JP7724562B2 - toothbrush - Google Patents

Description

The present invention relates to toothbrushes, particularly those designed for proper cleaning.

Traditionally, toothbrushes have various configurations for preventing cavities and periodontal disease. For example, Patent Document 1 discloses a toothbrush that takes into consideration the shape of the head and the arrangement of bristle bundles, with the aim of enabling appropriate tooth brushing according to the shape of the teeth. The toothbrush has a configuration in which multiple bristle bundle groups, each consisting of multiple bristle bundles, are arranged with a gap between them that runs from one longitudinal edge of the head to the other, and the gap is wider than the spacing between the bristle bundles that make up the bristle group.

JP 2017-94183 A

As described above, even if a toothbrush is designed to prevent cavities and periodontal disease, brushing by the user can still have adverse effects on the teeth and gums, as described below.
In other words, the inventor has discovered that in recent years, with the rise in awareness of oral hygiene in society, toothbrush users are brushing their teeth excessively, which has resulted in gingival recession near the border between the teeth and gums, abrasion of the exposed tooth (cementum) by the toothbrush, and even chipping (substantial loss).

However, the conventional toothbrushes mentioned above did not take into consideration the adverse effects on teeth, dentition, and gums caused by improper brushing, such as wedge-shaped defects.

Therefore, in light of the current situation in which wear and wedge-shaped defects caused by excessive toothbrushing are common, the primary object of this invention is to provide a toothbrush that allows for proper brushing that reduces the risk of adverse effects on teeth, dentition, and gums caused by excessive toothbrushing.

The first invention of the present invention comprises a working unit that is made up of bristle bundles or groups of bristle bundles protruding from the surface of the head and that brushes the teeth in the dentition, and a stabilizing unit that is made up of bristle bundles or groups of bristle bundles or members other than bristle bundles or groups of bristle bundles and that guides the working unit to a target position in an appropriate posture relative to the front side of the teeth in response to a user's operation, making it easier to brush in a stable state, and at least one of the working unit and the stabilizing unit has a longitudinal direction that is aligned along the extension direction of the head, and a longitudinal direction that is aligned along a direction that intersects the extension direction of the head. The working part and the stabilizing part arranged along the extension direction of the head are spaced apart from each other, and the working part and the stabilizing part arranged along a direction intersecting the extension direction of the head are inclined relative to the other when viewed in the extension direction of the head, and the stabilizing part arranged along the direction intersecting the extension direction of the head is divided into two stabilizing parts, and the two stabilizing parts include one stabilizing part for maintaining a constant distance between the toothbrush and the tooth surface and the other stabilizing part for preventing rolling around the axis of the extension direction .
The present invention can be summarized as follows: By incorporating the concept of a working part and a stabilizing part into the toothbrush, it is possible to prevent the pressure of the toothbrush from concentrating on the protruding parts of the dentition, and when brushing highly uneven dentition surfaces, it is possible to prevent the toothbrush head from moving (pitching or rolling) and ensure that the brushing surface of the toothbrush always contacts perpendicularly with the tangents (contact surfaces) of all surfaces, including the raised surfaces, of the teeth.

The second invention is a toothbrush according to the first invention, in which the sets of working parts and stabilizing parts include both those arranged along the extension direction of the head and those arranged along a direction intersecting the extension direction of the head, and the brushing surface formed by the working parts arranged along the extension direction of the head and the brushing surface formed by the stabilizing parts arranged along the extension direction of the head are at the same height, and the brushing surface formed by the working parts arranged along the direction intersecting the extension direction of the head is located higher, when viewed in the extension direction of the head, than the brushing surface formed by the stabilizing parts arranged along the direction intersecting the extension direction of the head.

The third invention is the toothbrush of the second invention, wherein the working parts arranged in a direction intersecting the extension direction of the head are formed symmetrically, when viewed in the extension direction of the head, with respect to the stabilizing parts arranged in a direction intersecting the extension direction of the head.

The fourth invention is the toothbrush of the first invention, wherein the sets of working parts and stabilizing parts include only those arranged along the extension direction of the head, the brushing surface formed by the working parts arranged along the extension direction of the head and the brushing surface formed by the stabilizing parts arranged along the extension direction of the head are the same height, and the brushing surface formed by the working parts arranged along a direction intersecting the extension direction of the head has a larger dimension along the direction intersecting the extension direction of the head when viewed in a direction parallel to the surface of the head than the brushing surface formed by the stabilizing parts arranged along the direction intersecting the extension direction of the head.

The fifth aspect of the present invention is the toothbrush of the fourth aspect of the present invention, in which the brushing surfaces of the working part and the stabilizing part each have a dimension in a direction intersecting the extension direction of the head that increases from the tip to the rear end of the head when viewed in a plane parallel to the surface of the head.

A sixth aspect of the present invention is a toothbrush comprising a working part consisting of a tuft or group of tufts protruding from the surface of a head, and a stabilizing part consisting of a tuft or group of tufts or a member other than a tuft or group of tufts, wherein the working part and the stabilizing part are at least one of those whose longitudinal direction is an arrangement direction along the extension direction of the head, and those whose longitudinal direction is an arrangement direction intersecting the extension direction of the head, the working part and the stabilizing part being arranged along the extension direction of the head, are spaced apart from each other, and the toothbrush comprises a handle part for operating the head, and a neck part connecting the head and the handle part, the neck part connecting the head to the handle part at a position obtained by shifting the head in two directions perpendicular to the extension direction of the head when viewed in the extension direction of the head, and where the surface of the head is on the side facing the handle part.

The seventh invention of the present invention is the toothbrush of the sixth invention, wherein each of the brushing surfaces of the working part and the stabilizing part, when viewed in a plane parallel to the surface of the head, has a dimension along a direction intersecting the extension direction of the head that increases from the tip to the rear end of the head.

The present invention as described above has the effect of enabling proper brushing that reduces the risk of adverse effects on teeth, dentition, and gums.

The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the invention, which proceeds with reference to the drawings.

1 is a perspective view showing the configuration of a main part of a toothbrush according to a first embodiment of the present invention; 2A is a front view showing the configuration of the main part of the toothbrush according to the first embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. 1 is a plan view showing the configuration of a main part of a toothbrush according to a first embodiment of the present invention; 4A is a view of the toothbrush according to the first embodiment of the present invention placed against the buccal surface of the left lower jaw dentition, viewed from the occlusal surface, and FIG. 4B is a cross-sectional view taken along the line B-B in FIG. 4A. 1A is a front view showing the configuration of a toothbrush according to a first modification of the first embodiment of the present invention, and FIG. 1B is a plan view showing the configuration of a toothbrush according to the first modification of the first embodiment of the present invention. 1A is a front view showing the configuration of a toothbrush according to another modified example 1 of the first embodiment of the present invention, and FIG. 1B is a plan view showing the configuration of a toothbrush according to another modified example 1 of the first embodiment of the present invention. 1A is a front view showing the configuration of a toothbrush according to a second modification of the first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line CC of FIG. FIG. 10 is a plan view showing the configuration of a toothbrush according to a second modified example of the first embodiment of the present invention. 1A is a front view showing the configuration of a toothbrush according to a third variation of the first embodiment of the present invention, and FIG. 1B is a plan view showing the configuration of a toothbrush according to the third variation of the first embodiment of the present invention. (A) is a right side view showing the configuration of a toothbrush according to a second embodiment of the present invention, (B) is a front view showing the configuration of a toothbrush according to a second embodiment of the present invention, and (C) is a plan view showing the configuration of a toothbrush according to a second embodiment of the present invention. (A) is a front view showing the configuration of a toothbrush according to a first variant of the second embodiment of the present invention, and (B) is a plan view showing the configuration of a toothbrush according to the first variant of the second embodiment of the present invention. (A) is a right side view showing the configuration of a toothbrush according to a second variant of the second embodiment of the present invention, (B) is a front view showing the configuration of a toothbrush according to a second variant of the second embodiment of the present invention, and (C) is a plan view showing the configuration of a toothbrush according to a second variant of the second embodiment of the present invention. (A) is a right side view showing the configuration of a toothbrush according to a third variation of the second embodiment of the present invention; (B) is a plan view showing the configuration of a toothbrush according to the third variation of the second embodiment of the present invention; (C) is a right side view showing the configuration of a toothbrush according to another third variation of the second embodiment of the present invention; and (D) is a plan view showing the configuration of a toothbrush according to another third variation of the second embodiment of the present invention. (A) is a right side view showing the configuration of a toothbrush according to a third embodiment of the present invention, (B) is a bottom view showing the configuration of a toothbrush according to the third embodiment of the present invention, and (C) is a cross-sectional view taken along the line D-D of (B). 10A and 10B are diagrams illustrating a state in which a toothbrush according to a third embodiment of the present invention is used. FIG. 10 is a perspective view showing the configuration of a toothbrush according to a fourth embodiment of the present invention. FIG. 10 is a plan view showing the configuration of a toothbrush according to a fourth embodiment of the present invention. (A) is a right side view showing the configuration of a toothbrush according to another embodiment of the present invention, (B) is a bottom view showing the configuration of a toothbrush according to another embodiment of the present invention, and (C) is an E-E cross-sectional view of (B). 1A is a plan view showing the configuration of the main parts of a toothbrush according to a first embodiment of the present invention; FIG. 19B(B) is a diagram showing the toothbrush according to the first embodiment of the present invention applied to the upper and lower left jaw teeth in a closed-mouth position, with the toothbrush lightly contacting the upper and lower jaw teeth, covering the buccal surfaces of the upper and lower teeth simultaneously. 19C is a cross-sectional view taken along the line F-F of FIG. 19B(B). FIG. 10 is a perspective view showing the configuration of the main parts of a toothbrush according to a fifth embodiment of the present invention. 21A is a front view showing the configuration of the main part of a toothbrush according to a fifth embodiment of the present invention, and FIG. 21B is a cross-sectional view taken along line GG of FIG. 21A. 22(A) is a view from the occlusal surface of a toothbrush according to the fifth embodiment of the present invention placed against the lingual side of the left mandibular dentition, and FIG. 22(B) is a cross-sectional view taken along the line H-H in FIG. 22(A).

(First embodiment)
FIG. 1 is a perspective view showing the configuration of the main parts of a toothbrush according to a first embodiment of the present invention, FIG. 2(A) is a front view showing the configuration of the main parts of the toothbrush according to the first embodiment, FIG. 2(B) is a cross-sectional view taken along line A-A of FIG. 2(A), and FIG. 3 is a plan view showing the configuration of the main parts of a toothbrush according to the first embodiment.

As shown in the figures, toothbrush 100 according to the first embodiment of the present invention comprises head 110, brush section 120, which is embedded in the main surface of head 110 and contains bristle bundles that form the brush body for brushing teeth, and neck section 130, which connects head 110 to a handle section (not shown) that allows the user to grasp and operate the toothbrush. It is preferable that head 110, neck section 130, and handle section are each made of synthetic resin. Head 110, neck section 130, and handle section may each be combined as separate pieces, or all or part of them may be molded as a single piece.

In the following description, as shown in FIG. 1, the side of the head 110 that is connected to the neck 130 is referred to as the rear side, the tip side of the head 110 that is not connected to anything is referred to as the front side, and the direction connecting the front and rear sides of the head 110 is defined as the extension direction of the head and is referred to as the front-to-back direction. Furthermore, the side of the head 110 that is closer to the right hand when viewed from the front is referred to as the right side, the side of the head 110 that is closer to the left hand when viewed from the front is referred to as the left side, and the direction perpendicular to the extension direction of the head 110 is referred to as the left-to-right direction. Furthermore, the side of the head 110 on which the brush part 120 is embedded is referred to as the upper side, the side on which the brush part 120 is not embedded is referred to as the lower side, and the direction connecting the upper and lower sides, which is perpendicular to both the front-to-back direction and the left-to-right direction, is referred to as the up-down direction. These directions are shown in each figure using Cartesian coordinates.

(head)
The head 110 is a part located at the tip in the front-to-rear direction of the toothbrush 100. When viewed from the front, the head 110 is integrally formed with a central portion 111, a right portion 112 located to the right of the central portion 111, and a left portion 113 located to the left of the central portion 111. A front surface 110fr is formed on the front side of the head 110.

In the head 110, the central portion 111 has a central buried surface 111a that is parallel to the front-to-back and left-to-right plane and has a roughly rectangular outer shape with the front-to-back direction as the longitudinal direction in a plan view. The right side portion 112 has a right buried surface 112a that is an inclined surface extending from the right long side of the central portion 111 toward the central buried surface 111a and has a roughly rectangular outer shape with the front-to-back direction as the longitudinal direction in a plan view. The left side portion 113 has a left buried surface 113a that is an inclined surface extending from the left long side of the central portion 111 toward the central buried surface 111a and has a roughly rectangular outer shape with the front-to-back direction as the longitudinal direction in a plan view. The right buried surface 112a and the left buried surface 113a are inclined at angles that are symmetrical to the central buried surface 111a in a front-to-back view.

(Brush part)
The brush part 120 has a central brush part 121 embedded in the central embedded surface 111a of the central part 111 of the head 110, a right brush part 122 embedded in the right embedded surface 112a of the right part 112 of the head 110, and a left brush part 123 embedded in the left embedded surface 113a of the left part 113 of the head 110.

In the brush section 120, the central brush section 121 is embedded perpendicular to the central embedded surface 111a. The right brush section 122 is embedded perpendicular to the right embedded surface 112a. The left brush section 123 is embedded perpendicular to the left embedded surface 113a.

In addition, when viewed from the front, the tips of the right brush section 122 and the left brush section 123 form brushing surfaces of the same height, while the tip of the central brush section 121 forms a brushing surface that is lower than the right brush section 122 and the left brush section 123.

As a result, in the head 110, the central brush part 121 stands upright in the vertical direction, and the right brush part 122 and the left brush part 123 are each inclined toward the central brush part 121, with the tips forming their brushing surfaces positioned higher than the tip of the central brush part 121. The inclination angle θ of each of the right brush part 122 and the left brush part 123 toward the central brush part 121, as shown in Figure 2 (A), is preferably in the range of 5°≦θ≦45°.

Each of the central brush part 121, right brush part 122, and left brush part 123 of the brush part 120 has a pair of hair bundle groups arranged with the front-to-back direction as the longitudinal direction. Specifically, the central brush part 121 has a front hair bundle group 121a embedded toward the front of the head 110 and a rear hair bundle group 121b embedded a predetermined distance rearward from the front hair bundle group 121a. The right brush part 122 has a front hair bundle group 122a embedded toward the front of the head 110 and a rear hair bundle group 122b embedded a predetermined distance rearward from the front hair bundle group 122a. The left brush part 123 has a front hair bundle group 123a embedded toward the front of the head 110 and a rear hair bundle group 123b embedded a predetermined distance rearward from the front hair bundle group 123a.

As shown in the respective figures, each of the front hair bundle group 121a and the rear hair bundle group 121b is composed of a pair of hair bundles arranged in the front-to-back direction. Each of the front hair bundle group 122a and the rear hair bundle group 122b, and the front hair bundle group 123a and the rear hair bundle group 123b is composed of two pairs (four bundles) of hair bundles, two bundles each in the front-to-back and left-to-right directions. While each of the front hair bundle group 121a and the rear hair bundle group 121b is composed of a pair of hair bundles arranged in the front-to-back direction as shown in the respective figures, each hair bundle group may also be composed of two pairs (four bundles) of hair bundles, two bundles each in the front-to-back and left-to-right directions.

As shown particularly in FIG. 3, front hair bundle groups 121a, 122a, and 123a are each positioned at the same position closer to the front in the front-to-back direction, thereby constituting front brush group 120a, which is arranged with the left-to-right direction as its longitudinal direction. Rear hair bundle groups 121b, 122b, and 123b are each positioned at the same position closer to the rear in the front-to-back direction, thereby constituting rear brush group 120b, which is arranged with the left-to-right direction as its longitudinal direction.

When brushing the cheek tooth surface, the specified distance between the front brush group 120a and the rear brush group 120b is preferably large enough to accommodate one or more teeth, and is preferably large enough so that the brushing surfaces of both the front brush group 120a and the rear brush group 120b do not come into contact with any one tooth. On the other hand, when brushing the lingual tooth surface, the specified distance between the front brush group 120a and the rear brush group 120b may be close to each other.

Furthermore, as shown in FIG. 2(B), it is preferable that the dimension t1 from the tips of the front hair bundle group 123a and the rear hair bundle group 123b of the left brush part 123 to the central buried surface 111a is larger than the dimension t2 from the tips of the front hair bundle group 121a and the rear hair bundle group 121b of the central brush part 121 to the central buried surface 111a. Similarly, it is preferable that the dimension t1 from the tips of the front hair bundle group 122a and the rear hair bundle group 122b of the right brush part 122 to the central buried surface 111a is larger than the dimension t2 from the tips of the front hair bundle group 121a and the rear hair bundle group 121b of the central brush part 121 to the central buried surface 111a.

The toothbrush 100 according to the first embodiment of the present invention, which has the above-described configuration, is characterized in that the brush section 120 is composed of a combination of a front brush group 120a and a rear brush group 120b, the front brush group 120a is configured to include combinations of a front bristle group 121a and a front bristle group 122a, and a front bristle group 121a and a front bristle group 123a, and the rear brush group 120b is configured to include combinations of a rear bristle group 121b and a rear bristle group 122b, and a rear bristle group 121b and a rear bristle group 123b, each combination corresponding to a combination of a working section and a stabilizing section, which will be described later.

The following describes the effects of the toothbrush 100 based on a preferred example of use of the toothbrush 100 according to the first embodiment of the present invention, with reference to Figure 4 as well.

As an example, let us take the brushing of the lower left dentition 200, as shown schematically in Figure 4(A). Figure 4(A) is a view from the occlusal surface of a toothbrush according to the first embodiment of the present invention placed against the buccal surface of the lower left dentition. The toothbrush 100 is used in the oral cavity so that the brushing surface of the brush head 120 faces the buccal side (front side) of the dentition 200, which includes teeth 210, 220, 230, 240, and 250. However, in this example, the toothbrush 100 is held in the user's right hand, and the brushing surface of the brush head 120 faces the buccal side (front side) of the dentition 200. In the following descriptions of each embodiment, unless otherwise specified, the toothbrush 100 is also assumed to be held in the user's right hand.

As shown by the solid lines in Figure 4(A), first, the rear brush group 120b is brought into contact with the tooth 250 at the front of the tooth row and positioned at the desired position. Then, while keeping the rear brush group 120b in position, the front brush group 120a is placed against the tooth 230 at the back of the tooth row, and the handle is operated to move the front brush group 120a in the direction and within the range of motion indicated by arrow 301b to brush the tooth 230. Next, the toothbrush 100 is moved to the position shown by the dotted lines in Figure 4(A), the rear brush group 120b is brought into contact with the tooth 240 in the tooth row, and the front brush group 120a is placed against the tooth 220 further back in the tooth row and moved in the direction and within the range of motion indicated by arrow 301a to brush the tooth 220.

In the above operation, it is preferable to use the contact point between the rear brush group 120b and the teeth 250 as a fulcrum, and to operate the handle with the intention of influencing the movement of the front brush group 120a rather than applying force to the rear brush group 120b. Furthermore, it is preferable to use the tactile sensation of the rear brush group 120b transmitted to the teeth or gums to grasp the position and posture of the front brush group 120a relative to the teeth 210-250 in the dentition 200.

In this way, with the toothbrush 100 according to the first embodiment, when brushing the cheek side (front side) or tongue side (back side) of the dentition, the front brush group 120a of the brush unit 120 acts as a working part that brushes the desired tooth in the dentition, while the rear brush group 120b of the brush unit 120 acts as a stabilizing part that guides the front brush group 120a to the desired tooth in response to the user's operation, making it easier to brush in a stable state. The toothbrush 100 according to the first embodiment is particularly suitable for brushing the cheek side of the dentition.

Furthermore, when brushing, the toothbrush 100 is moved back and forth in small increments in the direction of extension within the narrow oral cavity. However, as shown by the positional relationship between the solid and dotted lines in Figure 4(A), the positions of the front brush group 120a and the rear brush group 120b are offset, so excessive brush pressure is not concentrated on the protruding portions of the dentition 200, and the toothbrush 100 can be brushed stably while preventing pitching. In other words, even if the front brush group 120a and the rear brush group 120b are used with more brush pressure than necessary, which is not the preferred use example, by distributing the brush pressure to two locations on the dentition 200 where the front brush group 120a and the rear brush group 120b contact, it is possible to avoid the risk of excessive brush pressure from being concentrated on a specific protruding portion of the dentition 200 during brushing. Arrow 301a in Figure 4(A) indicates the direction and magnitude of the reciprocal movement of toothbrush 100 over a distance of one tooth at the position of toothbrush 100 indicated by the dotted line, and arrow 301b in Figure 4(A) indicates the direction and magnitude of the reciprocal movement of toothbrush 100 over a distance of one tooth at the position of toothbrush 100 indicated by the solid line. As such, since the tangent direction to the tooth row is different at each position, the direction of movement is also different.

Next, Figure 4(B) shows a cross-sectional view taken along line B-B in Figure 4(A). As shown in Figure 4(B), the front bristle bundles 121a of the central brush unit 121 are brought into contact with or near the maximum prominence 220X, which is the most bulging part on the cheek side 221 of the tooth 220, and positioned accordingly. Then, while keeping the front bristle bundles 121a positioned, the front bristle bundles 123a of the left brush unit 123 are placed against the surface 221A below the maximum prominence 220X and between the gum lines, which is prone to soiling, and the handle is operated to move the front bristle bundles 123a back and forth along the direction of the tooth row, thereby brushing the surface 221A.

In the above operation, the contact point between the front hair bundle group 121a and the teeth 220 acts as a stabilizing point (fulcrum), and the operation of the handle can be performed with the intention of reflecting the movement of the front hair bundle group 123a rather than applying force to the front hair bundle group 121a.

In other words, the front bristle bundles 121a of the central brush part 121, which is the stabilizing part, act as a fulcrum, preventing the head 110 of the toothbrush 100 from rolling, thereby preventing the toothbrush 100 from wobbling during rotation. When the head 110 of the toothbrush 100 is moved back and forth during brushing, the brushing surface of the front bristle bundles 123a of the left brush part 123, which is the working part, always contacts the front side of the teeth in a constant position.

Furthermore, in this case, when the head 110 swings around the contact point between the front hair bundle group 121a and the tooth 220 as a fulcrum, the front hair bundle group 122a supports the tooth 220 from its maximum prominence portion 220X to its tip end side 221B, thereby acting as a stabilizing part that reduces rotational wobble of the head 110.

In addition, during this operation, as in the case shown in Figure 4(A), the tactile sensation of the front bristle bundles 121a transmitted to the teeth or gums can be used to brush the toothbrush 100 at the position of the maximum prominence 220X on the cheek side 221 of the tooth 220 while feeling it in the hand holding the toothbrush 100.

In this way, the toothbrush 100 according to the first embodiment is configured so that, when the brush unit 120 brushes the cheek side (front side) of the teeth, the front bristle group 123a of the left brush unit 123 acts as a working unit that brushes the teeth in the dentition, and the front bristle group 121a of the central brush unit 121 of the brush unit 120 acts as a stabilizing unit that guides the front brush group 120a to the correct posture and target position relative to the front side of the teeth in response to user operation, making it easier to brush in a stable state.

Furthermore, as shown in particular in FIG. 2(A), the toothbrush 100 according to the first embodiment is configured such that the front bristle bundle group 123a, which serves as the working portion, is inclined toward the front bristle bundle group 121a, which serves as the stabilizing portion, and has a brushing surface that is higher than the front bristle bundle group 121a, thereby achieving the following effects. Specifically, as illustrated in FIG. 4(B), the cheek side 221 of the tooth 220 has a curved convex shape with the maximum contoured portion 220X as its apex, and the surface portions extending above (toward the tip) and below (toward the gums) from that apex. However, with the toothbrush 100 configured as described above, when the front bristle bundle group 121a is positioned at or near the maximum contoured portion 220X, the brushing surface of the front bristle bundle group 123a contacts the surface 221A of the tooth 220 below (toward the gums) the maximum contoured portion 220X in a substantially perpendicular manner.

In this case, the toothbrush 100 has an inclination angle θ of each of the right brush portion 122 and the left brush portion 123 relative to the central brush portion 121 within the range of 5°≦θ≦45°. This allows it to adapt to the tooth shapes of a wide variety of users, regardless of gender or age, and when the front bristle bundle group 121a is positioned at or near the maximum contoured portion 220X, the brushing surface of the front bristle bundle group 123a can be brought into contact with the tooth surface 221A below the maximum contoured portion 220X (towards the gums) in a substantially perpendicular position.

This allows the user of the toothbrush 100 to reliably remove plaque that has accumulated between the surface 221A and the gums 300, while feeling the sensation that the brush head 120 is brushing the teeth in the appropriate position. As a result, excessive toothbrushing, i.e., friction caused by excessive brushing pressure or excessive brushing frequency, is suppressed, preventing wedge-shaped defects and damage to the gums.

Furthermore, as shown in Figure 4(B), if the user of the toothbrush 100 uses the toothbrush so that at least the front bristle bundle group 121a and the front bristle bundle group 122a are kept in contact with the teeth during brushing, the front bristle bundle group 121a can maintain contact with the teeth 220 and act as a stabilizing part (buffer) against brush pressure. This prevents the brushing surface of the front bristle bundle group 123a from coming into contact with the surface 221A with excessive brush pressure.

Note that in the explanation with reference to Figures 4(A) and (B), brushing of the lower right dentition 200 was used as an example, but the toothbrush 100 can be used to brush any part of the upper or lower dentition. In this case, the correspondence between the groups of bristle bundles that act as working parts and stabilizing parts is as follows:

When targeting the teeth of the right mandible and left maxilla, the front bristle bundle group 123a of the left brush part 123 acts as the working part, and the front bristle bundle group 121a of the central brush part 121 and the front bristle bundle group 122a of the right brush part 122 act as the stabilizing part.

When targeting the left lower jaw and right upper jaw dentition, as in the case shown in Figure 4(B), the front bristle bundle group 122a of the right brush part 122 acts as the working part, and the front bristle bundle group 121a of the central brush part 121 and the front bristle bundle group 123a of the left brush part 123 act as the stabilizing part.

As described above, the toothbrush 100 according to the first embodiment of the present invention enables proper brushing that avoids the risk of adverse effects on all teeth, dentition, and gums, both above and below.

Note that the front brush group 120a and rear brush group 120b, which constitute the working section and stabilizing section when viewed from the front to back, are perpendicular when viewed from the top to bottom to the central brush section 121, right brush section 122, and left brush section 123 of the brush section 120, which constitute the working section and stabilizing section when viewed from the left to right. However, they may intersect at any angle as long as the above-described effects are achieved.

(Modification 1 of the First Embodiment)
In the above description, the toothbrush 100 according to the first embodiment of the present invention is described as having each of the front bristle bundle group 122a and the rear bristle bundle group 122b, and the front bristle bundle group 123a and the rear bristle bundle group 123b, consisting of four bristle bundles, with two bristle bundles arranged in the front-to-back direction and two bristle bundles arranged in the left-to-right direction, as shown in Fig. 3. However, as shown in Figs. 5(A) and 5(B) , the toothbrush 100A according to the first modification of the first embodiment may have each of the front bristle bundle group 122a and the rear bristle bundle group 122b, and the front bristle bundle group 123a and the rear bristle bundle group 123b of the toothbrush 100 shown in Fig. 3, consisting of six bristle bundles, with two bristle bundles arranged in the front-to-back direction and three bristle bundles arranged in the left-to-right direction.

Furthermore, as shown in Figures 6(A) and (B), toothbrush 100B according to another variant 1 of the first embodiment may be configured such that each of the front bristle bundle group 122a and rear bristle bundle group 122b, and the front bristle bundle group 123a and rear bristle bundle group 123b of toothbrush 100 shown in Figure 3, is composed of two bristle bundles, with two bristle bundles arranged in the front-to-rear direction and one bristle bundle arranged in the left-to-right direction.

In short, the number of bristle tufts that make up the bristle tuft group of the brush that functions as the working or stabilizing portion of the present invention may be any number.

Furthermore, in the above description, the brush that functions as the working or stabilizing part of the present invention is described as being composed of a group of bristle bundles having multiple bristle bundles, but it may also be composed of a single bristle bundle. Furthermore, the head 110 as the head of the present invention and the brush that functions as the working or stabilizing part of the present invention are not limited by their front-to-back or left-to-right dimensions. It should be noted that toothbrushes 100A and 100B according to Variation 1 of the first embodiment are particularly suitable for brushing the cheek side of the dentition.

(Modification 2 of the First Embodiment)
In the above explanation, the toothbrush 100 according to the first embodiment of the present invention is configured so that the front bristle bundle group 122a of the right brush portion 122 of the brush portion 120 or the front bristle bundle group 123a of the left brush portion 123 can function as the working portion, and the front bristle bundle group 121a of the central brush portion 121 of the brush portion 120 can function as the stabilizing portion, but the stabilizing portion does not have to be a bristle bundle group or a brush composed of bristle bundles.

That is, Figures 7(A), (B), and 8 show toothbrush 100C, a modified version of toothbrush 100, in which a stopper 141 made of silicone material is provided as a stabilizing part on the central embedded surface 111a of the central part 111 instead of the central brush part 121.

As shown in the figures, instead of the central brush portion 121 of the toothbrush 100C according to Variation 2 of the first embodiment, the stopper 141 of the toothbrush 100 shown in Figure 3 has a front stopper 141a embedded in the front of the head 110 and a rear stopper 141b embedded at a predetermined distance rearward from the front stopper 141a.

Here, it is preferable that the dimension t1 from the tips of the front hair bundle group 122a and the rear hair bundle group 122b of the right brush part 122 to the central buried surface 111a be greater than the dimension t2 from the tips of the front stopper 141a and the rear stopper 141b of the stopper 141 to the central buried surface 111a. Similarly, it is preferable that the dimension t1 from the tips of the front hair bundle group 123a and the rear hair bundle group 123b of the left brush part 123 to the central buried surface 111a be greater than the dimension t2 from the tips of the front stopper 141a and the rear stopper 141b of the stopper 141 to the central buried surface 111a.

The front stopper 141a and rear stopper 141b preferably have the same dimensions and number as the front bristle bundle group 122a and rear bristle bundle group 122b, respectively, but the tip shape is preferably curved as shown in the figure to avoid damaging the teeth or gums. Furthermore, the material properties such as elasticity and flexibility are preferably similar to those of the other brush parts that function as working parts, to make it easier to maintain appropriate brush pressure during use. Furthermore, although the material for stopper 141 is described as being silicone, any synthetic resin material such as polypropylene or any other material can be used as long as it is considered to be hygienic when placed in the oral cavity.

In short, the stabilizing part of the present invention need only be configured to guide and stabilize the brush, which acts as the working part, so that it brushes the teeth in the correct posture and while maintaining the target position, and it may also be realized as a part that does not have a brushing function. The toothbrush 100C according to Variation 2 of the first embodiment is particularly suitable for brushing the cheek side of the dentition.

(Third Modification of the First Embodiment)
In the above description, the toothbrush 100 according to the first embodiment of the present invention has a head 110 in which a central portion 111, a right side portion 112, and a left side portion 113 are integrally formed, but the head 110 may also have only the central portion 111 and either the right side portion 112 or the left side portion 113.

That is, as shown in Figures 9(A) and 9(B), toothbrush 100D according to variant 3 of the first embodiment is the toothbrush 100 shown in Figure 3, with the left side portion 113 removed from the head 110, and only the center portion 111 and right side portion 112 remaining.

The toothbrush 100D according to variant 3 of the first embodiment has the front bristle bundles 122a of the right brush part 122 functioning as the working part, and the front bristle bundles 121a of the central brush part 121 functioning as the stabilizing part, making it ideal for brushing the cheek sides of the teeth on the right upper jaw and left lower jaw.

On the other hand, when the toothbrush has a central portion 111 and a left portion 113, the front bristle bundles 123a of the left brush portion 123 act as the working portion, and the front bristle bundles 121a of the central brush portion 121 act as the stabilizing portion, making it suitable for brushing the cheek sides of the dentition on the left maxilla and right mandible. The toothbrush 100D according to variant 3 of the first embodiment is particularly suitable for brushing the cheek sides of the dentition.

In short, the combination of the working unit and the stabilizing unit of the present invention is not limited by the specific number or arrangement thereof.
Furthermore, in the above description, the front brush group 120a of the brush unit 120 acts as a working unit that brushes the desired tooth in the dentition, and the rear brush group 120b of the brush unit 120 acts as a stabilizing unit that guides the front brush group 120a to the desired tooth in response to the user's operation and makes it easier to brush in a stable state, but the front brush group 120a of the brush unit 120 may act as a stabilizing unit and the rear brush group 120b of the brush unit 120 may act as a working unit in response to the user's operation. This also applies to each embodiment described below.

Second Embodiment
Fig. 10(A) is a right side view showing the configuration of a toothbrush according to a second embodiment of the present invention, Fig. 10(B) is a front view showing the configuration of the toothbrush according to the second embodiment, and Fig. 10(C) is a plan view showing the configuration of the toothbrush according to the second embodiment. However, the same reference numerals are used for components that are the same as or equivalent to those in Figs. 1 to 9, and detailed descriptions of common components will be omitted.

The toothbrush 101 according to the second embodiment is a toothbrush designed to prevent the handle from hitting the tips of the front teeth, particularly when brushing the lingual surfaces of the dentition.
In toothbrush 101 according to the second embodiment, head 150 has a polygonal outer shape with the longitudinal direction in the front-to-rear direction in a plan view, the left-to-right dimension of the front being smaller than the left-to-right dimension of the rear, and only has embedded surface 150a that is parallel to the plane formed by the front-to-rear and left-to-right directions.

The head 150 has a brush section 151 embedded in the embedding surface 150a. The brush section 151 has a pair of bristle bundles, a front bristle bundle group 151a and a rear bristle bundle group 151b, which are arranged in the front-to-rear direction and embedded perpendicular to the embedding surface 150a.

The front hair bundle group 151a is a hair bundle group embedded toward the front of the head 150, and is composed of four hair bundles, two in each of the front-to-back and left-to-right directions. The rear hair bundle group 151b is a hair bundle group embedded toward the rear of the head 150, at a predetermined distance rearward from the front hair bundle group 151a. The rear hair bundle group 151b is composed of eight hair bundles, two in each of the front-to-back directions and four in each of the left-to-right directions. Furthermore, the rear hair bundle group 151b includes a right rear hair bundle group 152b, which is composed of four hair bundles, two in each of the front-to-back and left-to-right directions, on the right side toward the rear of the head 150. The rear hair bundle group 151b also includes a left rear hair bundle group 153b, which is composed of four hair bundles, two in each of the front-to-back and left-to-right directions, on the left side toward the rear of the head 150.

The hair bundles that make up the front hair bundle group 151a and the rear hair bundle group 151b are spaced at equal intervals in both the front-to-back and left-to-right directions. Therefore, in terms of left-to-right dimensions, the rear hair bundle group 151b is larger than the front hair bundle group 151a, and the planar shape of the embedded surface 150a corresponds to the difference in left-to-right dimensions of the front hair bundle group 151a and the rear hair bundle group 151b.

The toothbrush 101 according to the second embodiment of the present invention, which has the above-described configuration, has a brush section 151 formed by a combination of a front bristle bundle group 151a and a rear bristle bundle group 151b, thereby achieving the same effects as the combination of the front bristle bundle group 120a and the rear bristle bundle group 120b of the toothbrush 100 according to the first embodiment, as described with reference to Figure 4 (A). That is, in the brush section 151, when brushing the tongue side (back side) of the dentition, the front bristle bundle group 151a acts as a working part that brushes the desired tooth in the dentition, and the rear bristle bundle group 151b acts as a stabilizing part that guides the front bristle bundle group 151a to the desired tooth in response to the user's operation, making it easier to brush in a stable state.

This allows for proper brushing, reducing the risk of adverse effects on the teeth, dentition, and gums.

Furthermore, the toothbrush 101 according to the second embodiment has a larger left-right dimension in the rear bristle bundle group 151b than in the front bristle bundle group 151a, and the bristle bundle group has a generally triangular outer shape, thereby achieving the following effects: When brushing the tongue side of the teeth of the left upper jaw and right lower jaw, the front bristle bundle group 151a acts as the working part, and the right rear bristle bundle group 152b of the rear bristle bundle group 151b acts as the stabilizing part. On the other hand, when brushing the teeth of the right upper jaw and left lower jaw, the front bristle bundle group 151a acts as the working part, and the left rear bristle bundle group 153b of the rear bristle bundle group 151b acts as the stabilizing part. This reduces the risk of only the front bristle bundles 151a, which act as the working part of the brush head 120, coming into contact with the teeth when using the toothbrush 101, and makes it easier to achieve optimal brushing by utilizing the combination of the working part and stabilizing part, and without the neck part 130 and handle part (not shown) of the toothbrush interfering with the tips of the front teeth.

(Variation 1 of the second embodiment)
In the above description, the toothbrush 101 according to the second embodiment of the present invention has an embedded surface 150a in which the front bristle bundle group 151a and the rear bristle bundle group 151b are embedded, which forms a parallel surface to the plane formed by the front-to-back and left-to-right directions, but the embedded surface may also be curved on both the left and right sides.

That is, Figures 11(A) and (B) show a toothbrush 101A according to Variation 1 of the second embodiment. The toothbrush 101A has a concave curved surface with both left and right sides bent. In this variation, the embedded surface of the head 150 has a polygonal outer shape in plan view. This toothbrush 101A has a central embedded surface 111a that is parallel to the front-to-back and left-to-right plane. It also has a right embedded surface 112a that is an inclined surface extending from the right long side of the central embedded surface 111a toward the central embedded surface 111a. The right embedded surface 112a has a roughly trapezoidal outer shape with the front-to-back direction as the longitudinal direction in plan view. It also has a left embedded surface 113a that is an inclined surface extending from the left long side of the central embedded surface 111a toward the central embedded surface 111a. The left embedded surface 113a has a roughly trapezoidal outer shape with the front-to-back direction as the longitudinal direction in plan view.

The front hair bundle group 151a of the brush part 151 is provided only on the central buried surface 111a, while the rear hair bundle group 151b is provided from the central buried surface 111a to both the right buried surface 112a and the left buried surface 113a. Furthermore, the rear hair bundle group 151b is arranged two bundles in the front-to-back direction on the central buried surface 111a and the right buried surface 112a on the rear right side of the head 150, and includes a right rear hair bundle group 152b consisting of four hair bundles arranged two bundles in the front-to-back direction on the right buried surface 112a. Furthermore, the rear hair bundle group 151b is arranged two bundles in the front-to-back direction on the central buried surface 111a and the left buried surface 113a on the rear left side of the head 150, and includes a left rear hair bundle group 153b consisting of four hair bundles arranged two bundles in the front-to-back direction on the left buried surface 113a.

As a result, of the hair bundle groups that make up the rear hair bundle group 151b, the hair bundle groups embedded in the right-side buried surface 112a and the left-side buried surface 113a are inclined toward the hair bundle group embedded in the central buried surface 111a when viewed in the front-to-back direction, as shown in Figure 11.

The toothbrush 101A according to Variation 1 of the second embodiment, having the above-described configuration, not only achieves the same effects as the toothbrush 101 of the second embodiment, but also achieves the following effects. That is, when targeting the lingual side of the teeth on the left maxilla and right mandible, the front bristles 151a function as the working part, and the right rear bristles 152b of the rear bristles 151b function as the stabilizing part. On the other hand, when targeting the teeth on the right maxilla and left mandible, the front bristles 151a function as the working part, and the left rear bristles 153b of the rear bristles 151b function as the stabilizing part. This reduces the risk that only the front bristles 151a, which serve as the working part of the brush head 120, will come into contact with the teeth when using the toothbrush 101. This utilizes a combination of the working part and the stabilizing part, and allows for more stable brushing by holding the most prominent part of the lingual side of the teeth without interference from the tips of the front teeth with the neck part 130 of the toothbrush.

The bristle bundles in the rear bristle bundle group 151b, embedded in the central embedded surface 111a as in the toothbrush 100 of the first embodiment, may have a lower brushing surface than the bristle bundles embedded in the right embedded surface 112a and the left embedded surface 113a, and the bristle bundles embedded in the right embedded surface 112a and the left embedded surface 113a may be inclined at an angle θ in the range of 5°≦θ≦45° relative to the bristle bundles embedded in the central embedded surface 111a. In this case, the toothbrush 101A can be used to achieve the same effects as the first embodiment. The toothbrush 101A according to Variation 1 of the second embodiment is preferably used for brushing the tongue side of the dentition.

(Modification 2 of the Second Embodiment)
In the above description, the toothbrush 101 according to the second embodiment of the present invention is described as having each of the bristle bundles constituting the front bristle bundle group 151a and the rear bristle bundle group 151b arranged at equal intervals in both the front-to-back and left-to-right directions, but the each of the bristle bundles constituting the front bristle bundle group and the rear bristle bundle group may also be arranged at different intervals in both or either the front-to-back and left-to-right directions.

That is, as shown in Figures 12(A), (B), and (C), toothbrush 101B according to variant 2 of the second embodiment has bristle bundles that make up the front bristle bundle group and the rear bristle bundle group arranged at different intervals in the left-right direction. Toothbrush 101B according to variant 2 of the first embodiment has right-side brush portion 152 embedded on the right side of embedding surface 150a, which has a generally trapezoidal planar shape, of head 150, and left-side brush portion 153 embedded on the left side.

The right brush part 152 has a front group of hair bundles 152a embedded near the front of the head 150, and a rear group of hair bundles 152b embedded near the rear of the head 150 at a predetermined distance rearward from the front group of hair bundles 152a. The left brush part 153 has a front group of hair bundles 153a embedded near the front of the head 150, and a rear group of hair bundles 153b embedded near the rear of the head 150 at a predetermined distance rearward from the front group of hair bundles 153a.

Front hair bundle group 152a and front hair bundle group 153a are each a group of hair bundles embedded toward the front of head 150, and are composed of two hair bundles arranged in the front-to-back direction, two bundles each in the left-to-right direction.

Each of rear hair bundle groups 152b and 153b is a group of hair bundles embedded toward the rear of the head 150, and is composed of two hair bundles arranged in the front-to-back direction, two bundles each, and one bundle each in the left-to-right direction.

Furthermore, as shown in Figure 12(C), of the hair bundles arranged in the front-to-back direction that make up the front hair bundle group 152a, the rear hair bundle 152a2 is located to the right of the front hair bundle 152a1. Of the hair bundles arranged in the front-to-back direction that make up the rear hair bundle group 152b, the front hair bundle 152b1 is located to the right of the rear hair bundle 152a2 of the front hair bundle group 152a, and the rear hair bundle 152b2 is located to the right of the front hair bundle 152b1.

Similarly, of the hair bundles arranged in the front-to-back direction that make up the front hair bundle group 153a, the rear hair bundle 153a2 is located to the left of the front hair bundle 153a1. Of the hair bundles arranged in the front-to-back direction that make up the rear hair bundle group 153b, the front hair bundle 153b1 is located to the left of the rear hair bundle 153a2 of the front hair bundle group 153a, and the rear hair bundle 153b2 is located to the left of the front hair bundle 153b1.

As a result, the hair bundles that make up the front hair bundle group 152a and the rear hair bundle group 152b of the right brush part 152 form rows that gradually slope to the right as they move from the front to the rear. Similarly, the hair bundles that make up the front hair bundle group 153a and the rear hair bundle group 153b of the left brush part 153 form rows that gradually slope to the left as they move from the front to the rear.

In other words, the dimensions of the right brush part 152 and the left brush part 153 increase overall on the embedded surface 150a from the front end to the rear end of the head part 150 in the left-right direction, which is perpendicular to the extension direction of the head part 150.

The toothbrush 101B according to Variation 2 of the second embodiment, with its configuration described above, not only achieves the same effects as the toothbrush 101 according to the second embodiment, but also achieves the following effects. Specifically, the toothbrush 101B according to Variation 2 of the second embodiment has bristles that form the right brush section 152 in a row that gradually tilts to the right as it moves from the front to the rear, so that the handle of the toothbrush does not hit the tips of the front teeth when brushing the lingual side of the teeth on the right mandible and left maxilla. This compensates for the tilt of the right brush section 152 that occurs when the head section 150 is inserted into the oral cavity with its longitudinal axis tilted to the left, and allows each bristle tuft that forms the right brush section 152 to contact the line connecting the cervical regions of the teeth in a position that is nearly parallel to the line. This makes it possible to achieve optimal brushing using a combination of a working section and a stabilizing section in a more stable manner.

Similarly, toothbrush 101B according to variant 2 of the second embodiment has bristles that gradually tilt to the left as they move from front to back, so that the handle of the toothbrush does not come into contact with the tips of the front teeth when brushing the lingual side of the dentition of the lower left and right jaws. This compensates for the tilt of left brush part 153 that occurs when head 150 is inserted into the mouth with the head tilted to the right, and allows each bristle that makes up left brush part 153 to contact the line connecting the cervical parts of the dentition in a position that is nearly parallel to the line. This makes it possible to achieve more stable, suitable brushing using a combination of working part and stabilizing part. Toothbrush 110B according to variant 2 of the second embodiment is more suitable for brushing the lingual side of the dentition.

(Modification 3 of the second embodiment)
In the above explanation, the toothbrush 101 according to the second embodiment of the present invention is configured so that the front bristle bundle group 151a of the brush part 151 can function as a working part and the rear bristle bundle group 151b of the brush part 151 can function as a stabilizing part, but the stabilizing part does not have to be a bristle bundle group or a brush composed of bristle bundles.

That is, as shown in Figures 13(A) and 13(B), toothbrush 101C according to variant 3 of the second embodiment has a rectangular shape for the embedded surface 150a of head 150 with the longitudinal direction extending in the front-to-back direction in plan view, and a stopper 142 made of silicone material is provided in place of rear bristle bundle group 151b.

In toothbrush 101C, stoppers 142 preferably have the same dimensions and number as front bristle bundles 151a, but the tip shape is preferably curved as shown in the figure to avoid damaging teeth or gums. Furthermore, material properties such as elasticity and flexibility are preferably similar to those of the other brush parts that function as working parts, to make it easier to maintain appropriate brush pressure during use. While stoppers 142 are described as being made of silicone, any synthetic resin material such as polypropylene or other material can be used as long as it is considered hygienic when placed in the oral cavity.

In short, the stabilizing part of the present invention only needs to have a configuration that can guide and stabilize the brush, which acts as the working part, so that it brushes while maintaining the correct posture and target position relative to the front side of the teeth, and it may also be realized as a configuration that does not have a brushing function. Note that toothbrush 101C according to variation 3 of the second embodiment is particularly suitable for brushing the cheek side of the dentition.

Furthermore, as shown in Figures 13(C) and (D), toothbrush 101D according to another variation 3 of the second embodiment may be configured with bristle tuft group 124 provided in the gap between front bristle tuft group 151a and stopper 142. Bristle tuft group 124 of toothbrush 101D has a brushing surface that is lower in height than the brushing surface of front bristle tuft group 151a and the top of stopper 142. The height of the brushing surface of bristle tuft group 124 is preferably less than half the brushing surface of front bristle tuft group 151a. This allows for efficient tooth brushing without interfering with optimal brushing using the combination of the working section and the stabilizing section. Furthermore, toothbrush 101D according to another variation 3 of the second embodiment is particularly suitable for brushing the posterior surface of the posteriormost part of the dentition, in addition to brushing the cheek side of the dentition.

Note that bristle bundles such as bristle bundle 124 may be provided in toothbrush 100 according to the first embodiment and toothbrushes 100A to 100D according to each of the variations of the first embodiment.

(Third embodiment)
Fig. 14(A) is a right side view showing the configuration of toothbrush 102 according to the third embodiment of the present invention, Fig. 14(B) is a bottom view showing the configuration of toothbrush 102 according to the third embodiment, and Fig. 14(C) is a cross-sectional view taken along the line D-D of Fig. 14(B). However, the same reference numerals are used for components that are the same as or equivalent to those in Figs. 1 to 13, and detailed descriptions of common components will be omitted.

The toothbrush 102 according to the third embodiment is a toothbrush designed to prevent the handle of the toothbrush from interfering with the incisal edges of the front teeth when brushing the tongue side.
The toothbrush 102 according to the third embodiment has a head 150 that has a rectangular shape with the longitudinal direction in the front-to-back direction when viewed from above, and has only an embedded surface 150a that is parallel to the plane formed by the front-to-back and left-to-right directions.

Furthermore, in the toothbrush 102, the handle portion 160 is positioned above the embedded surface 150a in the vertical direction and shifted to the left of the left edge of the embedded surface 150a in the horizontal direction, so that the embedded surface 150a faces the handle portion 160. The head 150 and handle portion 160 are connected by the neck portion 130. The neck portion 130 extends diagonally downward and diagonally right from the tip 161 of the handle portion 160, to which the rear end 132 is connected, and the tip 131 is fixed to the left side surface 150c of the head 150.

The head 150 has a brush section 151 embedded in the embedding surface 150a. The brush section 151 has a pair of bristle bundles, a front bristle bundle group 151a and a rear bristle bundle group 151b, which are arranged in the front-to-rear direction and embedded perpendicular to the embedding surface 150a.

The front hair bundle group 151a is a hair bundle group embedded toward the front of the head 150, and is composed of four hair bundles, two in each of the front-to-back and left-to-right directions. The rear hair bundle group 151b is a hair bundle group embedded toward the rear of the head 150, at a predetermined distance rearward from the front hair bundle group 151a, and is composed of four hair bundles, two in each of the front-to-back and left-to-right directions.

The hair bundles that make up the front hair bundle group 151a and the rear hair bundle group 151b are arranged at equal intervals in both the front-to-back and left-to-right directions. Therefore, the front hair bundle group 151a and the rear hair bundle group 151b have the same shape.

The toothbrush 102 according to the third embodiment of the present invention, which has the above-described configuration, has a head 150 that includes a brush section 151, thereby achieving the same effects as the combination of the front brush group 120a and rear brush group 120b of the toothbrush 100 according to the first embodiment, as described with reference to Figure 4 (A). That is, in the brush section 151, when brushing the tongue side (back side) of the dentition, the front bristle group 151a acts as a working part that brushes the desired tooth in the dentition, and the rear bristle group 151b acts as a stabilizing part that guides the front bristle group 151a to the desired tooth in response to the user's operation, making it easier to brush in a stable state.

This allows for proper brushing, reducing the risk of adverse effects on the teeth, dentition, and gums.

Furthermore, the toothbrush 102 according to the third embodiment has the handle 160 shifted vertically above the embedded surface 150a and horizontally to the left of the left edge of the embedded surface 150a, so that the embedded surface 150a faces the handle 160, thereby achieving the following advantageous effects. In other words, with conventional toothbrushes in which the head and handle are aligned in a straight line, when brushing the tongue side (back side), the tips of the front teeth interfere with the neck 130 and handle 160 of the toothbrush, so the toothbrush must always be inserted into the mouth at an angle. As a result, the head comes into contact with the tongue side (back side) of the teeth in an inclined position, making it difficult to brush properly.

In contrast, with the toothbrush 102 according to the third embodiment, as shown in FIG. 15, when the handle 160 is positioned on the cheek side 201 of the dentition 200 in the oral cavity, the neck 130 straddles the dentition 200 from above. At this time, the head 150 is positioned so that its embedded surface 150a, as shown in the figure, faces the tongue side 202 of the dentition 200. In this way, the user of the toothbrush 102 can bring the tips of each bristle bundle that makes up the brush head 151 into contact with the tongue side 202 of the dentition 200 in an appropriate position. This makes it possible to more stably achieve appropriate brushing, even on the tongue side, by utilizing a combination of the working part and the stabilizing part.

The toothbrush 102 shown in Figures 14 and 15 is an example of a configuration suitable for brushing the teeth of the lower left and right jaws.

In contrast, the following configuration provides a toothbrush 102 suitable for brushing the dentition of the right lower jaw and left upper jaw. That is, in a toothbrush 102 intended for the dentition of the right lower jaw and left upper jaw, the handle 160 is positioned above the embedded surface 150a in the vertical direction, and is positioned to the right of the right side of the embedded surface 150a in the horizontal direction. The embedded surface 150a is positioned opposite the handle 160. Furthermore, the neck 130 extends diagonally downward and diagonally to the left from the tip 161 of the handle 160, to which the rear end 132 is connected. This allows the tip 131 of the neck 130 to be fixed on the right side surface 150b of the head 150.

(Fourth embodiment)
Fig. 16 is a perspective view showing the configuration of toothbrush 103 according to the fourth embodiment of the present invention, and Fig. 17 is a plan view showing the configuration of toothbrush 103 according to the fourth embodiment. However, components that are the same as or equivalent to those in Figs. 1 to 15 are given the same reference numerals, and detailed descriptions of common components will be omitted. Toothbrush 103 according to the fourth embodiment is preferably used for brushing the tongue side of the dentition.

The toothbrush 103 according to this fourth embodiment has a right brush part 152 embedded on the right side of the triangular planar embedding surface 150a of the head 150, and a left brush part 153 embedded on the left side.

The right brush part 152 has a front group of hair bundles 152a embedded near the front of the head 150, and a rear group of hair bundles 152b embedded near the rear of the head 150 at a predetermined distance rearward from the front group of hair bundles 152a. The left brush part 153 has a front group of hair bundles 153a embedded near the front of the head 150, and a rear group of hair bundles 153b embedded near the rear of the head 150 at a predetermined distance rearward from the front group of hair bundles 153a.

Front hair bundle group 152a and front hair bundle group 153a are each a group of hair bundles embedded toward the front of head 150, and are composed of two hair bundles arranged in the front-to-back direction, two bundles each in the left-to-right direction.

Each of rear hair bundle groups 152b and 153b is a group of hair bundles embedded toward the rear of the head 150, and is composed of four hair bundles, two in the front-to-back direction and two in the left-to-right direction.

Furthermore, as shown in FIG. 17, of the hair bundles arranged in the front-to-back direction that make up the front hair bundle group 152a, the rear hair bundle 152a2 is located to the right of the front hair bundle 152a1. Of the hair bundles arranged in the front-to-back direction that make up the rear hair bundle group 152b, the front hair bundle group 152b3 is located to the right of the rear hair bundle 152a2 of the front hair bundle group 152a, and the rear hair bundle group 152b4 is located to the right of the front hair bundle group 152b3.

Similarly, of the hair bundles arranged in the front-to-back direction that make up the front hair bundle group 153a, the rear hair bundle 153a2 is located to the left of the front hair bundle 153a1. Of the hair bundles arranged in the front-to-back direction that make up the rear hair bundle group 153b, the front hair bundle group 153b3 is located to the left of the rear hair bundle 153a2 of the front hair bundle group 153a, and the rear hair bundle group 153b4 is located to the left of the front hair bundle group 153b3.

As a result, the hair bundles that make up the front hair bundle group 152a and the rear hair bundle group 152b of the right brush part 152 form rows that gradually slope to the right as they move from the front to the rear. Similarly, the hair bundles that make up the front hair bundle group 153a and the rear hair bundle group 153b of the left brush part 153 form rows that gradually slope to the left as they move from the front to the rear.

In other words, the dimensions of the right brush section 152 and the left brush section 153 increase overall from the front end to the rear end of the head section 150 on the embedded surface 150a in the left-right direction, which is perpendicular to the extension direction of the head section 150.

The handle 160 is shifted upward relative to the buried surface 150a of the head 150, and is positioned so that it is on the same line as the center line of the buried surface 150a in the left-right direction, with the buried surface 150a facing the handle 160. The neck 130 connecting the head 150 and handle 160 is positioned so that it is on the same line as the center line of the buried surface 150a in the left-right direction, and extends obliquely from the handle 160 toward the head 150 at a depression angle in the up-down direction.

Furthermore, the front end 131 of the neck 130 is narrower than the rear end 132, i.e., the left-right dimension is smaller, so that when viewed from the top to bottom, the right side 133 and left side 134 are formed as inclined surfaces that narrow obliquely from the handle 160 toward the head 150. Meanwhile, the right side 150c of the head 150, adjacent to the right brush portion 152, is parallel to the right side 133 of the neck 130, and the left side 150b, adjacent to the left brush portion 153, is parallel to the left side 134 of the neck 130.

The toothbrush 103 of the fourth embodiment, having the above-described configuration, achieves the same effects as the toothbrush 101 of the third embodiment through the following action. That is, when brushing the lingual sides of the dentition of the right mandible and left maxilla in the oral cavity, the neck portion 130 and handle portion 160 straddle the dentition from above, and the head portion 150 is positioned so that the embedded surface 150a faces the lingual side (back side) of the dentition 200. This compensates for the tilt of the right brush portion 152 that occurs when the head portion 150 is inserted into the oral cavity with the head portion 150 tilted toward the right side of the toothbrush 103, allowing each bristle bundle that makes up the right brush portion 152 to come into contact in a position nearly parallel to the line connecting the cervical parts of the dentition.

On the other hand, when brushing the teeth of the lower left and right jaws in the oral cavity, the neck portion 130 and handle portion 160 straddle the teeth 200, and the head portion 150 is positioned so that the embedded surface 150a faces the tongue side (back side) of the teeth 200. Furthermore, the tilt of the left brush portion 153 that occurs when the head portion 150 is inserted into the oral cavity at an angle toward the left side of the toothbrush 103 is compensated for, allowing each bristle bundle that makes up the left brush portion 153 to contact the line connecting the cervical portions of the teeth in a position nearly parallel to the line.

In short, with the toothbrush 103 of the fourth embodiment, while the toothbrush 102 of the third embodiment requires two brushes with different shift positions of the handle portion 160 relative to the head portion 150 depending on the brushing position, it is possible to more stably achieve optimal brushing using a combination of the working portion and the stabilizing portion to accommodate all brushing positions in the oral cavity, up, down, left, and right, with just one toothbrush.
Each of the right brush part 152 and the left brush part 153 may be inclined inward with respect to a line perpendicular to the embedded surface 150a, preferably at an angle θ in the range of 5°≦θ≦45°. As a result, when brushing the front side of the dentition, the toothbrush 103 can be used so that the right brush part 152 and the left brush part 153 function as a working part or a stabilizing part, achieving the same effects as those of the first embodiment.

(Other embodiments)
Furthermore, as for toothbrush 104 of another embodiment, Fig. 18(A) shows a right side view of toothbrush 104, Fig. 18(B) shows a bottom view thereof, and Fig. 18(C) shows a cross-sectional view taken along the line E-E of Fig. 18(B). Toothbrush 104 of another embodiment has neck portion 130 and handle portion 160 similar to toothbrush 102 of the third embodiment, but may also have a head portion 150 including brush portion 125 having groups of bristle bundles arranged at equal intervals in the front-to-rear direction and embedded in an orientation perpendicular to embedding surface 150a, similar to conventional toothbrushes.

In another embodiment of the toothbrush 104, when the handle portion 160 is positioned on the front side of the dentition in the oral cavity, the neck portion 130 straddles the dentition from above, and the head portion 150 is positioned so that the embedded surface 150a faces the lingual side (back side) of the dentition 200, allowing each bristle bundle constituting the brush portion 151 to contact the lingual side of the dentition in a position nearly parallel to the line connecting the cervical portions of the dentition.

This provides the following benefits: When brushing the dentition, particularly the tongue side, with conventional toothbrushes, the toothbrush handle would interfere with the tips of the front teeth, so the toothbrush had to be inserted into the mouth at an angle. As a result, the head would be in an inclined position and would come into contact with the tongue side (back side) of the dentition, making it difficult to brush properly.

To address this issue, the toothbrush 104 of this embodiment allows for good brushing without the toothbrush head coming into contact with the tongue side (back side) of the dentition when in an inclined position.

As described above, various modifications can be made to the above-described embodiments in terms of configuration, shape, material, quantity, position, arrangement, etc., without departing from the scope of the technical concept and purpose of the present invention, and such modifications are included in the present invention.

That is, for example, as shown in Figure 4 (B), the toothbrush 100 of the present invention positions the front bristle bundles 121a of the central brush part 121 by contacting them with or near the maximum prominence 220X, which is the most bulging part on the cheek side 221 of the tooth 220. Then, while maintaining the front bristle bundles 121a in this position, the front bristle bundles 123a of the left brush part 123 is placed against the surface 221A below the maximum prominence 220X and between the gum lines, which is prone to soiling. The handle is then operated to move the front bristle bundles 123a back and forth along the direction of the tooth row, thereby brushing the surface 221A.

However, this is not limited to this.
Fig. 19A(A) is a plan view showing the configuration of the main parts of the toothbrush according to the first embodiment of the present invention. Fig. 19B(B) is a view showing the toothbrush according to the first embodiment of the present invention placed so as to cover the buccal surfaces of the upper and lower teeth simultaneously, with the teeth of the left upper and lower jaws lightly in contact with each other in a closed-mouth position. Fig. 19B(C) is a cross-sectional view taken along the line F-F of Fig. 19B(B).

19B(C) is an F _- F cross-sectional view of the toothbrush 100 when the upper and lower teeth on the left side are lightly brought into contact, the buccal surfaces of the maxillary teeth _{210-1 to 260-1} and the mandibular teeth _210-2 to _260-2 are aligned, and the toothbrush 100 is simultaneously placed against the buccal surfaces of the maxillary teeth _210-1 to _260-1 and the mandibular teeth 210-2 to 260-2. By using a toothbrush 100 with an expanded lateral size in this way, when brushing with the toothbrush 100, the front bristle bundles 121a of the central brush part 121 may act as a stabilizing part, the front bristle bundles 122a of the right brush part 122 of the toothbrush 100 may act as a working part for the surface 221A of the maxillary tooth row, and at the same time, the front bristle bundles 123a of the left brush part 123 of the toothbrush 100 may act as a working part for the surface 221A of the mandibular tooth row. In this way, if the user of toothbrush 100 moves the lower jaw slightly to the side and uses toothbrush 100 in a position where the buccal surfaces of the upper and lower teeth are aligned, it is possible to simultaneously brush the areas of the upper and lower teeth where plaque is likely to accumulate, and it is expected that efficient brushing will be possible within the limited time available in daily life.

Fifth Embodiment
Fig. 20 is a perspective view showing the configuration of the main parts of toothbrush 105 according to the fifth embodiment of the present invention. Fig. 21(A) is a front view showing the configuration of the main parts of toothbrush 105 according to the fifth embodiment of the present invention, and Fig. 21(B) is a cross-sectional view taken along the line G-G of Fig. 21(A). Fig. 22(A) is a view showing toothbrush 105 according to the fifth embodiment of the present invention placed against the lingual surface of the left mandibular dentition, as viewed from the occlusal surface, and Fig. 22(B) is a cross-sectional view taken along the line H-H of Fig. 22(A).

As shown in the figures, the toothbrush 105 according to the fifth embodiment of the present invention comprises a head 110, a brush section 120 in which bristle bundles that form the brush body for brushing teeth are embedded in the main surface of the head 110, and a neck section 130 that connects the head 110 to a handle section (not shown) that allows the user to grasp and operate the toothbrush. It is preferable that the head 110, neck section 130, and handle section are each made of synthetic resin. The head 110, neck section 130, and handle section may each be combined as separate pieces, or all or part of them may be molded as a single piece.

In the following description, as shown in Figure 20, the side of the head 110 that is connected to the neck 130 is referred to as the rear side, the tip side of the head 110 that is not connected to anything is referred to as the front side, and the direction connecting the front and rear sides of the head 110 is defined as the extension direction of the head and is referred to as the front-to-back direction. Furthermore, the side of the head 110 that is closer to the right hand when viewed from the front is referred to as the right side, the side of the head 110 that is closer to the left hand when viewed from the front is referred to as the left side, and the direction perpendicular to the extension direction of the head 110 is referred to as the left-to-right direction. Furthermore, the side of the head 110 on which the brush part 120 is embedded is referred to as the upper side, the side on which the brush part 120 is not embedded is referred to as the lower side, and the direction connecting the upper and lower sides, which is perpendicular to both the front-to-back direction and the left-to-right direction, is referred to as the up-down direction. These directions are shown in each figure using Cartesian coordinates.

(head)
The head 110 is a part located at the tip in the front-to-rear direction of the toothbrush 105. When viewed from the front, the head 110 is integrally formed with a central portion 111, a right portion 112 located to the right of the central portion 111, and a left portion 113 located to the left of the central portion 111. A front surface 110fr is formed on the front side of the head 110.

In the head 110, the central portion 111 has a central buried surface 111a that is parallel to the front-to-back and left-to-right plane and has a roughly rectangular outer shape with the front-to-back direction as the longitudinal direction in a plan view. The right side portion 112 has a right buried surface 112a that is an inclined surface extending from the right long side of the central portion 111 toward the central buried surface 111a and has a roughly rectangular outer shape with the front-to-back direction as the longitudinal direction in a plan view. The left side portion 113 has a left buried surface 113a that is an inclined surface extending from the left long side of the central portion 111 toward the central buried surface 111a and has a roughly rectangular outer shape with the front-to-back direction as the longitudinal direction in a plan view. The right buried surface 112a and the left buried surface 113a are inclined at angles that are symmetrical to the central buried surface 111a in a front-to-back view.

(Brush part)
The brush part 120 has a central brush part 121 embedded in the central embedded surface 111a of the central part 111 of the head 110, a right brush part 122 embedded in the right embedded surface 112a of the right part 112 of the head 110, and a left brush part 123 embedded in the left embedded surface 113a of the left part 113 of the head 110.

In the brush section 120, the central brush section 121 is embedded perpendicular to the central embedded surface 111a. The bristle bundles of the right brush section 122 are embedded perpendicular to the right embedded surface 112a. The left brush section 123 is embedded perpendicular to the left embedded surface 113a.

Furthermore, as shown in FIG. 21(B), it is preferable that the dimension t1 from the tips of the front hair bundle group 123a and the rear hair bundle group 123b of the left brush part 123 to the central buried surface 111a is larger than the dimension t2 from the tips of the front hair bundle group 121a and the rear hair bundle group 121b of the central brush part 121 to the central buried surface 111a. Similarly, it is preferable that the dimension t1 from the tips of the front hair bundle group 122a and the rear hair bundle group 122b of the right brush part 122 to the central buried surface 111a is larger than the dimension t2 from the tips of the front hair bundle group 121a and the rear hair bundle group 121b of the central brush part 121 to the central buried surface 111a.

As a result, in the head 110, the central brush part 121 stands upright in the vertical direction, the right brush part 122 and the left brush part 123 are each inclined toward the central brush part 121, and the tips forming their brushing surfaces are positioned at the same height as the tip of the central brush part 121. As shown in Figure 21 (A), the inclination angle θ of each of the right brush part 122 and the left brush part 123 toward the central brush part 121 is preferably around 45°.

Each of the central brush part 121, right brush part 122, and left brush part 123 of the brush part 120 has a pair of hair bundle groups arranged with the front-to-back direction as the longitudinal direction. Specifically, the central brush part 121 has a front hair bundle group 121a embedded toward the front of the head 110 and a rear hair bundle group 121b embedded a predetermined distance rearward from the front hair bundle group 121a. The right brush part 122 has a front hair bundle group 122a embedded toward the front of the head 110 and a rear hair bundle group 122b embedded a predetermined distance rearward from the front hair bundle group 122a. The left brush part 123 has a front hair bundle group 123a embedded toward the front of the head 110 and a rear hair bundle group 123b embedded a predetermined distance rearward from the front hair bundle group 123a.

Each of the front hair bundle group 121a and the rear hair bundle group 121b is composed of two pairs (four bundles) of hair bundles arranged in the front-to-back direction, as shown in each figure. Each of the front hair bundle group 122a and the rear hair bundle group 122b, and the front hair bundle group 123a and the rear hair bundle group 123b is composed of two pairs (four bundles) of hair bundles arranged in the front-to-back direction and the left-to-right direction, two bundles each.

As shown in FIG. 20 in particular, front hair bundle group 121a, front hair bundle group 122a, and front hair bundle group 123a are each positioned at the same position closer to the front in the front-to-back direction, thereby constituting front brush group 120a, which is arranged with the left-to-right direction as its longitudinal direction. Rear hair bundle group 121b, rear hair bundle group 122b, and rear hair bundle group 123b are each positioned at the same position closer to the rear in the front-to-back direction, thereby constituting rear brush group 120b, which is arranged with the left-to-right direction as its longitudinal direction.

The specified distance between the front brush group 120a and the rear brush group 120b is preferably large enough to accommodate at least two teeth when brushing the lingual tooth surfaces. The specified distance between the front brush group 120a and the rear brush group 120b may also be large enough to prevent both the brushing surfaces of the front brush group 120a and the rear brush group 120b from coming into contact with a single tooth, and the specified distance between the front brush group 120a and the rear brush group 120b may also be close to each other.

The toothbrush 105 according to the fifth embodiment of the present invention, which has the above-described configuration, is characterized in that the brush section 120 is composed of a combination of a front brush group 120a and a rear brush group 120b, the front brush group 120a is configured to include combinations of a front bristle group 121a and a front bristle group 122a, and a front bristle group 121a and a front bristle group 123a, and the rear brush group 120b is configured to include combinations of a rear bristle group 121b and a rear bristle group 122b, and a rear bristle group 121b and a rear bristle group 123b, each combination corresponding to a combination of a working section and a stabilizing section, which will be described later.

The following describes the effects of the toothbrush 105 based on a preferred example of use of the toothbrush 105 according to the first embodiment of the present invention, with reference to Figure 21 as well.

Figure 22(A) shows a schematic diagram of the state when brushing the lingual side of the left mandibular dentition 200. Figure 22(A) shows a view from the occlusal surface of a toothbrush 105 according to a fifth embodiment of the present invention placed against the lingual side of the left mandibular dentition. The toothbrush 105 is used in the oral cavity so that the brushing surface formed by the front bristle group 123a and the rear bristle group 123b of the left brush section 123 of the brush head 120 faces the lingual side (back side) of the dentition 200, which includes teeth 210, 220, 230, 240, 250, and 260. However, in this example, the toothbrush 105 is held in the user's right hand, and the brushing surface of the brush head 120 faces the lingual side (back side) of the dentition 200.

As shown in Figures 22(A) and (B), first, the right brush part 122 is brought into contact with the occlusal surfaces 203 of teeth 210 and 220, and the central brush part 121 is brought into contact with the ridge 205 at the boundary between the occlusal surfaces 203 and the lingual surfaces 204 of teeth 210 and 220, and while maintaining this position, the left brush part 123 is placed against the lingual surfaces 204 of teeth 210 and 220, and the handle is moved back and forth to brush the surfaces of the lingual surfaces 204 of teeth 210 and 220. At this time, moving the handle back and forth while it is in contact with the tips of teeth 250 and 260 prevents pitching of the toothbrush 105, ensuring stable brushing.

In this way, in the toothbrush 105 according to the fifth embodiment, when brushing the lingual side (back side) of the dentition, the left brush part 123 of the brush unit 120 acts as the working part that brushes the lingual surfaces 204 of the teeth 210 and 220, and the central brush part 121 and right brush part 122 of the brush unit 120 act as stabilizing parts.

In this way, the toothbrush 105 according to the fifth embodiment is configured so that when the brush unit 120 brushes the tongue side (back side) of the teeth, the left brush unit 123 acts as the working unit that brushes the teeth in the dentition, and the central brush unit 121 and right brush unit 122 of the brush unit 120 act as stabilizing units that guide the working unit to the correct posture and target position in response to the user's operation, making it easier to brush in a stable state.

The present invention as described above has the effect of enabling proper brushing without adversely affecting the teeth, dentition, or gums, and is useful when applied to toothbrushes.

100, 100A to 100D, 101, 101A to 101D, 102, 103, 104, 105 Toothbrush 110, 150 Head 110fr, 150fr Front surface 111 Central portion 111a Central buried surface 112 Right side portion 112a Right buried surface 113 Left side portion 113a Left buried surface 120, 125, 151 Brush portion 120a Front brush group 120b Rear brush group 121 Central brush portion 121a, 122a, 123a, 151a, 152a, 153a Front bristle bundle group 121b, 122b, 123b, 151b, 152b, 153b Rear bristle bundle group 122, 152 Right brush portion 123, 153 Left brush portion 124 152b3, 152b4, 153b3, 153b4 Group of tufts 130 Neck 131, 161 Tip 132 Rear end 133, 150b Right side 134, 150c Left side 141, 142 Stopper 141a Front stopper 141b Rear stopper 150a Buried surface 152a1, 152a2, 152b1, 152b2, 153a1, 153a2, 153b1, 153b2 Tuft 160 Handle 200 Tooth row 201, 221 Buccal side 202 Lingual side 203 Occlusal surface 204 Lingual surface 205 Ridge 210, 220, 230, 240, 250, 260 Teeth ₂₁₀₁ , ₂₂₀₁ , 230 ₁ , ₂₄₀₁ , ₂₅₀₁ , ₂₆₀₁ Upper jaw teeth ₂₁₀₂ , ₂₂₀₂ , ₂₃₀₂ , ₂₄₀₂ , ₂₅₀₂ , ₂₆₀₂ Lower jaw teeth 220X Maximum contoured portion 221A, 310 Surface 221B Tip side from maximum contoured portion 300 Gums 301a, 301b Direction and magnitude of repetitive toothbrush movement

Claims (7)

The toothbrush is provided with a working part that is made up of a tuft or a group of tufts protruding from the surface of the head and that brushes the teeth in the dentition , and a stabilizing part that is made up of a tuft or a group of tufts or a member other than a tuft or a group of tufts and that guides the working part to a target position in an appropriate position relative to the front side of the teeth in response to the user's operation, making it easier to brush in a stable state .
The working section and the stabilizing section are
The longitudinal direction of each of the head portions is the direction of arrangement along the extension direction of the head portion, and The longitudinal direction of each of the head portions is the direction of arrangement along a direction intersecting the extension direction of the head portion,
and
The working portion and the stabilizing portion, which are arranged along the extension direction of the head portion, are spaced apart from each other,
The working unit and the stabilizing unit are arranged along a direction intersecting the extension direction of the head, and one of the working unit and the stabilizing unit is inclined relative to the other when viewed in the extension direction of the head,
The stabilizing portion arranged along a direction intersecting the extension direction of the head portion is divided into two stabilizing portions,
The two stabilizing portions include one stabilizing portion for maintaining a constant distance between the toothbrush and the tooth surface, and the other stabilizing portion for preventing rolling around the axis in the extension direction.
toothbrush. The pair of the working unit and the stabilizing unit is
those arranged along the extension direction of the head portion, and those arranged along a direction intersecting the extension direction of the head portion,
Includes both
The brushing surface formed by the working portion arranged along the extension direction of the head and the brushing surface formed by the other stabilizing portion arranged along the extension direction of the head are at the same height,
The brushing surface formed by the working portion arranged along the direction intersecting the extension direction of the head portion is located at a higher position than the brushing surface formed by one of the stabilizing portions arranged along the direction intersecting the extension direction of the head portion, when viewed in the extension direction of the head portion.
The toothbrush of claim 1. The working units are arranged in a direction intersecting the extension direction of the head,
When viewed in the extension direction of the head, the one stabilizing portion is formed symmetrically with respect to the one stabilizing portion arranged along a direction intersecting the extension direction of the head.
The toothbrush of claim 2. The pair of the working unit and the stabilizing unit is
Only those arranged along the extension direction of the head,
The brushing surface formed by the working portion arranged along the extension direction of the head and the brushing surface formed by the other stabilizing portion arranged along the extension direction of the head are at the same height,
The brushing surface formed by the working portion arranged along the direction intersecting the extension direction of the head portion has a dimension along the direction intersecting the extension direction of the head portion larger than the brushing surface formed by one of the stabilizing portions arranged along the direction intersecting the extension direction of the head portion when viewed in a direction parallel to the surface of the head portion.
The toothbrush of claim 1. Each of the cleaning surfaces of the working section and the stabilizing section is
In a plan view parallel to the surface of the head, the dimension along a direction intersecting the extension direction of the head increases from the tip to the rear end of the head.
5. The toothbrush of claim 4. The hair shaving device is provided with a working part that is protruding from the surface of the head and is made up of a hair bundle or a group of hair bundles, and a stabilizing part that is made up of a hair bundle or a group of hair bundles or a member other than a hair bundle or a group of hair bundles,
The working section and the stabilizing section are
The longitudinal direction of each of the head portions is the direction of arrangement along the extension direction of the head portion; and
The longitudinal direction is an arrangement direction along a direction intersecting the extension direction of the head portion,
and
The working portion and the stabilizing portion, which are arranged along the extension direction of the head portion, are spaced apart from each other,
A handle portion for operating the head portion;
a neck portion connecting the head portion and the handle portion,
The neck portion is connected to the handle portion at a position shifted from the head portion along each of two directions perpendicular to the extension direction of the head portion when viewed in the extension direction of the head portion, and at a position where the surface of the head portion faces the handle portion.
toothbrush . Each of the cleaning surfaces of the working section and the stabilizing section is
In a plan view parallel to the surface of the head, the dimension along a direction intersecting the extension direction of the head increases from the tip to the rear end of the head.
7. The toothbrush of claim 6 .