

The number of bristles 17a constituting the hair bundle 17 can be appropriately set by considering the desired diameter of the hair bundle 17 or the diameter of the hair implantation hole 16, for example, preferably within the range of 30 to 90. More preferably, it is 55 to 75. In addition, in each hair bundle 17, multiple bristles 17a of different thicknesses can be arbitrarily combined for use, considering the feel of use or brushing, cleaning effect, durability, etc.

The cross-sectional shape of the bristle 17a that intersects the length direction is, for example, a circle. Furthermore, it is not limited to this, and the cross-sectional shape may be other than a circle, or may be an ellipse or a polygon.

The hair bundle 17 may be formed of straight hair (non-tapered hair) only, or may be formed of tapered hair, semi-tapered hair, or a combination of the two. From the perspective of improving the effect of removing plaque attached to the tooth surface, the hair bundle 17 is preferably formed of straight hair or semi-tapered hair.

The material of the bristles 17a is not particularly limited, and the materials commonly used for toothbrush bristles can be used. For example, polyamides such as 6-12 nylon and 6-10 nylon, polyesters such as PET, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polyolefins such as PP, olefin elastomers, styrene elastomers, and other resin materials can be listed. These resin materials can be used alone or in combination of two or more.

In the brush head 12 of this embodiment, a piezoelectric element 18 as shown in FIG. 2 and FIG. 6 is built in. Specifically, the piezoelectric element 18 is arranged in a space surrounded by the long-sized component 141, the connecting component 142 and the hair-implanting plate 143, and is arranged in a state where the lower surface 18b of the piezoelectric element 18 contacts the back surface 143b (opposite to the hair-implanting surface 12a) of the hair-implanting plate 143.

As shown in FIG6 , the piezoelectric element 18 is smaller than the hair implantation plate 143 and is arranged in the central part of the hair implantation surface 12a (hair implantation plate 143) when viewed from the hair implantation surface 12a. The piezoelectric element 18 is rectangular in shape with a length along the length direction of the brush head 12 and has a shape that is narrow and tapered in the width direction on the front end side.

The piezoelectric element 18 in this embodiment is vibrated by any sound source data signal transmitted from the main body 22. That is, the sound source data signal is supplied to the piezoelectric element 18 in the form of current, thereby causing the piezoelectric element 18 to vibrate.

In the bone conduction toothbrush 10 of the present embodiment, if the brush head 12 or the brush 15 contacts the biological tissue in the user's oral cavity while the piezoelectric element 18 is driven, the vibration of the piezoelectric element 18 vibrated by the sound source data signal is transmitted to the brush 15 via the frame 14 of the brush head 12. If the brush head 12 or the brush 15 contacts the biological tissue in the child's oral cavity while vibrating, the vibration of the brush head 12 or the brush 15 is transmitted to the child's bones via the biological tissue only during the period when the brush head 12 or the brush 15 contacts the biological tissue, and the vibration is recognized by the child as sound.

Thus, according to the bone conduction toothbrush 10 of this embodiment, the piezoelectric element 18 that converts the sound source data signal (electronic signal) into vibration (sound) is built into the brush head 12, so that when the brush head 12 or the brush part 15 contacts the teeth or gums, the vibration is transmitted to the inner ear through the teeth or gums, and the sound (such as music) can be enjoyed only during brushing.

In the bone conduction toothbrush 10 of this embodiment, when the vibration of the piezoelectric element 18 vibrating by the sound source data signal contacts the teeth of the child through the brush portion 15, the vibration of the piezoelectric element 18 is transmitted to the teeth, etc., and the vibration is directly transmitted to the inner ear, thereby allowing the child to recognize the vibration as sound. Therefore, the child will not be affected by the surrounding noise heard through the eardrum or the child's own voice, etc., and can recognize the sound from the toothbrush 10 through bone conduction. In this way, the burden of delicate brushing on parents can be reduced, and the child himself will not hate delicate brushing and can enjoy brushing itself.

In this embodiment, when a sound source of 1000 Hz or more and 7000 Hz or less flows into the piezoelectric element, the vibration level of the brush portion is preferably 50 dB SPL or more and 70 dB SPL or less, and more preferably 55 dB SPL or more and 65 dB SPL or less.

In this frequency range (sound source), if the vibration level of the brush part 15 is set to be above 45dB SPL and below 75dB SPL, the volume of the sound perceived by children can be made appropriate.

Here, when the vibration level of the brush part 15 is below 45dB SPL, the vibration level of the piezoelectric element 18 is small, and it is difficult for children to recognize it as sound. On the other hand, when the vibration level of the brush part 15 is above 75dB SPL, the vibration level of the brush part 15 is large, and the size of the sound recognized by the child becomes too large. Therefore, when the vibration level is greater than 75dB SPL, the size of the sound recognized by bone conduction also becomes very large, and it becomes a level that is felt to be harmful to the user.

Therefore, the vibration level generated by the bone conduction toothbrush 10 is set within the above range, so that when the bone conduction toothbrush 10 hits the teeth, the vibration transmitted by the bone conduction toothbrush 10 can be perceived as sound, and the harmfulness caused by excessive sound pressure can not be felt.

The main components of the brush structure 11 are described in detail below.

As shown in FIG2 , the piezoelectric element 18 is arranged in a state of contacting the back surface 143b of the hair-implanting plate 143, but the ratio A1 of the total area of the plurality of hair-implanting holes 16 arranged in the hair-implanting plate 143 (hair-implanting surface 12a) and overlapping the piezoelectric element 18 in the piezoelectric element region R1 ( FIG6 ) when viewed from above is preferably 30% or more, and more preferably 40% or more, relative to the total area of all hair-implanting holes 16 arranged in the hair-implanting plate 143 (hair-implanting surface 12a).

The larger the total area of all the hair-implanting holes 16 provided in the piezoelectric element region R1, the larger the vibration of the piezoelectric element 18 transmitted to the hair bundle 17 provided in the hair-implanting hole 16. Therefore, in order to make the size of the sound recognizable by children become the desired size, it is preferable to set the ratio A1 of the total area of the plurality of hair-implanting holes 16 in the piezoelectric element region R1 within the above range.

When the ratio A1 of the total area of the plurality of hair-implanting holes 16 in the piezoelectric element region R1 relative to the total area of all hair-implanting holes 16 provided on the hair-implanting surface 12a is less than 30%, the number of hair bundles 17 that efficiently transmit the vibration of the piezoelectric element 18 decreases relative to all hair-implanting holes 16 provided on the hair-implanting surface 12a. Therefore, the vibration of the piezoelectric element 18 cannot be fully transmitted to the child.

In addition, relative to the area of the piezoelectric element region R1, the ratio A2 of the total area of the plurality of hair implantation holes 16 present in the piezoelectric element region R1 is preferably greater than 23%, and more preferably greater than 33%. Furthermore, if the strength of the hair implantation plate 143 is considered, the upper limit is preferably less than 60%.

The larger the ratio A2 of the total area of all hair implantation holes 16 in the piezoelectric element region R1 relative to the area of the piezoelectric element region R1, the more efficiently the vibration of the piezoelectric element 18 can be transmitted to the child.

Here, when the ratio A2 of the total area of all hair implantation holes 16 existing in the piezoelectric element region R1 relative to the area of the piezoelectric element region R1 is less than 23%, the number of hair implantation holes 16 existing in the piezoelectric element region R1 relative to the area of the piezoelectric element region R1 decreases, so the vibration of the piezoelectric element 18 cannot be efficiently transmitted to the child.

In addition, in this embodiment, as shown in FIG. 2 , the distance H6 from the lower surface 18b of the piezoelectric element 18 that contacts the back surface 143b of the hair implantation plate 143 to the bottom surface (hole bottom) 16f of the hair implantation hole 16 is preferably greater than 0.4 mm and less than 1.6 mm. More preferably, it is greater than 0.4 mm and less than 1.0 mm.

As a result, the distance between the piezoelectric element 18 and the bottom surface 16f of the hair implantation hole 16 is shortened, so the vibration of the piezoelectric element 18 can be transmitted to each hair bundle 17 without attenuation.

Here, when the distance H6 exceeds 1.6 mm, the distance between the piezoelectric element 18 and the bottom surface 16f of the hair implantation hole 16 becomes longer, so the vibration of the piezoelectric element 18 is attenuated and not efficiently transmitted to each hair bundle 17.

On the other hand, the reason for setting the distance H6 to be greater than 0.4 mm is that the minimum thickness necessary must be ensured in order to maintain the strength of the bone conduction toothbrush 10.

Therefore, it is better to set the distance H6 within the range. In this embodiment, the distance H6 is set to 0.5mm.

As shown in Figures 3 and 5, the hair bundle 17 with multiple bristles 17a bundled together is implanted in the hair implantation hole 16 using a metal flat wire 19, but it is preferred that among all the hair bundles 17 implanted on the hair implantation surface 12a, there are at least three rows of hair bundles 17 that meet the following two conditions 1 and 2.

Condition 1: The shortest distance between the flat lines 19 punched into each of the multiple hair-planting holes 16 arranged in the length direction of the brush head 12 (hereinafter referred to as the distance between flat lines) is 0.25 mm or more and 1.5 mm or less. Preferably, it is 0.25 mm or more and 1.0 mm or less.

Condition 2: The ratio of the sum of the lengths of the plurality of adjacent horizontal lines 19 in the length direction in each row N1 to N4 to the length of the implanted hair region in the length direction is 53% or more and 94% or less. Preferably, it is 60% or more and 80% or less.

In this embodiment, the length of the flat line 19 is preferably 1.95mm~2.45mm, and the best is 2.25mm.

Specifically, in this embodiment, among the arrangements of all hair bundles 17 implanted on the hair implantation surface 12a, the arrangements of hair bundles 17 that meet the above conditions 1 and 2 are as shown in FIG3 and FIG4, which are the hair implantation hole row N2 located in the center of the width direction and the pair of hair implantation hole rows N4 located at the outermost sides of the width direction.

For example, when the length L0 (Figure 5) of the hair transplantation area in the longitudinal direction of the hair transplantation hole row N2 is 18.8mm, the length L19 of the flat line 19 is 2.25mm, the maximum flat line distance M1 (Figure 5) in each hair transplantation hole row N2 is 3.26mm, and the minimum flat line distance M2 (Figure 5) is 0.61mm, relative to the length L0 of the hair transplantation area in the longitudinal direction of the hair transplantation hole row N2, the ratio of the sum of the lengths of the multiple flat lines 19 adjacent to each other in the longitudinal direction in the hair transplantation hole row N2 is 59.8%, which meets the above conditions 1 and 2 and can be regarded as a better specification.

In addition, for example, when the minimum distance M3 between the flat lines in each hair-implanting hole row N4 is 0.61 mm, the ratio of the sum of the lengths of the multiple flat lines 19 adjacent to each other in the length direction to the length of the hair-implanting surface 12a in the length direction is 53.6%, which can be regarded as a better specification.

In this embodiment, the shortest distance of all adjacent horizontal lines 19 in the length direction is preferably within the range of 0.25 mm to 1.5 mm, and is even better if it is greater than 0.25 mm and less than 1.0 mm.

As a medium for transmitting the vibration of the piezoelectric element 18 built into the brush head 12, the metal constituting the flat wire 19 is the most suitable material. The metal has high hardness, so the vibration from the piezoelectric element 18 is difficult to attenuate inside the metal. Therefore, the more flat wires 19 are driven in the length direction of the bone conduction toothbrush 10 (the hair implantation surface 12a), the higher the vibration efficiency in the hair implantation plate 143 and each hair bundle 17.

In addition, in this embodiment, as shown in FIG. 3, at least a portion of the multiple hair implantation holes 16 formed on the hair implantation surface 12a are arranged in a grid shape. Here, when the area where all the hair implantation holes 16 exist in the hair implantation surface 12a is set as the total hair implantation area S1, and the area where the first hair implantation hole group 16A in the center of the hair implantation surface 12a and multiple hair implantation holes 16 are arranged in a grid is set as the grid arrangement area S2, in this embodiment, the ratio of the area of the grid arrangement area S2 to the area of the total hair implantation area S1 is preferably 20% or more and 100% or less, and more preferably 50% or more and 100% or less.

The total hair transplantation area S1 is an area surrounded by the first imaginary line K1, which connects the outer edges of multiple hair transplantation holes 16 located on the outermost side of all hair transplantation holes 16 on the hair transplantation surface 12a with the shortest distance. The grid arrangement area S2 is an area surrounded by the second imaginary line K2, which connects multiple outer hair transplantation holes 16 located on the outermost side of the first hair transplantation hole group 16A with the shortest distance.

Refer to Figures 3 and 7 to define the grid arrangement. Figure 7 is a diagram showing the spacing of the implant holes.

In this embodiment, the so-called grid arrangement (FIG. 3) refers to the following arrangement: as shown in FIG. 7, when the radius of the implantation hole 16 is set to r, the distance P5 in the width direction of the brush head 12 between the centers of the adjacent implantation holes 16 in the length direction of the brush head 12 is less than 1/2r, and the distance P6 in the length direction of the brush head 12 between the centers of the adjacent implantation holes 16 in the width direction of the brush head 12 becomes less than 1/2r.

In this embodiment, for example, when the area of the total hair implantation area S1 (FIG. 3) is 1.43 ^cm2 and the area of the grid arrangement area S2 is 0.72 ^cm2 , the area ratio of the grid arrangement area S2 (FIG. 3) to the area of the total hair implantation area S1 is 50.3%, which is a better specification.

Thus, the more uniformly all the hair implantation holes 16 formed on the hair implantation surface 12a are expanded across the entire hair implantation surface 12a, the more the attenuation of the vibration of the piezoelectric element 18 can be suppressed in the hair implantation plate 143. That is, in the entire hair implantation surface 12a, the more uniformly all the hair implantation holes 16 (hair bundles 17) are arranged without becoming partially sparse and dense, the more efficiently the vibration of the piezoelectric element 18 can be transmitted to the child through the brush part 15, etc.

In order to efficiently transmit the vibration of the piezoelectric element 18 to the hair implantation plate 143, among all the hair implantation holes 16 formed in the hair implantation plate 143, the arrangement of the hair implantation holes 16 in the area (piezoelectric element area R1) overlapping with the piezoelectric element 18 when viewed from above is the most important. The arrangement of the hair implantation holes 16 in the piezoelectric element area R1 is set to a grid shape, thereby improving the vibration efficiency of the piezoelectric element 18, so the ratio of the area of the grid arrangement area S2 relative to the area of the total hair implantation area S1 is preferably ensured to be more than 20%. Furthermore, the larger the ratio of the area of the grid arrangement area S2, the more uniformly the vibration of the piezoelectric element 18 can be transmitted to the brush part 15 (each hair bundle 17).

For example, when the area of the total hair implantation area S1 (FIG. 3) is 1.43 ^cm2 and the area of the grid arrangement area S2 is 0.72 ^cm2 , the area of the grid arrangement area S2 (FIG. 3) is 50.3% relative to the area of the total hair implantation area S1. At this time, the area of the grid arrangement area S2 in the piezoelectric element area R1 (FIG. 6) is 0.298 ^cm2 , which is 20.8% relative to the area of the total hair implantation area S1. Thus, if the area of the grid arrangement area S2 in the piezoelectric element area R1 is 20% or more relative to the area of the total hair implantation area S1, it becomes a better specification.

In addition, in this embodiment, relative to the area of the total hair-implanting region S1 surrounded by the first imaginary line K1 ( FIG. 3 ), the total number of all bristles 17a implanted on the hair-implanting surface 12a is preferably greater than 600/cm ² and less than 2800/cm ² .

When the total number of all bristles 17a implanted on the implanted surface 12a is less than 600 bristles/ ^cm2 relative to the area of the total implanted area S1 surrounded by the first imaginary line K1, the number of bristles 17a decreases, and the medium for transmitting the vibration of the piezoelectric element 18 decreases, so that the vibration of the piezoelectric element 18 is difficult to be transmitted to the teeth.

In addition, when the total number of all bristles 17a implanted on the implanted surface 12a is greater than 2800 bristles/ ^cm2 relative to the area of the total implanted area S1 surrounded by the first imaginary line K1, the thickness of each bristle 17a becomes too fine and the softness becomes excessively high, so the vibration of the piezoelectric element 18 is attenuated within each bristle 17a and does not transmit sufficient vibration to the teeth.

Therefore, it is preferable to set the total number of all bristles 17a implanted on the bristle implantation surface 12a relative to the area of the total bristle implantation area S1 surrounded by the first imaginary line K1 within the said range.

When setting the optimal total number of roots, the following two factors are considered to improve the vibration transmission capability.

The first factor is that by planting more hair bundles 17 on the hair planting surface 12a, the transmission medium that transmits the vibration of the piezoelectric element 18 to the child's teeth increases, thereby further improving the vibration efficiency of the piezoelectric element 18. Strictly speaking, the larger the ratio of the total area of all hair planting holes 16 per unit area of the total hair planting area S1, the higher the vibration efficiency of the piezoelectric element 18. As a result, the more the number of bristles 17a in the total hair planting area S1, the higher the vibration efficiency.

The second factor is that the bending state of the bristles 17a during brushing varies according to the hardness of the material. The harder and harder the bristles 17a are to bend, the higher the vibration efficiency. Strictly speaking, the larger and thicker the diameter of the bristles 17a, the higher the vibration efficiency.

First, the first factor is related to the setting of the upper limit and lower limit of the total area of all hair implantation holes 16 existing in the total hair implantation area S1.

When the "area of the total hair implantation region S1" is equal to the "total area of all hair implantation holes 16 present in the total hair implantation region S1", the vibration efficiency of the piezoelectric element 18 can be maximized. This is equivalent to the so-called single-bundle structure. Therefore, in this embodiment, the upper limit of the total area of all hair implantation holes 16 is 1.43 ^cm2 , which is equal to the area of the total hair implantation region S1.

On the other hand, the lower limit of the total area of all the hair-implanting holes 16 becomes the total hole area when each hair-implanting hole 16 is at the minimum diameter. For example, when the minimum diameter of the hair-implanting hole 16 is 1.2 mm and the number of all the hair-implanting holes 16 is 22, the total area of the hair-implanting holes 16 becomes 0.249 cm ² . In this embodiment, it is preferred that 0.249 cm ² becomes the lower limit of the total area of the hair-implanting holes 16.

Secondly, the second factor is related to the setting of the upper and lower limits of the bristle diameter of the bristles 17a.

In this embodiment, the upper limit of the bristle diameter that can maximize the vibration efficiency of the piezoelectric element 18 is preferably 10 mil (diameter is 0.254 mm), and the lower limit is preferably 4 mil (diameter is 0.1016 mm). As a better range, considering the ease of hearing the sound and the feel of using the bone conduction toothbrush 10, it is preferably 7 mil~5 mil, and more preferably 6 mil~5 mil.

If the upper and lower limits of the two factors are considered, the upper and lower limits of the total number of bristles 17a relative to the area of the total bristle implantation area S1 (the area of the lower surface 18b of the piezoelectric element 18) can be obtained by the following calculation formulas 1 and 2.

<Calculation formula 1>

(Total area of implanted pores) × (PF: filling factor) / (cross-sectional area of bristles 17a) = total number of bristles 17a

<Calculation 2>

(Total number of bristles 17a)/(Total area of the bristle-planting region S1: 1.43 ^cm2 ) = Ratio of the total number of bristles 17a to the area of the total bristle-planting region S1

The upper limit of the ratio A of the total number of bristles 17a to the area of the total bristle implantation area S1 can be calculated based on the upper limit of the total area of the bristle implantation holes and the lower limit of the bristle diameter.

If the calculation formula 1 is used for calculation, the upper limit value of the ratio A is as follows.

1.43cm ² ×PF: 90%/(0.1016×0.1016×3.14×10 ^-2 )cm ² = 3970

3970 strands/ ^1.43cm2 = 2776 strands/ ^cm2

The lower limit of the ratio A can be calculated based on the lower limit of the total area of the implanted pores and the upper limit of the bristle diameter.

If the calculation formula 1 is used for calculation, the lower limit value of the ratio A is as follows.

0.249cm ² ×PF: 70%/(0.254×0.254×3.14×10 ^-2 )cm ² = 860

860 strands/ ^1.43cm2 = 2776 strands/ ^cm2 = 602 strands/ ^cm2

Therefore, it is preferable to set the ratio A in the range of 600 strands/cm ² to 2800 strands/cm ² .

Furthermore, in this embodiment, the ratio A is 2030 strands/cm ² .

In addition, in the present embodiment, as the bristles 17a, bristles having forked hairs with the tips forked into a plurality of hairs may also be used. The number of forked hairs is not particularly limited, and may be two to four or more. When using bristles having such forked hairs, the total number of forked hairs of all bristles 17a implanted in the area S1 is preferably 600 or ^more and 11200 or ^less , relative to the area of the total implanted hair area S1 surrounded by the first imaginary line K1.

In this embodiment, the number of forked hairs in one bristle 17a is preferably four.

Therefore, it is preferable to set the upper limit value (11200/ ^cm2 ) to a value that quadruples the upper limit value (2800/ ^cm2 ) of the total number of bristles 17a in the total bristle implantation area S1.

The more bristles (branched hairs) there are on the front end of each bristle 17a, the larger the contact area of the brush portion 15 with the child's teeth becomes, so the vibration of the piezoelectric element 18 can be efficiently transmitted to the teeth.

In addition, in this embodiment, as shown in FIG. 2, the thickness of the maximum thickness dimension H1 of the piezoelectric element 18 and the maximum thickness dimension H2 of the hair-implanting plate 143 is preferably greater than 3.4 mm and less than 7.0 mm, and more preferably greater than 3.4 mm and less than 6.0 mm. If the thickness of the maximum thickness dimension H1 of the piezoelectric element 18 and the maximum thickness dimension H2 of the hair-implanting plate 143 is less than 3.4 mm, the minimum strength of the toothbrush 10 cannot be maintained. In addition, if the thickness of the maximum thickness dimension H1 of the piezoelectric element 18 and the maximum thickness dimension H2 of the hair-implanting plate 143 exceeds 6.0 mm, the operability in the oral cavity deteriorates.

Here, the larger the maximum thickness dimension H1 of the piezoelectric element 18, the higher the vibration level of the brush portion 15. In addition, the larger the maximum thickness dimension H2 of the bristle plate 143, the more hard material constituting the bristle plate 143 increases, so the vibration level of the brush portion 15 becomes higher. However, the larger the maximum thickness dimension H1 of the piezoelectric element 18 and the maximum thickness dimension H2 of the bristle plate 143, the greater the thickness of the brush head portion 12, so the operability of the toothbrush 10 in the oral cavity decreases.

Therefore, the thickness of the brush head 12 is set within the above range, which is the sum of the maximum thickness dimension H1 of the piezoelectric element 18 and the maximum thickness dimension H2 of the bristle implantation plate 143. Thereby, a bone conduction toothbrush 10 can be realized that ensures the vibration level transmitted from the piezoelectric element 18 within a problem-free range and does not damage the operability of the brush head 12 in the oral cavity.

The thickness H5 of the entire brush head side including the brush head portion 12 and the bristle portion 15 in this embodiment is 15 mm. In the case of a thickness greater than this, the thickness of the brush head of the bone conduction toothbrush 10 is too thick, and the operability in the oral cavity is reduced. Therefore, it is preferable to set the upper limit of the thickness H5 of the entire brush head side to 15 mm. Here, the thickness H4 of the space area K (Figure 2) existing inside the brush head portion 12 is not considered, but the toothbrush 10 including the thickness H1 of the piezoelectric element 18, the thickness H2 of the bristle plate 143, and the bristle length H3 is considered.

Therefore, the upper limit of the thickness of the piezoelectric element 18, the thickness H1 of the hair implantation plate 143, and the hair length H3 is the upper limit of the thickness H5 of the entire brush head side (15mm).

Here, the upper limit value of the thickness H1 of the piezoelectric element 18 is not particularly limited. The size of the piezoelectric element 18 is proportional to the vibration level, so the larger the size of the piezoelectric element 18, the larger the vibration level becomes. Therefore, the upper limit value of the thickness H1 is not particularly set. On the other hand, the lower limit value of the thickness H1 of the piezoelectric element 18 is preferably 0.9 mm.

The upper limit of the thickness H2 of the implanting plate 143 is not particularly limited. As the amount of hard resin in the implanting plate 143 increases, the vibration level also increases. Therefore, the upper limit is not particularly set. On the other hand, the lower limit of the thickness H2 of the implanting plate 143 is 2.5 mm, which can ensure the minimum strength.

The upper limit of the hair length H3 of the hair bundle 17 (bristle 17a) is preferably 11 mm.

If the hair length H3 exceeds 11 mm, the vibration of the piezoelectric element 18 is greatly attenuated in the bristles 17a, and the vibration is not transmitted to the tip of the bristles 17a.

The lower limit of the hair length is preferably 6 mm. If the hair length is less than 6 mm, the feel of the bone conduction toothbrush 10 will deteriorate.

In addition, in this embodiment, as shown in FIG. 2 , the ratio of the minimum hair length H3 of the hair bundle 17 is preferably 40% or more and 74% or less relative to the sum of the maximum thickness dimension H1 of the piezoelectric element 18, the maximum thickness dimension H2 of the hair implantation plate 143, and the minimum hair length H3 of the hair bundle 17. If the ratio of the minimum hair length H3 of the hair bundle 17 is less than 40%, the touch feeling of the hair bundle during brushing becomes worse. In addition, if the ratio of the minimum hair length H3 of the hair bundle 17 exceeds 74%, the operability in the oral cavity becomes worse.

Here, when the ratio of the minimum hair length H3 of the hair bundle 17 to the sum of the maximum thickness dimension H1 of the piezoelectric element 18, the maximum thickness dimension H2 of the hair implantation plate 143, and the minimum hair length H3 of the hair bundle 17 is less than 40%, the hair length of the bristles 17a that attenuate the vibration of the piezoelectric element 18 becomes shorter, so the distance from the piezoelectric element 18 to the child's teeth becomes shorter, and the vibration transmission efficiency in the piezoelectric element 18 is improved. However, since the hair length of the brush part 15 becomes shorter, the usability of the bone conduction toothbrush 10 is damaged.

In addition, when the ratio of the minimum hair length H3 of the hair bundle 17 to the sum of the maximum thickness dimension H1 of the piezoelectric element 18, the maximum thickness dimension H2 of the hair implantation plate 143, and the minimum hair length H3 of the hair bundle 17 is greater than 74%, the hair length of the bristles 17a becomes longer, so the vibration transmission efficiency of the piezoelectric element 18 decreases, and the vibration of the piezoelectric element 18 is not fully transmitted to the teeth of the child.

Therefore, the ratio of the minimum hair length H3 of the hair bundle 17 to the sum of the maximum thickness dimension H1 of the piezoelectric element 18, the maximum thickness dimension H2 of the hair implantation plate 143, and the minimum hair length H3 of the hair bundle 17 is set within the above range, so as to ensure the vibration level transmitted from the piezoelectric element 18 and not damage the bone conduction toothbrush 10 of the use feeling. In this embodiment, the minimum hair length H3 of the hair bundle 17 is preferably 6mm~10mm.

By optimizing the materials of the frame 14 and the bristles 17a or the diameter and arrangement of the implant holes 16 as described above, the vibration efficiency of the piezoelectric element 18 can be fully improved during brushing, until the child can reliably recognize the "sound" through the bone conduction toothbrush 10.

In addition, generally speaking, many toothbrushes are equipped with a piezoelectric element 18 to improve the cleaning effect of teeth, but in this embodiment, the bone conduction toothbrush 10 includes a piezoelectric element 18 as a tool for delivering music to children during fine brushing.

[Implementation example]

The invention of this application is described in detail below using examples, but the invention is not limited to the following description.

<<Experiment 1>>

FIG8 is a diagram showing a method for measuring the sound pressure of the brush head 12 of the bone conduction toothbrushes D1 to D3, E1, and E2 of Examples 1 to 3 and Comparative Examples 1 and 2 used in Experiment 1.

In Experiment 1, the relationship between sound pressure and the degree of audible sound (user experience) was investigated.

(Purpose)

The goal is to determine the sound pressure values when the sound from the toothbrush is inaudible and when the sound is loud.

(Preparation of bone conduction toothbrushes of Example 1 to Example 3, Comparative Example 1, and Comparative Example 2)

Table 1 shows the specifications of the bone conduction toothbrushes D1 to D3 of Examples 1 to 3.

According to the specifications shown in Table 1, bone conduction toothbrushes D1 to D3 of Examples 1 to 3 based on the above-mentioned embodiment are manufactured. The thickness of the piezoelectric element 18 and the length of the bristles 17a of the bone conduction toothbrushes D1 to D3 of each embodiment are different. In addition, bone conduction toothbrushes E1 and E2 of Comparative Example 1 and Comparative Example 2 are manufactured according to the specifications shown in Table 1. In the toothbrushes E1 and E2 of the comparative examples, the thickness of the piezoelectric element 18 and the length of the bristles 17a are also different.

Thus, for each specification of the five bone conduction toothbrushes D1~D3, E1, and E2, the thickness and hair length of the piezoelectric element 18 are different, and the other specifications are set to be the same.

(Common part of the specification)

Area of piezoelectric element 18: 0.685 cm ²

Total implant area S1: 1.43cm ²

Diameter of implant hole 16: 1.75mm

The distance from the lower surface 18b of the piezoelectric element 18 to the bottom surface 16f of the implant hole 16: 0.6mm

The depth of implant hole 16: 2.5mm

Diameter of bristle 17a: 5mil

Number of bristles 17a per hair transplant hole 16: 2122/ ^cm2

[Evaluation method]

1) Sound pressure (dB SPL)

First, a sound source data signal of 1000Hz, 3000Hz, and 7000Hz is sent from a personal computer to each toothbrush D1~D3, E1, and E2 equipped with a piezoelectric element 18 to vibrate the piezoelectric element 18. If the vibration of the piezoelectric element 18 is transmitted to the hair-planting plate 143 and each hair bundle 17, the vibration of the hair tips of the toothbrushes D1~D3, E1, and E2 causes air vibration, so the vibration level is measured using a noise meter 200. Here, the noise meter 200 is configured at a position slightly separated from the front end of each toothbrush D1~D3, E1, and E2 for measurement. Specifically, as shown in FIG8, the distance L5 from the front end of each toothbrush D1~D3, E1, and E2 to the noise meter 200 is set to 5mm.

2) Evaluation of the user experience related to the ease of hearing of the sound (points)

As mentioned above, the sound source data signals of 1000Hz, 3000Hz, and 7000Hz were sent to the piezoelectric elements of each toothbrush D1~D3, E1, and E2. After brushing teeth for 3 minutes, a questionnaire survey was conducted on a panel of 10 experts.

Regarding the questionnaire survey, "Ease of hearing the sound" was evaluated in five stages. Here, the average score of the 10-person panel was used as the evaluation result.

(Evaluation criteria)

5 points: noisy

4 points: Can be heard clearly

3 points: audible

2 points: Slightly audible

1 point: Can’t hear

Specifically, an average score of 4.0 or less and 2.0 or more is considered "OK", and an average score greater than 4.0 or less than 2.0 is considered "NG".

<Conclusion>

As shown in Table 1, in toothbrushes D1 to D3 of Examples 1 to 3, each sound pressure value becomes 45dB SPL to 79dB SPL, and the evaluation score is 2.0 points or more and 4.0 points or less. Therefore, toothbrushes D1 to D3 of Examples 1 to 3 received the following evaluation: the sound emitted from the toothbrush can be heard reliably, and the sound can be heard at an appropriate level.

On the other hand, the toothbrush rated as the least audible was toothbrush E1 in Comparative Example 1, which had a rating of less than 2.0, and its lowest sound pressure value was 40dB SPL. In addition, the toothbrush rated as the noisiest was toothbrush E2, which had a rating of more than 4.0, and its highest sound pressure value was 84dB SPL.

<<Experiment 2>>

In Experiment 2, four experiments (2-1) to (2-4) were conducted to investigate the relationship between the specifications of each bone conduction toothbrush and the audibility of the sound (user experience).

(Purpose)

Research on the specifications of the bone conduction toothbrush 10 that makes it easy to hear the sound.

[Evaluation method]

1) User experience evaluation

The sound source data signals of 1000Hz~7000Hz were sent to the piezoelectric element of each bone conduction toothbrush made as a sample, and after brushing teeth for 3 minutes, a questionnaire survey was conducted on a panel of 10 experts.

Regarding the questionnaire survey, "Ease of hearing the sound" was evaluated in five stages. Here, the average score of the 10-person panel was used as the evaluation result.

(Evaluation criteria)

5 points: noisy

4 points: Can be heard clearly

3 points: audible

2 points: Slightly audible

1 point: Can’t hear

Specifically, toothbrushes with an average score of 4.0 to 3.0 were rated as "◎", and toothbrushes with an average score of 2.0 to less than 3.0 were rated as "○".

2) Strength as a toothbrush

Brush your teeth for 3 minutes 3 times a day and observe the grafted surface 90 days later. If no whitening or cracks are found, it is considered acceptable (OK), and if whitening or cracks are found, it is considered unacceptable (NG).

<Experiment 2-1>

(Manufacturing of bone conduction toothbrushes D4 to D7 of Examples 4 to 7)

Table 2 shows the manufacturing specifications of the bone conduction toothbrushes D4 to D7 of Examples 4 to 7.

In experiment (2-1), according to the specifications shown in Table 2, bone conduction toothbrushes D4 to D7 of Examples 4 to 7 based on the above-mentioned embodiment were produced, and the ease of hearing of the sound was evaluated. FIG. 9A is a diagram showing the specifications of the bone conduction toothbrush D4 of Example 4. FIG. 9B is a diagram showing the specifications of the bone conduction toothbrush D5 of Example 5. FIG. 9C is a diagram showing the specifications of the bone conduction toothbrush D6 of Example 6. FIG. 9D is a diagram showing the specifications of the bone conduction toothbrush D7 of Example 7.

Regarding the specifications of the four toothbrushes D4 to D7, the size and configuration of the piezoelectric element 18 are different. That is, the ratio (%) of the total area of the multiple hair-planting holes 16 existing in the piezoelectric element area R1 to the total area of all hair-planting holes 16 existing on the hair-planting surface 12a is different. The other specifications are set to be the same.

(Common part of the specification)

Thickness of piezoelectric element 18: 0.9mm

Diameter of implant hole 16: 1.75mm

Distance from the lower surface 18b of the piezoelectric element 18 to the bottom surface 16f of the implant hole 16: 1.6mm

The depth of implant hole 16: 2.5mm

Bristle diameter of bristle 17a: 5mil

Number of bristles 17a per hole (total number of bristles per bundle): 2122/ ^cm2

Bristle length 17a: 7mm

Hole arrangement: The same hole arrangement as the above-mentioned implementation method (refer to Figure 9A to Figure 9D)

<Results>

As shown in Table 2, a panel of 10 experts evaluated the "ease of hearing the sound" for the bone conduction toothbrushes D4 to D7 of Examples 4 to 7. It can be seen that when the total area of the implanted hair pores 16 in the piezoelectric element region R1 becomes more than 30% of the total area of all the implanted hair pores 16 in the entire brush head, the score related to the ease of hearing the music becomes higher.

<Experiment 2-2>

Table 3 shows the specifications of the bone conduction toothbrush D5, bone conduction toothbrush D8, and bone conduction toothbrush D9 of Example 5, Example 8, and Example 9.

In experiment (2-2), three bone conduction toothbrushes D5, D8, and D9 were manufactured according to the specifications shown in Table 3, and the ease of hearing of the sound was evaluated.

(Manufacturing of bone conduction toothbrush D5 of Example 5 and bone conduction toothbrush D8 and bone conduction toothbrush D9 of Examples 8 and 9)

FIG. 10A is a diagram showing the specifications of the bone conduction toothbrush D8. FIG. 10B is a diagram showing the specifications of the bone conduction toothbrush D9. For the specifications of the bone conduction toothbrush D5 of Example 5, refer to FIG. 9B.

Regarding the specifications of the three bone conduction toothbrushes D5, D8, and D9, the arrangement of the implantation holes 16 and the diameter of the implantation holes 16 are different. The other specifications are set to be the same.

(Common part of the specification)

Piezoelectric element area R1: ^0.47cm2

Thickness of piezoelectric element 18: 0.9mm

Distance from the lower surface 18b of the piezoelectric element 18 to the bottom surface 16f of the implant hole 16: 1.6mm

The depth of implant hole 16: 2.5mm

Bristle diameter of bristle 17a: 5mil

Number of bristles 17a per hole (total number of bristles per bundle): 2122/ ^cm2

Bristle length 17a: 7mm

<Results>

As shown in Table 3, a panel of 10 experts evaluated the "ease of hearing the sound" for toothbrushes D5, D8, and D9 of Examples 5, 8, and 9. It can be seen that when the ratio of the total area of the plurality of hair-implanting holes 16 in the piezoelectric element region R1 overlapping the lower surface 18b of the piezoelectric element 18 in the hair-implanting plate 143 to the total area of all hair-implanting holes 16 provided in the hair-implanting plate 143 becomes 23% or more, the score related to the ease of hearing the music becomes higher.

<Experiment 2-3>

Table 4 shows the specifications of the bone conduction toothbrush D5, bone conduction toothbrush D11 to bone conduction toothbrush D14 of Example 5, Example 11 to Example 14.

In experiment (2-3), five bone conduction toothbrushes D5, D11~D14 were manufactured according to the specifications shown in Table 4, and the audibility of the sound was evaluated.

(Preparation of bone conduction toothbrushes D5, D11, and D14 of Examples 5, 11, and 14)

Regarding the specifications of the five bone conduction toothbrushes D5, D11 to D14, the distance from the lower surface 18b of the piezoelectric element 18 to the bottom surface 16f of the hair implantation hole 16 is different. The other specifications of the bone conduction toothbrushes of Examples 11 to 14 are the same as the specifications of the bone conduction toothbrush D5 of Example 5 shown in FIG. 9B, so it is appropriate to refer to FIG. 9B.

(Common part of the specification)

Area of the lower surface 18b of the piezoelectric element 18 (piezoelectric element region R1): 0.47 cm ²

Thickness of piezoelectric element 18: 0.9mm

Diameter of implant hole 16: 1.75mm

The depth of implant hole 16: 2.5mm

Bristle diameter of bristle 17a: 5mil

Number of bristles 17a per hole (total number of bristles per bundle): 2122/ ^cm2

Bristle length 17a: 7mm

Hole arrangement: refer to Figure 9B

Position of piezoelectric element 18: Refer to Figure 9B

<Results>

As shown in Table 4, the results of the evaluation of "Ease of hearing the sound" show that in the case of a toothbrush with a distance H6 (see Figure 2) from the lower surface 18b of the piezoelectric element 18 to the bottom surface 16f of the implant hole 16 being less than 1.6 mm, the score related to the ease of hearing the music becomes higher. In addition, in order to maintain the strength as a toothbrush, the distance H6 must be greater than 0.4 mm.

<Experiment 2-4>

Table 5 shows the specifications of the bone conduction toothbrushes D15 to D24 of Examples 15 to 24.

In experiment (2-4), ten bone conduction toothbrushes D15~D24 were manufactured according to the specifications shown in Table 5, and the ease of hearing of the sound was evaluated.

FIG. 11 is a diagram showing the specifications commonly used in the bone conduction toothbrushes D15 to 24 of Examples 15 to 24. FIG. 12A is a diagram showing the specifications of the bone conduction toothbrushes D15 and D16 of Examples 15 and 16. FIG. 12B is a diagram showing the specifications of the bone conduction toothbrushes D17 and D18 of Examples 17 and 18. FIG. 12C is a diagram showing the specifications of the bone conduction toothbrush D19 of Example 19. FIG. 12D is a diagram showing the specifications of the bone conduction toothbrush D20 of Example 20. FIG. 12E is a diagram showing the specifications of the bone conduction toothbrush D21 of Example 21. FIG. 12F is a diagram showing the specifications of the bone conduction toothbrush D22 of Example 22. FIG. 12G is a diagram showing the specifications of the bone conduction toothbrush D23 of Example 23. FIG. 12H is a diagram showing the specifications of the bone conduction toothbrush D24 of Example 24.

(Manufacturing of bone conduction toothbrushes D15 to D24 of Examples 15 to 24)

Regarding the specifications of the ten bone conduction toothbrushes D15~D24, the "arrangement of the implant pores 16" is different, and the other specifications are set to be the same.

The "arrangement of the implanted pores 16" of each of the bone conduction toothbrushes D15 to D24 is shown in Figures 12A to 12H, and there are three to five rows arranged in the width direction of the brush head 12 (Figure 11). In Table 5, the multiple implanted pore rows N(1) located on one side of the width direction of the brush head 12 are set as the first row, and the implanted pore rows N(2) to N(5) are set as the second to fifth rows in sequence toward the other side of the width direction.

(Common part of the specification)

Area of the lower surface 18b of the piezoelectric element 18 (piezoelectric element region R1): 1.51 cm ²

Thickness of piezoelectric element 18: 0.9mm

Distance from the lower surface 18b of the piezoelectric element 18 to the bottom surface 16f of the implant hole 16 (H6): 1.6mm

Diameter of implant hole 16: 1.75mm

The depth of implant hole 16: 2.5mm

Bristle diameter: 5mil

Total number of bristles 17a per hole: 2122/ ^cm2

Bristle length 17a: 7mm

Length of flat line 19: 2.25mm

Position of piezoelectric element 18: refer to Figure 11

<Results>

As shown in Table 5, the evaluation of "sound hearing ease" of the bone conduction toothbrushes D15 to D24 of Examples 15 to 24, the bone conduction toothbrushes D18 and D19 of Examples 18 and 19 was used as an index, and the upper limit of the distance between adjacent horizontal lines in the length direction of the brush head (distance between horizontal lines M) was set to 1.5 mm.

Among the bone conduction toothbrushes D15 to D24 of Examples 15 to 24, the evaluation of "strength as a toothbrush" of the bone conduction toothbrushes D15 and D16 of Examples 15 and 16 was used as an indicator, and the lower limit value of the horizontal line distance M was set to 0.25 mm.

The upper limit of "(the sum of the lengths of the horizontal line 19)/(the length of the long axis direction of the implanted hair area)" is set to 94% from Example 23 and Example 24, taking the strength of the bone conduction toothbrush as an indicator.

Regarding the lower limit of "(sum of horizontal lengths)/(length of the long axis of the hair implantation area)", the ease of hearing of the sound is used as an indicator and is set to 53% from Example 20, Example 21, and Example 22.

In addition, in the case of the toothbrush D21 of Example 21 in which two rows of implanted pores N are arranged in the brush head, which meet the conditions of "the shortest distance between flat lines is 0.25 mm or more", and "(the sum of the lengths of flat lines)/(the length of the implanted pores area (the implanted surface 12a) in the longitudinal direction) is 53% or more", the sound judgment becomes "○". In addition, in the case of the toothbrush D22 of Example 22 in which three rows of implanted pores N are arranged, which meet the above conditions, the sound judgment becomes "◎".

Based on the above results, it can be seen that at least three rows of hair implantation holes N are required in the brush head to meet the requirements of "the shortest distance between flat lines is greater than 0.25 mm" and "(the sum of the lengths of flat lines)/(the length of the hair implantation area (hair implantation surface 12a) in the longitudinal direction) is greater than 53%".

The above describes the appropriate implementation of the present invention with reference to the accompanying drawings, but the present invention is certainly not limited to the examples described above. Anyone who is a practitioner in this field can obviously think of various changes or modifications within the scope of the technical ideas described in the scope of the patent application, and understand that these changes or modifications are of course also within the technical scope of the present invention.

10: Bone conduction toothbrush (toothbrush)

11: Brush structure

12: Brush head

12a: Hair-planted surface

13: Neck

14: Frame

15: Brush part

17: Hair bundle

17a: Bristles

22: Body

X, Y, Z: direction

Claims (9)

A toothbrush comprises: a brush structure having a piezoelectric element that oscillates by an arbitrary sound source data signal; and a body, on one end of which the brush structure is mounted and a current is supplied to the piezoelectric element. If a brush head having the piezoelectric element built therein or a brush head having a plurality of hair bundles including a plurality of hair implantation holes implanted in a hair implantation surface of the brush head contacts biological tissue in the oral cavity of a user, the piezoelectric element is oscillated by the piezoelectric element. The vibration of the piezoelectric element vibrated by the sound source data signal is transmitted to the bone through the biological tissue, so that the user recognizes the vibration as sound. The hair bundles bundled with multiple bristles are implanted in each implantation hole using a horizontal line. Among the arrangements of all the hair bundles implanted on the implantation surface, the arrangement of the hair bundles that meets the following two conditions 1 and 2 exists in at least three rows. The multiple implants arranged on the implantation surface At least a portion of the pores are arranged in a grid shape, and the ratio of the area of the area surrounded by a second imaginary line connecting the outer edges of the plurality of hair-implanting holes on the outermost side with the shortest distance among all the hair-implanting holes arranged in a grid shape to the area of the area surrounded by a first imaginary line connecting the outer edges of the plurality of hair-implanting holes on the outermost side with the shortest distance among all the hair-implanting holes arranged in the grid shape becomes more than 20%, <Condition 1> The distance between the horizontal lines punched into each of the multiple hair transplanting holes arranged in the length direction of the brush head is more than 0.25mm and less than 1.5mm <Condition 2> Relative to the length of the hair transplanting area in the length direction of each hair transplanting hole row, the ratio of the sum of the lengths of the multiple horizontal lines adjacent to each other in the length direction in the hair transplanting hole row is more than 53% and less than 94%. The toothbrush as claimed in claim 1, wherein when a sound source of 1000 Hz or more and 7000 Hz or less flows into the piezoelectric element, the vibration level of the brush portion becomes 45 dB SPL or more and 75 dB SPL or less. A toothbrush as claimed in claim 1, wherein the piezoelectric element is arranged in contact with the back side of a hair-implanting plate whose surface is set as the hair-implanting surface, and the ratio of the total area of the plurality of hair-implanting holes in the area overlapped with the piezoelectric element in the hair-implanting plate when viewed from above becomes 30% or more relative to the total area of all the hair-implanting holes set on the hair-implanting surface. A toothbrush as claimed in claim 1, wherein the ratio of the total area of the plurality of hair implantation holes existing in the hair implantation surface to the area overlapping with the piezoelectric element when viewed from above is 23% or more and 60% or less. A toothbrush as described in claim 1, wherein the distance from the lower surface of the piezoelectric element to the bottom surface of the hair implantation hole becomes greater than 0.4 mm and less than 1.6 mm. A toothbrush as described in claim 1, wherein the total number of all bristles implanted on the bristle implanting surface becomes greater than 600/cm2 and less than 2800/ ^cm2 relative to the area of the total bristle implanting region surrounded by a first imaginary line connecting the outer edges of a plurality of the bristle implanting holes located on the outermost side with the shortest distance among all the bristle implanting holes provided on the ^bristle implanting surface. A toothbrush as described in claim 6, wherein a part or all of the bristles include forked hairs, and relative to the area of the total hair-implanting area, the total number of the forked hairs of all the bristles implanted in the area becomes greater than ⁶⁰⁰ /cm2 and less than 11200/ ^cm2 . A toothbrush as claimed in claim 1, wherein the thickness obtained by adding the maximum thickness dimension of the piezoelectric element and the maximum thickness dimension of the hair-planting plate of the hair-planting surface becomes greater than 3.4 mm and less than 7.0 mm. A toothbrush as claimed in claim 1, wherein the ratio of the minimum hair length of the hair bundle becomes greater than 40% and less than 74% relative to the sum of the maximum thickness dimension of the piezoelectric element, the maximum thickness dimension of the hair-planting plate of the hair-planting surface, and the minimum hair length of the hair bundle.

Images