WO2021131696A1

WO2021131696A1 - Toothbrush

Info

Publication number: WO2021131696A1
Application number: PCT/JP2020/045809
Authority: WO
Inventors: 茉以佐竹
Original assignee: ライオン株式会社
Priority date: 2019-12-24
Filing date: 2020-12-09
Publication date: 2021-07-01
Also published as: JP2021101761A; TW202131877A

Abstract

The objective of the present invention is to provide a toothbrush capable of achieving satisfactory usability when fitted to an attachment. This toothbrush includes, in a long axis direction, a grip portion (16), a neck portion (15) positioned at the distal end of the grip portion, and a head portion (14) positioned at the distal end of the neck portion, wherein the toothbrush is fitted to an attachment which has an insertion hole in the long axis direction, in which the grip portion is inserted into the insertion hole from a tail portion (16a) side, and in which a bottom portion of the insertion hole is closed. In a side surface view seen in the width direction of the head portion, the thickness of the grip portion in a direction orthogonal to the long axis direction and the width direction increases continuously from the rear end of the tail portion in the long axis direction toward the distal end side, until a maximum position F, and the position in the long axis direction at which the thickness is greatest is a position at least 20 mm and at most 30 mm from the rear end.

Description

toothbrush

The present invention relates to a toothbrush.
The present application claims priority based on Japanese Patent Application No. 2019-233344 filed in Japan on December 24, 2019, the contents of which are incorporated herein by reference.

Appropriate brushing is necessary to prevent caries and periodontal disease, but children do not know how to brush properly, and adults also have brushing habits, so the level is high for the user alone. It was difficult to master tooth brushing skills.

In recent years, with the rise of Iot technology, the movement when brushing the part displayed on the screen of a mobile information terminal such as a smartphone is acquired by a sensor, and the obtained data is transferred to the mobile information terminal to determine the brushing position and brushing stroke. A so-called smart toothbrush that can evaluate toothbrushing skills by calculating is being developed and introduced.

For example, Patent Document 1 describes a sensor unit that detects a physical quantity related to a toothbrush, a wireless transmission unit that transmits a wireless signal indicating the detected physical quantity, and a holding unit that holds the rear end side of the grip portion of the inserted toothbrush. Toothbrush attachments are disclosed.

The toothbrush attachment described in Patent Document 1 is attached to the rear end side of the grip portion of the toothbrush in the holding portion and brushed with the toothbrush to obtain a wireless signal indicating a physical quantity detected by the sensor portion, for example, Bluetooth. (Registered trademark) It can be transmitted to the outside of a mobile information terminal (smartphone, etc.) that has activated the application by communication. Therefore, when the attachment described in Patent Document 1 is used, it is possible to receive a wireless signal at a position away from the hand even while brushing teeth and to know information on the user's tooth brushing behavior based on the wireless signal. Become.

Japanese Patent No. 6465122

It is important that the toothbrush does not easily come off the attachment during use. The toothbrush described in Patent Document 1 has a flat shape in which the grip portion has a small change in thickness. Therefore, regarding the ease of pulling out, the gripping portion is difficult to pull out because it is always in contact with the wall surface of the insertion hole until the gripping portion is completely pulled out. On the other hand, regarding ease of insertion, when the grip portion is inserted into the insertion hole of the attachment, the grip portion is always in contact with the wall surface of the insertion hole until the grip portion reaches the bottom of the insertion hole. .. In this case, there is a problem that it is difficult for the user to insert it.

The present invention has been made in consideration of the above points, and is good at mounting on an attachment by achieving both ease of inserting the grip portion into the insertion hole of the attachment and difficulty in pulling out during use. It is an object of the present invention to provide a toothbrush that can realize various usability.

According to the first aspect of the present invention, the toothbrush has a grip portion along the long axis direction, a neck portion located at the tip of the grip portion, and a head portion located at the tip of the neck portion. A toothbrush having an insertion hole along the long axis direction, the grip portion being inserted into the insertion hole from the tail side, and the head being attached to an attachment in which the bottom of the insertion hole is closed. In the side view seen along the width direction of the portion, the thickness of the grip portion in the major axis direction and in the direction orthogonal to the width direction is toward the tip end side from the rear end of the tail portion in the major axis direction. Provided is a toothbrush characterized in that the position in the major axis direction in which the thickness continues to increase to the maximum and the thickness is maximum is a position of 20 mm or more and 30 mm or less from the rear end.

Further, in the toothbrush according to one aspect of the present invention, in the side view, the curvature of the contour line on one side in the thickness direction from the rear end to the position where the maximum thickness is obtained in the grip portion is the other in the thickness direction. It is characterized in that it is smaller than the curvature of the contour line on the side.

Further, in the toothbrush according to one aspect of the present invention, in the side view, a circle having a radius of 5 mm, a radius of 15 mm, and a radius of 25 mm centered on the rear end of the tail portion is a contour on one side in the thickness direction of the grip portion. The points that intersect the lines are p1, p2, and p3, respectively, and the points that intersect the contour line on the other side in the thickness direction of the grip portion are p4, p5, and p6, respectively, and the radii of the circle passing through the points p1, p2, and p3 are defined. Is R1, and the radius of the circle passing through the points p4, p5, and p6 is R2, and the relationship that R2> R1 and the value represented by R2 / R1 is 1.1 or more and 2.4 or less is satisfied. It is characterized by.

Further, in the toothbrush according to one aspect of the present invention, in the side view, the thickness of the grip portion at a position L [mm] from the rear end of the tail portion in the long axis direction is x (L) [mm]. When represented by, it is characterized in that the relationship of x (25) -x (15) <1 and x (15) -x (5)> x (25) -x (15) is satisfied.

Further, in the toothbrush according to one aspect of the present invention, in the side view, a circle having a radius of 5 mm, a radius of 10 mm, and a radius of 15 mm centered on the rear end of the tail portion is a contour on one side in the thickness direction of the grip portion. The points that intersect the line are p11, p12, and p13, respectively, and the points that intersect the contour line on the other side in the thickness direction of the grip portion are p14, p15, and p16, respectively, and the radius of the circle passing through the points p11, p12, and p13. Is R3, the radius of the circle passing through the points p14, p15, and p16 is R4, and in the side view, the circle having a radius of 15 mm, a radius of 20 mm, and a radius of 25 mm centered on the rear end of the tail is the thickness of the grip portion. The points that intersect the contour line on one side in the radial direction are p21, p22, and p23, respectively, and the points that intersect the contour line on the other side in the thickness direction of the grip portion are p24, p25, and p26, respectively. Assuming that the radius of the circle passing through p23 is R5 and the radius of the circle passing through points p24, p25 and p26 is R6, the values represented by R4> R3, R6> R5 and R4 / R3 are 2.5 or more, 12. It is characterized in that it satisfies the relationship of 0 or less and the value represented by R6 / R5 is 1.1 or more and 2.5 or less.

In the present invention, good usability can be realized when the grip portion is attached to the attachment by achieving both the ease of inserting the grip portion into the insertion hole of the attachment and the difficulty of pulling out during use.

It is a figure which shows the embodiment of this invention, and is the external perspective view which shows the toothbrush 10 and the attachment 1 attached to the toothbrush 10. It is a front view of the toothbrush 10. It is a side view of the toothbrush 10. It is a partial side view which shows the tip side of the toothbrush 10. It is a side view which partially enlarged the tail part 16a of the grip part 16. It is a side view which partially enlarged the tail part 16a of the grip part 16. It is a side view which partially enlarged the tail part 16a of the grip part 16. It is an exploded perspective view of the attachment 1. It is sectional drawing of the attachment 1 in the plane parallel to the YZ plane. It is sectional drawing of the attachment 1 in the plane parallel to the XZ plane. FIG. 5 is a plan view of the housing 45 as viewed from the + Z side. It is an external perspective view of the 1st structure 40. It is a side view of the substrate 42. It is a flowchart which shows the operation when the switch part 51 is pressed from the state where the attachment 1 is stopped. It is a flowchart which shows the operation when the 1st operation mode is selected. It is a flowchart which shows the operation when the 2nd operation mode is selected. It is a flowchart which shows the operation when the switch part 51 is pressed in the 1st operation mode or the 2nd operation mode. It is a partial side view which shows the tip side of the toothbrush 10 of a modification.

Hereinafter, embodiments of the present invention for toothbrushes will be described with reference to FIGS. 1 to 18. The toothbrush in the present embodiment will be described by exemplifying a configuration in which the toothbrush is detachably attached to the toothbrush attachment.

Note that the following embodiments show one aspect of the present invention, do not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Further, in the following drawings, in order to make each configuration easy to understand, the scale and number of each structure are different from the actual structure.

FIG. 1 is an external perspective view showing a toothbrush 10 and an attachment 1 attached to the toothbrush 10. FIG. 2 is a front view of the toothbrush 10. FIG. 3 is a side view of the toothbrush 10. FIG. 4 is a partial side view showing the tip end side of the toothbrush 10.

[Toothbrush 10]
First, the toothbrush 10 will be described. The toothbrush 10 is not particularly limited in the material of the toothbrush 10 as long as the attachment 1 can be attached. The toothbrush 10 of the present embodiment is for infants as an example.

As shown in FIGS. 1 to 4, the toothbrush 10 has a handle body 11 and a brush portion 12. The handle body 11 has a head portion 14, a neck portion 15, and a grip portion 16.

In the following description, the direction is orthogonal to the mounting surface 73a of the attachment 1 described later, the substantially major axis direction of the handle body 11 in the toothbrush 10 is the Z direction, and the brush portion 12 extends with respect to the flocked surface 21a. The direction is the X direction, and the Z direction and the direction orthogonal to the X direction are appropriately used as the Y direction. Further, in the X direction, the + X side facing the flocked surface 21a is the front side, and the −X side opposite to the flocked surface 21a is the back side. In the Z direction, the side where the head portion 14 is located is the front end side, and the side where the grip portion 16 is located is the rear end side. Further, the X direction will be described as the thickness direction as appropriate, and the Y direction will be described as the width direction as appropriate.

A brush portion 12 is planted on the flocked surface 21a of the head portion 14. In addition, except for FIG. 4, the brush portion 12 is shown in a simplified manner.
The neck portion 15 is a portion that connects the head portion 14 and the grip portion 16. The width of the neck portion 15 is configured to be narrower than the minimum width of the head portion 14 and the grip portion 16. The thickness of the neck portion 15 can be, for example, the same as the thickness of the head portion 14. The grip portion 16 is a portion that the user of the toothbrush 10 grips by hand. The region including the rear end of the grip portion 16, that is, the rear end of the handle body 11, is referred to as a tail portion 16a.

In the present embodiment, the width is narrowed from the tip of the head portion 14 toward the grip portion 16, the amount of change in the width is large, and the position where the amount of change in the width is almost eliminated is the rear end and the neck of the head portion 14. The position of the boundary with the tip of the portion 15 is set. Further, the position where the width increases from the tip of the neck portion 15 toward the grip portion 16 and the amount of change in the width increases is defined as the position of the boundary between the rear end of the neck portion 15 and the tip of the grip portion 16.

As shown in FIG. 2, in the front view, the outer contour line on the most tip side of the outer contour line (contour line) on the + Y side of the grip portion 16 has a concave shape with the center of curvature located on the + Y side of the outer contour line. It is an arcuate curve. Each outer contour line on the tail side of the curve is an arc-shaped curve whose center of curvature is located on the −Y side and has a convex shape. In front view, the outer contour line on the + Y side and the outer contour line on the −Y side of the grip portion 16 are line-symmetric with respect to the center line extending in the Z direction. The width of the grip portion 16 in the front view gradually increases from the tip toward the tail side and then gradually decreases.

As shown in FIG. 3, in the side view, the outer contour line on the front side of the grip portion 16 has curves C1, C2, C3, C4, and C5. In the side view, the outer contour line on the back side of the grip portion 16 has curves C11, C12, C13, C14, C15, and C5. The curved surface C5 forms an outer contour line on the front side and the back side of the grip portion 16.

The curve C1 has a concave arc shape having a center of curvature on the front side, and the tip side is in contact with the front side of the neck portion 15. The curves C2 to C4 have a convex arc shape having a center of curvature on the back surface side. The curve C11 has a concave arc shape having a center of curvature on the back surface side, and the tip end side is in contact with the back surface side of the neck portion 15. The curves C12 to C13 have a concave arc shape having a center of curvature on the back surface side. The curves C14 to C15 have a convex arc shape having a center of curvature on the front side. The curve C5 has an arc shape having a center of curvature on the front end side and a convex shape on the rear end side, and is in contact with the curves C4 and C15.

In the side view, the thickness of the grip portion 16 continues to increase from the rear end of the tail portion 16a of the grip portion 16 to the maximum position F toward the tip side. As the position F, it is preferable that the distance LF from the rear end of the tail portion 16a is 20 mm or more and 30 mm or less. If the distance LF from the rear end of the tail portion 16a to the position F is less than 20 mm, the unevenness of the grip portion 16 fits into the attachment 1 in a state where the depth at the time of insertion cannot be sufficiently secured. 72 (see FIG. 8; details will be described later) cannot secure a sufficient contact distance with the wall surface, and the toothbrush 10 can be easily pulled out.

When the distance LF from the rear end of the tail portion 16a to the position F exceeds 30 mm, if the attachment 1 that can be inserted to the position F is used, the contact area between the wall surface of the insertion hole 72 and the grip portion 16 becomes long and during use. It becomes difficult to pull out, but the insertability is poor, and it becomes difficult for the user to pull out. On the other hand, when the distance LF from the rear end of the tail portion 16a to the position F exceeds 30 mm, if the attachment 1 that is not inserted to the position F is used, the attachment 1 to the grip portion 16 having a thickness (diameter) larger than that of the grip portion 16 The convex shape including the maximum thickness in the above is exposed, and the usability deteriorates.
By setting the distance LF from the rear end of the tail portion 16a to the position F to 20 mm or more and 30 mm or less, the toothbrush 10 inserted into the insertion hole 72 does not easily come off during use, and the insertability, usability, and the ease of use of the toothbrush 10 Ease of pulling out can be ensured.

In the side view, the curvature of the outer contour line on the front side from the rear end of the tail portion 16a to the position F in the grip portion 16 is smaller than the curvature of the outer contour line on the back side. That is, the outer contour line on the front side and the outer contour line on the back side in the thickness direction are formed asymmetrically.

When the outer contour line on the front side and the outer contour line on the back side are formed symmetrically, fitting with the attachment 1 occurs simultaneously on both sides in the thickness direction in the process of inserting the grip portion 16 into the insertion hole 72. Therefore, there is no space between the wall surface of the insertion hole 72 and the grip portion 16, and it is difficult to insert. Further, when the user inserts the grip portion 16 into the insertion hole 72, there is a problem that the orientation of the grip portion 16 is difficult to recognize. Further, in the insertion process, both the front side and the back side surfaces of the grip portion 16 serve as guides in contact with the wall surface of the insertion hole 72, but both sides of the grip portion 16 are always in contact with the wall surface of the insertion hole 72. Since it is in the state of being inserted, the insertability is lowered. Further, even when the grip portion 16 is pulled out from the insertion hole 72, the contacts on both sides are separated at the same time, resulting in instability.

On the other hand, in the present embodiment, since the outer contour line on the front side and the outer contour line on the back side are asymmetrically formed, the wall surfaces of the grip portion 16 and the insertion hole 72 are formed in the process of inserting the grip portion 16. By creating an appropriate space between and, the ease of insertion is improved. Further, since the surfaces on both sides have an asymmetrical shape with each other, the orientation of the grip portion 16 can be easily recognized when the user inserts the grip portion 16 into the insertion hole 72. In addition, the front surface having a large curvature serves as a guide that keeps contacting the insertion hole 72 during the insertion process, enabling stable insertion, and also on the back surface having a small curvature at this time. , A moderate space is created. Further, even when the user pulls out, the guide keeps contact with either the front side or the back side, so that the pulling is stable and easy.

FIG. 5 is a partially enlarged side view of the tail portion 16a of the grip portion 16.
As shown in FIG. 5, in the side view, the points where the circles having a radius of 5 mm, a radius of 15 mm, and a radius of 25 mm centered on the rear end of the 16a tail intersect with the outer contour line on the front side of the grip portion 16 are p1 and respectively. Let p2 and p3 be used, and the points intersecting the outer contour line on the back surface side of the grip portion 16 are p4, p5, and p6, respectively. Assuming that the radius of the circle E1 passing through the points p1, p2, and p3 is R1 and the radius of the circle E2 passing through the points p4, p5, and p6 is R2, the values represented by R2> R1 and R2 / R1 are 1. The relationship of 1 or more and 2.4 or less, preferably 1.3 or more and 2.0 or less is satisfied.

When the value represented by R2 / R1 is less than 1.1 (when the radii on the front side and the back side are almost the same), the side view of the grip portion 16 has a shape close to symmetry. In this case, as described above, in the process of inserting the grip portion 16, it is difficult to insert the grip portion 16 because there is no space between the wall surface of the insertion hole 72 and the grip portion 16. Further, when the value represented by R2 / R1 is less than 1.1, there is a problem that it is difficult for the user to recognize the orientation of the grip portion 16 when inserting the grip portion 16 into the insertion hole 72. Further, in the insertion process, both the front and rear surfaces of the grip portion serve as guides in contact with the insertion hole, but since both sides of the grip portion are always in contact with the insertion hole, the insertability is reduced (pulling out). The same is true for difficulty).

On the other hand, when the value represented by R2 / R1 exceeds 2.4, the difference between the radius R1 of the circle E1 on the front side and the radius R2 of the circle E2 on the back side becomes large. In this case, since the difference in shape between the front side and the back side becomes large, a large space is formed between the toothbrush 10 (grip portion 16) and the attachment 1 on the rounded side having a small radius. Therefore, although it is easy to insert the grip portion 16, there arises a problem that it is easy to come off during use.

On the other hand, in the present embodiment, by setting R2> R1 and the value represented by R2 / R1 to 1.1 or more and 2.4 or less, it is easy to insert the grip portion 16 into the insertion hole 72. When the user inserts the grip portion 16 into the insertion hole 72, the ease of recognizing the orientation of the grip portion 16 is improved, and the user can ensure stable pulling out of the grip portion 16 and the insertion hole. The space between the wall surface of the 72 and the grip portion 16 does not become too large, and the ease of pulling out during use can be suppressed.

FIG. 6 is a partially enlarged side view of the tail portion 16a of the grip portion 16.
As shown in FIG. 6, in the side view, the points where the circles (not shown) having a radius of 5 mm, a radius of 10 mm, and a radius of 15 mm centered on the rear end of the 16a tail intersect with the outer contour line of the grip portion 16, respectively. Let p11, p12, and p13, and p14, p15, and p16, respectively, at points that intersect the outer contour line on the back surface side of the grip portion 16. Let R3 be the radius of the circle E3 passing through the points p11, p12, and p13, and let R4 be the radius of the circle E4 passing through the points p14, p15, and p16.

Similarly, in the side view, the points where the circles (not shown) having a radius of 15 mm, a radius of 20 mm, and a radius of 25 mm centered on the rear end of the 16a tail intersect with the outer contour line of the grip portion 16 are p21, p22, respectively. Let p23 be, and p24, p25, and p26, respectively, at points that intersect the outer contour line on the back side of the grip portion 16. Let R5 be the radius of the circle E5 passing through the points p21, p22 and p23, and let R6 be the radius of the circle E6 passing through the points p24, p25 and p26.

At this time, in the tail portion 16a of the grip portion 16, the value represented by R4> R3, R6> R5, and R4 / R3 is 2.5 or more and 12.0 or less, and the value represented by R6 / R5 is 1. Both relationships of 1 or more and 2.5 or less are satisfied.

Insert when the value represented by R4 / R3 is less than 2.5 or the value represented by R6 / R5 is less than 1.1, that is, when the shape of the grip portion 16 on the tail 16a side is close to symmetry. In the process, the space between the wall surface of the insertion hole 72 and the grip portion 16 is small and it is difficult to insert. When the value represented by R4 / R3 exceeds 12.0 or when the value represented by R6 / R5 exceeds 2.5, that is, the difference between the radius R5 of the circle E5 and the radius R6 of the circle E6 When it is large, one of the ends of the grip 16 on the tail 16a side has a more rounded shape as compared with the other.

In this case, in the attachment 1, since the inclination of the wall surface on the opening side of the insertion hole 72 becomes large with respect to the insertion direction, a small appropriate space is inserted between the wall surface of the insertion hole 72 and the grip portion 16 in the insertion process. Hateful.

On the other hand, in the present embodiment, the value represented by R4 / R3 is 2.5 or more and 12.0 or less, and the value represented by R6 / R5 is 1.1 or more and 2.5 or less. By doing so, an appropriate space is formed between the wall surface of the insertion hole 72 and the grip portion 16 in the insertion process, which facilitates insertion.

FIG. 7 is a partially enlarged side view of the tail portion 16a of the grip portion 16.
As shown in FIG. 7, the grip portion 16 has a thickness of the grip portion 16 at a position of L [mm] from the rear end of the tail portion 16a to the tip side in the long axis direction in a side view x (L) [mm]. When represented by, the relationship of x (25) -x (15) <1 and x (15) -x (5)> x (25) -x (15) is satisfied. Further, the grip portion 16 satisfies the relationship of x (15) / x (5)> x (25) / x (15).

By satisfying the above relationship, a change in thickness can be obtained between the position of 15 mm on the tip side in the longitudinal direction from the rear end of the tail portion 16a near the maximum thickness position F of the grip portion 16 and the position of 25 mm. It is smaller than the change in thickness between the 5 mm position on the tip side and the 15 mm position. That is, the thickness change on the rear end side of the tail portion 16a is large, and the rear end side has a sharp shape. Since the rear end side of the tail portion 16a has a sharp shape, a space is created between the wall surface of the insertion hole 72 and the grip portion 16 in the insertion process, which facilitates insertion. Further, since the shape has a small change in thickness in the vicinity of the maximum thickness position F, the distance until a space is formed between the wall surface of the insertion hole 72 and the grip portion 16 becomes long in the extraction process, and the insertion hole 72 comes off during use. It becomes difficult.

Specific examples of the hard resin constituting the handle body 11 include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene methylene terephthalate (PCT), polyacetal (POM), and the like. Examples thereof include polystyrene (PS), acrylonitrile-butadiene-styrene resin (ABS), cellulose propionate (CP), polyarylate, polycarbonate, acrylonitrile-styrene copolymer resin (AS), and the like. The hard resin may be used alone or in combination of two or more.

Specific examples of the hard resin include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexylene methylene terephthalate (PCT), polyacetal (POM), polystyrene (PS), and acrylonitrile. -Examples include butadiene-styrene resin (ABS), cellulose propionate (CP), polyarylate, polycarbonate, acrylonitrile-styrene copolymer resin (AS), and the like. The hard resin may be used alone or in combination of two or more.

[Attachment 1]
Next, the attachment 1 will be described.
FIG. 8 is an exploded perspective view of the attachment 1.
The attachment 1 has a first structure 40 and a second structure 70.
The first structure 40 has a battery 41, a substrate 42, a speaker 43, a speaker film 44, a housing 45, a cap 46, and a connector cap 47.

FIG. 9 is a cross-sectional view of the attachment 1 on a plane parallel to the YZ plane. FIG. 10 is a cross-sectional view of the attachment 1 on a plane parallel to the XZ plane.
As shown in FIGS. 9 and 10, the housing 45 is formed of a hard resin and has a storage space 50 surrounded by a substantially circular bottom portion 48 and a substantially cylindrical side wall portion 49 when viewed in the Z direction. Have. The accommodation space 50 is open to the −Z side. In the accommodation space 50, the speaker film 44, the speaker 43, the substrate 42, and the battery 41 are sequentially accommodated from the bottom 48 side (−Z side).

FIG. 11 is a plan view of the housing 45 as viewed from the + Z side. FIG. 12 is an external perspective view of the first structure 40.
As shown in FIGS. 9 and 11, the side wall portion 49 has an outer peripheral surface that curves outward in a convex shape with respect to the center. Further, as shown in FIG. 10, a recess 58 recessed inward is provided on the + X side of the side wall portion 49. The recess 58 is formed in a groove shape extending in the Y direction. As shown in FIG. 12, the recess 58 is formed with a hole 59 that penetrates the side wall 49 in the X direction.

The cap 46 is made of hard resin and closes the accommodation space 50 when it is attached to the housing 45 from the + Z side. The cap 46 is fixed to the housing 45 with, for example, an adhesive.

FIG. 13 is a side view of the substrate 42.
The substrate 42 includes a switch unit 51, a detection unit 52, a communication unit 53, a connect unit 54, a control unit 55, and a light emitting element 56.

The switch unit 51 operates the operating states of the detection unit 52 and the communication unit 53.
The operation mode of the switch unit 51 is selected according to the operating state when the switch is pressed and the length of the pressed time (details will be described later). The switch portion 51 is mounted on the + X side end portion of the substrate 42. As shown in FIG. 10, the switch portion 51 is provided so as to face the hole portion 59. The switch portion 51 is arranged coaxially with the hole portion 59. The switch portion 51 is arranged inside the housing 45 with the outer peripheral surface 60 located on the + X side of the side wall portion 49 curved outward in a convex shape as a virtual surface 60. As an example, the switch portion 51 is arranged inside the housing 45 at a distance of 2 to 3 mm from the virtual surface 60. The switch unit 51 outputs a pressing signal to the control unit 55 by being pressed from the + X side via the hole portion 59.

The detection unit 52 detects a predetermined physical quantity of the toothbrush 10 to which the attachment 1 is attached. Examples of the predetermined physical quantity related to the toothbrush 10 include the direction of the brush portion 12, the moving direction, the moving speed, and the like. The detection unit 52 includes, for example, an acceleration sensor. As the acceleration sensor, for example, a three-axis acceleration sensor that detects acceleration in three directions can be used. A predetermined physical quantity related to the toothbrush 10 detected by the detection unit 52 is output to the control unit 55. As the acceleration sensor, a 6-axis acceleration sensor that detects acceleration in three directions and rotation in three directions may be used.

The communication unit 53 communicates (communicate processing) with an external device under the control of the control unit 55. The external device with which the communication unit 53 communicates is, for example, a mobile information terminal such as a smartphone, a tablet, or a laptop computer on which a predetermined application is installed. The mobile information terminal in this case also includes a desktop personal computer on which the above application is installed and capable of communicating with the communication unit 53. Examples of the communication method with the mobile information terminal by the communication unit 53 include Bluetooth (registered trademark) communication and Wifi communication, but a configuration in which communication is performed by another communication standard may be used.

The connect portion 54 is a connector to which the power supply cable 57 shown in FIG. 1 is connected. The cable 57 includes, for example, a USB cable, but may be a cable of another connection standard. The electric power supplied through the cable 57 and the connect unit 54 is stored in a power storage unit (not shown).

The light emitting element 56 is mounted on the substrate 42 at the end on the + X side so as to face the hole 59. The light emitting element 56 emits light of a color set for each operation mode toward the + X side under the control of the control unit 55. The light emitting element 56 is, for example, an LED element. The light emitting element 56 may be, for example, a light emitting diode or the like.

The control unit 55 immediately after detecting a predetermined physical quantity regarding the toothbrush 10 detected by the detection unit 52 according to the operating state when the switch unit 51 is pressed and the length of time when the switch unit 51 is pressed ( The first operation mode in which the physical quantity is transmitted to the mobile information terminal via the communication unit 53 in real time) and navigation is performed via the mobile information terminal, and the physical quantity is temporarily processed independently in the attachment 1 and is simplified when brushing teeth. The set operation mode is selected from the second operation mode in which navigation is performed and the first operation mode in operation or the third operation mode in which the second operation mode is forcibly terminated. The simple navigation when brushing teeth is performed by generating voice (for example, music reminiscent of brushing teeth and instruction of brushing position) via the speaker unit 43 instead of navigation using the physical quantity. Toothpaste. The simple navigation when brushing teeth is held in advance by a holding portion 69 mounted on the substrate 42. The holding unit 69 is, for example, a memory (ROM). The control unit 55 reads the simple navigation information from the holding unit in the second operation mode and outputs it via the speaker unit 43 (details will be described later). The control unit 55 is, for example, a central processing unit (CPU) mounted on the board 42. The detection unit 52, the communication unit 53, and the control unit 55 operate with electric power supplied from the battery 41 or the power storage unit.

The connector cap 47 is detachably attached to the connect portion 54. When the connector cap 47 is attached to the connect portion 54, the connect portion 54 is watertightly sealed. The connector cap 47 is made of a soft resin described later.

As shown in FIGS. 9 and 10, the second structure 70 is provided on the −Z side (bottom side) and is a fitting recess that is watertightly fitted with the first structure 40 (housing 45 and cap 46). It has a 71, an insertion hole 72 provided on the + Z side of the fitting recess 71 and to which the toothbrush 10 can be detachably attached, and a switch area (sealing portion) 74 provided at a position facing the switch portion 51. doing.

The fitting recess 71 is formed in a size and shape that can be fitted to the outer size and shape of the first structure 40. The fitting recess 71 is open to the −Z side and the −X side. The second structure 70 is engaged and supported by engaging and supporting the bottom of the housing 45 extending from the lower end along the XY plane around the opening on the −Z side of the fitting recess 71 from the −Z side. It has a part 73. The engaging portion 73 watertightly seals the bottom portion of the housing 45.

The surface of the engaging portion 73 on the −Z side is a mounting surface 73a that comes into contact with the attachment 1 when it is mounted on an object. Surrounded by the engaging portion 73, the bottom portion of the housing 45 is exposed at a position on the + Z side of the engaging portion 73. A connector cap 47 is fitted in the opening on the −X side of the second structure 70.

The switch area 74 is an area of the second structure 70 that faces the recess 58 and the hole 59, including the switch portion 51. The second structure 70 is curved outward in a convex shape following the outer peripheral surface of the side wall portion 49 which is curved outward in a convex shape around the switch region 74, and is recessed inward because it is flush with the virtual surface 60. The switch region 74 facing the recess 58 covers the recess 58 through a gap, and the hole 59 is watertightly sealed.

Inside the switch area 74, a protrusion 75 protruding toward the switch portion 51 is provided. The thickness of the switch region 74 excluding the protrusion 75 is formed to be thinner than the thickness around the switch region 74.

The insertion hole 72 is formed of a cavity extending in the Z direction and opening on the + Z side. The cross-sectional contour shape of the insertion hole 72 is a shape that follows the cross-sectional contour shape of the grip portion 16 on the −Z side of the toothbrush 10. More specifically, as shown in FIG. 9, the cross-sectional contour shape of the insertion hole 72 orthogonal to the X-axis is the outer contour line on the + Y side and the −Y side of the grip portion 16 shown in FIG. 2 in the front view. Corresponding to the outer contour line, it is line symmetric with respect to the center line extending in the Z direction. Further, the width of the cross-sectional contour shape of the insertion hole 72 orthogonal to the X-axis gradually decreases from the opening side to the bottom side.

As shown in FIG. 10, the cross-sectional contour shape of the insertion hole 72 orthogonal to the Y-axis corresponds to the outer contour line on the front side and the outer contour line on the back side of the grip portion 16 shown in FIG. 3 in the front view. Therefore, it is asymmetric with respect to the center line extending in the Z direction. More specifically, the width of the cross-sectional contour shape of the insertion hole 72 orthogonal to the Y-axis continues to gradually decrease from the opening side to the bottom side. In the cross section orthogonal to the Y axis corresponding to the side view of the toothbrush 10, the curvature of the outer contour line on the + X side corresponding to the front side of the toothbrush 10 from the position where the insertion hole 72 has the maximum width to the bottom is the curvature of the toothbrush 10. It is smaller than the curvature of the outer contour line on the -X side corresponding to the back side of. That is, the insertion hole 72 is formed so that the outer contour line on the + X side and the outer contour line on the −X side are asymmetrical.

The distance in the Z direction between the opening side end of the external contour line on the + X side of the insertion hole 72 and the bottom of the insertion hole 72 (that is, the depth at which the front side of the grip portion 16 is inserted into the insertion hole) is, for example, It is 25 mm or more and 30 mm or less. The distance between the opening side end of the external contour line on the −X side of the insertion hole 72 and the bottom of the insertion hole 72 in the Z direction (that is, the depth at which the back side of the grip portion 16 is inserted into the insertion hole) is, for example, , 35 mm or more, 40 mm or less.

The size of the insertion hole 72 is set so that the grip portion 16 of the toothbrush 10 inserted into the cavity is held by soft press fitting. When the grip portion 16 is inserted into the insertion hole 72, the front side (the side where the brush portion 12 is provided) of the toothbrush 10 is the same as the side where the switch region 74 is arranged. That is, in the attachment 1, the switch portion 51 and the switch area 74 are arranged on the front side of the toothbrush 10.

As shown in FIG. 9, in the second structure 70, when viewed from the + X side, the outer contours on both sides in the Y direction are line-symmetric with respect to the axis extending in the Z direction. As shown in FIG. 10, in the second structure 70, when viewed from the + Y side, the outer contours on both sides in the Y direction are asymmetric with respect to the axis extending in the Z direction.

More specifically, the second structure 70 is provided with a first curved surface 81 that curves in a convex shape on the front side where the switch portion 51 is arranged when viewed from the + Y side. Further, the second structure 70 has a second curved surface 82 that is curved in a concave shape on the back surface side (−X side) opposite to the front surface side, and a protrusion 83 that protrudes to the back surface side. The second curved surface 82 is provided on the + Z side (upper side) of the protrusion 83. Further, from the protrusion 83 to the bottom of the second structure 70, a third curved surface 84 that curves in a convex shape is provided on the back surface side. The surface of the connector cap 47 is formed flush with the third curved surface 84.

The second structure 70 is made of a soft resin. As the soft resin forming the second structure 70 and the connector cap 47 described above, for example, the shore hardness A is preferably 20 or more and 90 or less, more preferably 30 or more and 70 or less, still more preferably 40 or more and 60. The following styrene-based elastomers. Examples of such a soft resin include elastomer resins such as polyolefin-based elastomers, styrene-based elastomers, and polyester-based elastomers. Among them, styrene-based elastomers are preferable from the viewpoint of weldability with polypropylene (PP). ..
The thickness of the second structure 70 at the portion covering the housing 45 is preferably 0.5 mm or more and 5.0 mm or less, more preferably 1.0 mm or more and 3.0 mm or less, and further preferably 1 It is .2 mm or more and 1.8 mm or less.

The attachment 1 having the above configuration is attached to the toothbrush 10 by inserting the grip portion 16 of the toothbrush 10 into the insertion hole 72. Since the grip portion 16 is softly press-fitted into the insertion hole 72, brushing can be smoothly performed without the toothbrush 10 being detached from the attachment 1 when the attachment 1 is gripped and the teeth are brushed.

Further, in the side view, the outer contour line on the front side and the outer contour line on the back side of the tail portion 16a in the grip portion 16 are asymmetrical and have the above-described configuration. Therefore, the toothbrush 10 inserted into the insertion hole 72. Is not easy to come off during use, and good insertability, usability and ease of pulling out of the toothbrush 10 can be ensured.

When gripping the attachment 1, for example, the thumb is placed on the first curved surface 81 (switch area 74) located on the front side where the brush portion 12 is provided, and the index finger is placed on the second curved surface 82 located on the back side. With the second structure 70 sandwiched between them, the attachment 1 is gripped with the bottom surface of the second structure 70 supported by the middle finger. By gripping at three places in this way, the attachment 1 can be held easily and stably.

When operating the attachment 1, the switch area 74 is pushed toward the back side with the thumb, and the switch part 51 is pushed through the protrusion 75. The second structure 70 on the front side covers the housing 45 made of hard resin around the switch region 74 and is not easily deformed, but the switch region 74 has a gap formed between it and the recess 58. Since it is easily deformed to the back side, the position of the switch portion 51 can be easily recognized.

Further, since the switch region 74 is formed thinner than the surroundings, it is easily deformed, and the switch portion 51 can be pushed in with a small resistance.

For example, when a child grips the attachment 1, the thumb is placed on the first curved surface 81 (switch area 74) located on the front side where the brush portion 12 is provided, and the index finger is placed on the second curved surface 82 located on the back side. It is preferable to support the bottom surface of the second structure 70 with the middle finger in a state where the second structure 70 is sandwiched between the two and the second structure 70 from the viewpoint of convenient and stable holding.

Subsequently, a procedure for brushing teeth using the attachment 1 to which the toothbrush 10 is attached will be described with reference to FIGS. 14 to 17.
FIG. 14 is a flowchart showing an operation when the switch unit 51 is pressed while the attachment 1 is stopped. FIG. 15 is a flowchart showing an operation when the first operation mode is selected. FIG. 16 is a flowchart showing an operation when the second operation mode is selected. FIG. 17 is a flowchart showing an operation when the switch unit 51 is pressed in the first operation mode or the second operation mode.

As shown in FIG. 14, when the switch unit 51 is pressed from the stopped operation state (step S1), the control unit 55 measures the time when the switch unit 51 is pressed (step S2). The control unit 55 determines whether or not the length of time that the switch unit 51 is pressed is within the first range (for example, 0.01 seconds or more and 0.5 seconds or less) (step S3). The control unit 55 operates the first operation mode if the pressing time length of the switch unit 51 is in the first range (step S4). On the other hand, in step S3, if the pressing time length of the switch unit 51 is outside the first range, the control unit 55 has the pressing time length of the switch unit 51 in the second range (for example, 2.0 seconds or more). It is determined whether or not it is 6.0 seconds or less (step S5). In step S5, if the pressing time length of the switch unit 51 is within the second range, the control unit 55 operates the second operation mode (step S6). The difference between the longest value of the first range and the shortest value of the second range is 2.0 seconds or more and 6.0 seconds or less so that the difference between the first range and the second range becomes clear. Is preferable, and it is more preferably 3.5 seconds or more and 4.5 seconds or less.

On the other hand, in step S5, when the pressing time length is out of the second range, the control unit 55 outputs an error because the operation mode corresponding to the pressing time length is not set (step S7). .. In step S5, when the pressing time length is out of the second range and an error is determined, the control unit 55 may not accept the pressing operation of the switch unit 51 and may not respond.

When operating the first operation mode in step S4, the control unit 55 causes the light emitting element 56 to emit blue light corresponding to the first operation mode as an example. Further, when the second operation mode is operated in the step S6, the control unit 55 causes the light emitting element 56 to emit white light corresponding to the second operation mode as an example. The blue light or white light emitted from the light emitting element 56 illuminates the switch region 74 from the inside through the hole 59. Since the thickness of the switch region 74 is formed to be thinner than the thickness of the surroundings, at least a part of the emitted blue light or white light passes through the switch region 74.

Therefore, by visually recognizing the color display of the illuminated switch area 74, the user can easily visually recognize the operation mode set according to the length of time that the switch unit 51 is pushed through the switch area 74. Will be possible. That is, the light emitting element 56 and the switch region 74 constitute a display unit that displays the display corresponding to the selected operation mode by color display.

[First operation mode]
As shown in FIG. 15, when the first operation mode is selected and operated in step S4, the control unit 55 communicates with the mobile information terminal via the communication unit 53 (step S8) and installs the mobile information terminal. It is determined whether or not it is possible to connect to the installed application (step S9). At this time, if the application cannot be connected to the mobile information terminal due to reasons such as the application not being started, the control unit 55 outputs an error (step S10). In step S9, if the application cannot be connected, the control unit 55 may not accept the selection of the first operation mode and may not respond.

On the other hand, if the application can be connected in step S9, the control unit 55 determines whether or not there is a physical quantity accumulated in the second operation mode at the time of the previous tooth brushing (step S11), but steps S11 and S12 will be described later.

After connecting to the control unit 55 (attachment 1), the application starts navigation related to tooth brushing (step S13). In the first operation mode, when the user brushes the teeth according to the navigation emitted from the mobile information terminal, the control unit 55 applies the physical quantity related to the toothbrush 10 detected by the detection unit 52 via the communication unit 53. (Step S14).

From the analysis result of the physical quantity of the toothbrush 10 transmitted from the attachment 1, for example, the posture of the toothbrush 10, the movement of the toothbrush 10 (movement distance, movement speed, movement path, etc. of the brush portion 12 of the toothbrush 10), brushing angle ( The angle of contact of the brush surface of the toothbrush 10 with respect to the teeth and gums), the number of brushings, the brushing position (the part of the tooth in contact with the toothbrush filament), and the brushing pressure (the stress value applied to the teeth from the brush surface of the toothbrush 10 and its change) ) And other parameters that represent the user's toothbrushing behavior are generated and evaluated.

After that, the app continues navigation while reflecting the evaluation result (step S15). After that, the tooth brushing is completed, the evaluation result is notified, and the first operation mode is completed (step S16).

[Second operation mode]
As shown in FIG. 16, when the second operation mode in which the attachment 1 independently navigates without communicating with the mobile information terminal is selected and operated in step S6, the control unit 55 uses music or the like. The simple navigation is started (step S17). The control unit 55 holds the simple navigation information (program) in the holding unit 69, and when the second operation mode is activated, the held program is activated to execute the simple navigation. This simple navigation is emitted from the speaker 43 under the control of the control unit 55.

In the second operation mode, when the user brushes the teeth according to the simple navigation, the control unit 55 (or a storage unit (not shown)) accumulates the physical quantity of the toothbrush 10 detected by the detection unit 52 (step S18). ). That is, in the two operation modes, the navigation is performed in a state where the detected physical quantity of the toothbrush 10 is not reflected. After that, the second operation mode ends by notifying that the tooth brushing has been completed (step S19).

In the second operation mode, the accumulated physical quantity related to the toothbrush 10 is transmitted to the application after the first operation mode is operated and the connection with the application is confirmed in step S9 shown in FIG. 15 (step S12). ).

[Third operation mode]
In the first operation mode and the second operation mode, the switch unit 51 is pressed and operated when the attachment 1 is in the operation stopped state, but the attachment 1 of the present embodiment has the first operation mode or the second operation mode. It has a third operation mode that operates when the switch unit 51 is pushed during operation.

As shown in FIG. 17, when the switch unit 51 is pressed while the first operation mode or the second operation mode is operating in step S20, the control unit 55 measures the pressing time of the switch unit 51 (step S21). ). The control unit 55 determines whether or not the length of time that the switch unit 51 is pressed is a predetermined time (for example, 1.0 second) or more (step S22), and unintentionally presses the switch unit 51 during brushing. If the pressing time is less than the predetermined time due to such reasons, the pressing information of the switch unit 51 is passed through to continue the first operation mode or the second operation mode.

On the other hand, when the pressing time of the switch unit 51 measured in step S22 is longer than a predetermined time, the third operation mode is operated and the operation in the first operation mode or the second operation mode is forcibly terminated (step S25). .. By operating the third operation mode in this way, even if an unexpected situation occurs, it becomes possible to deal with it.

Note that the control unit 55 stops the light emission by the light emitting element 56 when operating the third operation mode. As a result, the lighting to the switch area 74 is stopped and turned off, so that the user can easily visually recognize that the forced termination (the third operation mode is in operation).

As described above, in the toothbrush 10 of the present embodiment, even when the tail portion 16a is inserted into the insertion hole 72 of the attachment 1 and the toothbrush is brushed according to the navigation, the toothbrush 10 does not separate from the attachment 1 and is smooth. Can be brushed.

Further, in the present embodiment, since the outer contour lines of the front side and the back side of the toothbrush 10 are asymmetrical in the side view, the orientation of the grip portion 16 can be easily recognized. Further, in the second structure 70, in the side view, the front side on which the switch portion 51 is provided and the back side opposite to the front side are formed in an asymmetric outer contour, so that the second structure 70 has an asymmetric outer contour. When the 70 is gripped, the thumb naturally easily hits the front side, and the operation to the switch area 74 provided on the front side becomes easy.

[Modification example of toothbrush 10]
In the above embodiment, the structure in which the handle body 11 is formed of the hard resin is illustrated, but the structure may be made of the hard resin and the soft resin.
FIG. 18 is a partial side view showing the tip end side of the modified toothbrush 10.

The toothbrush 10 shown in FIG. 18 has a core member 17 made of a hard resin that constitutes a part of a head portion 14, a neck portion 15, and a grip portion 16.

The head portion 14 has a base member 21 that forms a part of the core member 17, and a soft portion 22 formed of a soft resin that covers the base member 21. A brush portion 12 is planted on the flocked surface 21a of the base member 21.

The neck portion 15 has a core portion 25 which is a component of the core member 17 and a soft portion 26. The core portion 25 extends in the Z direction (extending direction of the neck portion 15) and penetrates the neck portion 15, and extends in the Z direction, and one end thereof is the first portion 31. It has a second portion 32 that is integrated and arranged as part of the grip portion 16.

The first part 31 has the same thickness in the Z direction. The first portion 31 has a bending strength when an external force applied to the −X side is applied to the head portion 14, and a bending strength when an external force is applied to the head portion 14 in the Y direction (+ Y side or −Y side). Is set larger than. For example, the cross-sectional shape of the first portion 31 parallel to the XY plane is an elliptical shape with the X direction as the major axis (major axis) direction.

As a specific example of the hard resin, the hard resin described in the above embodiment can be used.
As the soft resin, for example, a soft resin having a hardness of JIS K 7215 Shore hardness A of preferably 20 or more and 90 or less, more preferably 30 or more and 70 or less, still more preferably 40 or more and 60 or less. Good to use.
As such a soft resin, the same soft resin as the soft resin constituting the second structure 70 described above can be used.

Since the bending strength of the first portion 31 in the X direction is larger than the bending strength in the Y direction, the neck portion 15 exerts a force when pressing the tip of the brush portion 12 against the teeth, interdental teeth, or the like when brushing the teeth. It is hard to be deformed in the direction in which the brush portion 12 is applied, and the tip of the brush portion 12 can be firmly pressed against the teeth or between the teeth. On the other hand, since the bending strength of the first portion 31 in the Y direction is smaller than the bending strength in the X direction, the neck portion 15 can be bent in the Y direction when an external force is applied. As a result, the force applied to the tip of the head portion 14 can be released, so that damage to the oral cavity of the user of the toothbrush 10 can be suppressed.

The grip portion 16 is a portion to be gripped by the user of the toothbrush 10 and is made of the soft resin 2. By forming the grip portion 16 with a soft resin, the grip portion 16 is deformed when a strong external force is applied from the rear end of the toothbrush 10 toward the tip of the head portion 14 while the toothbrush 10 is held in the mouth. It is possible to make (bend). As a result, not only the neck portion 15 but also the grip portion 16 is bent, so that the external force from the rear end of the toothbrush 10 toward the tip of the head portion 14 can be released in a direction different from this, so that the toothbrush 10 can be released. It is possible to prevent damage to the oral cavity of the user.

Although the preferred embodiments according to the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. The various shapes and combinations of the constituent members shown in the above-mentioned examples are examples, and can be variously changed based on design requirements and the like within a range that does not deviate from the gist of the present invention.

For example, the materials constituting the toothbrush 10, the first structure 40, and the second structure 70 illustrated in the above embodiment are examples, and other materials may be used.

The present invention can be applied to a toothbrush.

1 ... Attachment, 10 ... Toothbrush, 14 ... Head, 15 ... Neck, 16 ... Grip, 16a ... Tail, 72 ... Insertion hole

Claims

A toothbrush having a grip portion along a major axis direction, a neck portion located at the tip of the grip portion, and a head portion located at the tip of the neck portion.
A toothbrush that has an insertion hole along the long axis direction, the grip portion is inserted into the insertion hole from the tail side located on the rear end side, and the bottom of the insertion hole is closed. And
In the side view seen along the width direction of the head portion, the thickness of the grip portion in the major axis direction and the direction orthogonal to the width direction is from the rear end to the tip side of the tail portion in the major axis direction. Continues to increase to the maximum position toward
A toothbrush characterized in that the position in the long axis direction where the thickness is maximum is a position of 20 mm or more and 30 mm or less from the rear end.
In the side view, the curvature of the contour line on one side in the thickness direction from the rear end to the position where the maximum thickness is obtained in the grip portion is smaller than the curvature of the contour line on the other side in the thickness direction.
The toothbrush according to claim 1.
In the side view, the points where the circles having a radius of 5 mm, a radius of 15 mm, and a radius of 25 mm centered on the rear end of the tail intersect with the contour line on one side in the thickness direction of the grip portion are designated as p1, p2, and p3, respectively. , P4, p5, and p6 are the points that intersect the contour line on the other side of the grip portion in the thickness direction, respectively.
Let R1 be the radius of the circle passing through the points p1, p2, and p3, and R2 be the radius of the circle passing through the points p4, p5, and p6.
Satisfy the relationship where R2> R1 and the value represented by R2 / R1 is 1.1 or more and 2.4 or less.
The toothbrush according to claim 1 or 2.
In the side view, when the thickness of the grip portion at the position L [mm] from the rear end of the tail portion in the long axis direction is represented by x (L) [mm],
Satisfy the relationship of x (25) -x (15) <1 and x (15) -x (5)> x (25) -x (15).
The toothbrush according to any one of claims 1 to 3.
In the side view, the points where the circles having a radius of 5 mm, a radius of 10 mm, and a radius of 15 mm centered on the rear end of the tail intersect with the contour line on one side in the thickness direction of the grip portion are designated as p11, p12, and p13, respectively. , P14, p15, and p16, respectively, at points that intersect the contour line on the other side of the grip portion in the thickness direction.
The radius of the circle passing through the points p11, p12 and p13 is R3, and the radius of the circle passing through the points p14, p15 and p16 is R4.
In the side view, the points where the circles having a radius of 15 mm, a radius of 20 mm, and a radius of 25 mm centered on the rear end of the tail intersect with the contour line on one side in the thickness direction of the grip portion are designated as p21, p22, and p23, respectively. , P24, p25, and p26, respectively, at points that intersect the contour line on the other side of the grip portion in the thickness direction.
Let R5 be the radius of the circle passing through the points p21, p22 and p23, and R6 be the radius of the circle passing through the points p24, p25 and p26.
A relationship in which the values represented by R4> R3, R6> R5, and R4 / R3 are 2.5 or more and 12.0 or less, and the values represented by R6 / R5 are 1.1 or more and 2.5 or less. Satisfied,
The toothbrush according to any one of claims 1 to 4.