Toothbrushes and how toothbrushes are manufactured.

Abstract

DEPCT68 A toothbrush that can achieve adequate cleaning properties for each position in the body. The oral cavity and high tightness with the supporting tooth rows have properly fitted gripping and connecting parts. Connected to the handle, the connector is the brush part, which is the first and second forming part. Unlike the first type of molding, it has supports that hold the brush section in a circular direction around the axis. Extending in a converging direction, the brush section has a base, bristles extending from the base, and a... The connector is attached to the support provided at the base;

Description

Toothbrush and method for manufacturing toothbrush

[0001] This application claims priority to Japanese Patent Application No. 2022-106249 filed in Japan on June 30, 2022, Japanese Patent Application No. 2022-106010 filed in Japan on June 30, 2022, Japanese Patent Application No. 2022-204420 filed in Japan on December 21, 2022, and Japanese Patent Application No. 2022-209653 filed in Japan on December 27, 2022, the contents of which are incorporated herein by reference.

[0002] Patent Literature 1 discloses a mouthpiece-type, electrically driven toothbrush that cleans the entire dentition at once. The electric toothbrush disclosed in Patent Literature 1 includes a mouthpiece that is arranged on a support so that cleaning elements, which are brush parts, simultaneously engage with substantially all of the teeth on at least one of the user's upper and lower jaws, and an electric drive unit that is detachably fixed to the mouthpiece and has at least one vibration element for performing a vibration motion.

[0003] Special table 2019-520919 publication

[0004] In the toothbrush disclosed in Patent Document 1, due to the positional relationship of the brush part relative to the support, the mold is moved in an undercut state to forcibly release the molded product (forced removal). Therefore, the brush part must be as soft as possible and have a simple arrangement to facilitate removal from the mold. As a result, problems arise, such as a decrease in bristle stiffness and limitations on the designable step profile, resulting in insufficient cleaning power. Furthermore, the brush part cannot be optimized for each area of ​​the oral cavity, which prevents full utilization of the benefits of the mouthpiece design, which allows the entire oral cavity to be brushed at once. Furthermore, the support is made of the same soft resin material as the brush part. Therefore, biting the support during use tends to cause the support to spread excessively. This results in a problem of poor fit to the dentition.

[0005] Furthermore, the toothbrush disclosed in Patent Document 1 is a mouthpiece-type toothbrush in which the brush head and support are integrally molded from a soft resin. Therefore, compared to long toothbrushes with standard bristles, the brush head has a larger diameter at the tip, making it difficult to reach interdental spaces and periodontal pockets; the bristles are less dense than standard bristles, reducing the contact area with the teeth and gums; and the bristles tend to bend in a consistent direction, making it difficult to achieve a clean feeling. Therefore, users who expect the texture and cleaning effect of a standard toothbrush tend to rate the cleaning feeling as low. Furthermore, due to the integral molding, the positional relationship of the brush head in the mouthpiece imposes constraints on the brush arrangement design, making it difficult to achieve an arrangement that suits the characteristics of each area. As a result, it is not possible to clean multiple areas simultaneously in a manner appropriate for each area, resulting in reduced cleaning performance, such as plaque removal rate.

[0006] Furthermore, in the toothbrush disclosed in Patent Document 1, the support has a U-shaped portion supporting the brush section closest to the grip, a U-shaped portion supporting the brush section farther from the grip, and a connecting portion connecting these two portions. The connecting portion connects the two U-shaped portions along the entire circumferential direction (i.e., the length direction), so the distance between the two U-shaped portions remains constant and they vibrate together. In other words, in the toothbrush disclosed in Patent Document 1, the brush section located on the outside of the teeth and the brush section located on the inside of the teeth move together, which reduces the fit to the outer and inner dentition, which have different circumferential lengths and shapes, and reduces the cleaning experience. Furthermore, the toothbrush cannot accommodate the different dentition dimensions between men and women, or between adults and children, which differ in the depth dimension connecting the cheek side and tongue side, resulting in a poor fit to the dentition. These problems are not limited to toothbrushes with electrically driven mouthpieces, but are common to toothbrushes that clean the entire dentition at once.

[0007] The present invention was made in consideration of the above points, and its first object is to provide a toothbrush and a method for manufacturing a toothbrush that can achieve sufficient cleaning performance for each area in the oral cavity and a support that closely fits the dentition. A second object of the present invention is to provide a toothbrush and a method for manufacturing a toothbrush that improves the cleaning feel and cleaning performance. A third object of the present invention is to provide a toothbrush that closely fits the dentition and provides a closely fitting cleaning feel. A fourth object of the present invention is to provide a toothbrush that improves the fit to the dentition.

[0008] The present invention has the following aspects. [1] A toothbrush having a grip portion and a connecting body connected to the grip portion, wherein the connecting body has a brush portion that is a first molded body and a support that is a second molded body different from the first molded body and supports the brush portion in a circumferential direction centered on an axis extending in the interdigital coupling direction, wherein the brush portion has a base portion, filaments extending from the base portion, and a connecting portion that is provided on the base portion and connects to the support. [2] The toothbrush described in [1], wherein a plurality of the brush portions are arranged in at least one of the circumferential direction, the interdigital coupling direction, and a depth direction perpendicular to the circumferential direction and the interdigital coupling direction. [3] The toothbrush described in [2], wherein the base portion of at least one of the brush portions is curved along the circumferential direction. [4] The toothbrush according to [2] or [3], wherein at least one of the brush parts is formed of a soft resin having a Shore A hardness of 40 or more and a Shore D hardness of 70 or less, and the thickness of the base part in the depth direction is 1 mm or more and 5 mm or less. [5] The toothbrush according to any one of [2] to [4], wherein the brush parts are arranged separately on the outside and inside in the depth direction, and the outside brush part and the inside brush part each have a central region including the center of the support in the circumferential direction and an end region located at an end of the support in the circumferential direction, and the distance between the filament with the shortest bristle length in the outside brush part and the filament with the shortest bristle length in the inside brush part in the end region is greater than the distance between the filament with the shortest bristle length in the outside brush part and the filament with the shortest bristle length in the inside brush part in the central region. [6] The toothbrush according to any one of [1] to [5], wherein the filaments extend from the brush surface of the base portion, and the linear distance connecting both ends of the circumferential direction on the brush surface is 5 mm or more. [7] The toothbrush according to any one of [1] to [6], wherein the support is formed of a resin that is harder than the brush portion. [8] The toothbrush according to any one of [1] to [7], wherein the brush portion has a portion where the arrangement pitch of the base portions and the arrangement pitch of the bristle tips of the plurality of filaments arranged in the circumferential direction are different.[9] The toothbrush according to any one of [1] to [8], which includes an elastic member that has a higher hardness than the brush section and the support, and that elastically deforms and curves the support along the circumferential direction.

[10] The toothbrush according to any one of [1] to [9], wherein the handle has an electric drive unit including a vibration element, and the connecting body vibrates when driven by the vibration element.

[11] A toothbrush manufacturing method for a toothbrush having a handle and a connecting body connected to the handle, wherein the connecting body is a brush section that is a first molded body, and a support that is a second molded body different from the first molded body and supports the brush section in the circumferential direction centered on an axis extending in the interdigital coupling direction, the toothbrush manufacturing method including: preparing the brush section having a base portion, a filament extending from the base portion, and a connecting portion that is provided on the base portion and connects to the support, preparing the support, and connecting the brush section to the support at the connecting portion.

[12] A toothbrush having a handle and a connector connected to the handle, the connector having a brush section with a base section to which a bundle of bristles is attached, and a support body molded from a material different from the base section, covering at least a portion of the base section, and supporting the brush section in a circumferential direction about an axis extending in the intermeshing direction.

[13] The toothbrush described in

[12] , wherein a plurality of the brush sections are arranged in at least one direction of the circumferential direction and a depth direction perpendicular to the circumferential direction and the intermeshing direction.

[14] The toothbrush described in

[13] , wherein the brush parts are respectively arranged at a distance on the outside and inside in the depth direction, and the outside brush part and the inside brush part each have a central region including the center of the circumferential direction of the support body and an end region located at the end of the circumferential direction of the support body, and the distance in the end region between the bristle bundle with the shortest bristle length in the outside brush part and the bristle bundle with the shortest bristle length in the inside brush part is greater than the distance in the central region between the bristle bundle with the shortest bristle length in the outside brush part and the bristle bundle with the shortest bristle length in the inside brush part.

[15] The toothbrush according to any one of

[12] to

[14] , wherein a plurality of bristle bundles are arranged in the circumferential direction in a plurality of rows in the intermeshing direction, and the bristle bundles in at least one of the bristle bundle rows located at an end in the intermeshing direction have bristle tips that are inclined toward the end with respect to the roots.

[16] The toothbrush according to any one of

[12] to

[15] , wherein the brush head has a portion where the arrangement pitch of the roots and the arrangement pitch of the bristle tips of the plurality of bristle bundles arranged in the circumferential direction are different.

[17] The toothbrush according to any one of

[12] to

[17] , wherein the length in the intermeshing direction of the base portion of the outer brush portion located in the central region is WA1, the length in the intermeshing direction of the base portion of the outer brush portion located in the end region is WA3, the length in the intermeshing direction of the base portion of the inner brush portion located in the central region is WB1, and the length in the intermeshing direction of the base portion of the inner brush portion located in the end region is WB3, so that the relationships WA1 > WA3 and WB1 > WB3 are satisfied.

[18] The toothbrush according to any one of

[12] to

[17] , wherein the handle has an electric drive unit including a vibration element, and the connecting body vibrates when driven by the vibration element.

[19] A toothbrush manufacturing method for a toothbrush having a handle portion and a connecting body connected to the handle portion, the connecting body having a brush portion with a tuft of bristles provided on a base portion, and a support body molded from a material different from the base portion, covering at least a portion of the base portion, and supporting the brush portion in a circumferential direction centered on an axis extending in the meshing direction, the method comprising: preparing the brush portion; preparing the support body; and joining the brush portion to the support body.

[20] A toothbrush having a gripping portion and a connecting body connected to the gripping portion on one side in a depth direction perpendicular to an interlocking direction, the connecting body having a first brush body located on one side of the gripping portion in the depth direction, and a second brush body located between the gripping portion and the first brush body in the depth direction and spaced apart from the first brush body, the first brush body being U-shaped along a circumferential direction centered on an axis extending in the interlocking direction, and having a first support that opens to one side in the depth direction, and a first brush portion extending from the first support to the other side in the depth direction, the second brush body being U-shaped along the circumferential direction, and having a second support that opens to one side in the depth direction, and a second brush portion extending from the second support to one side in the depth direction, the first support and the second support being independently movable relative to each other in both the depth direction and the circumferential direction.

[21] The toothbrush according to

[20] , wherein the first support and the second support facing each other in the depth direction have different shape characteristics, including the depth dimension, or different material characteristics, including hardness.

[22] The toothbrush according to

[21] , wherein the depth dimension of the first support is 1.5 mm or more and 7 mm or less, the depth dimension of the second support is 1.5 mm or more and 6 mm or less, and the depth dimension of the circumferential end of the first support is greater than the depth dimension of the circumferential end of the second support.

[23] The toothbrush according to any one of

[20] to

[22] , wherein the proportion of the length of the region separated from the second support in the depth direction to the circumferential length of the first support is 20% or more and 70% or less.

[24] A toothbrush described in any one of

[20] to

[23] , which is provided with at least one of a first hard plate formed from a resin harder than the first support and arranged along the circumferential direction on the first support, and a second hard plate formed from a resin harder than the second support and arranged along the circumferential direction on the second support.

[25] The toothbrush according to

[24] , wherein the first hard plate applies tension to the first support toward the other side in the depth direction when a load is applied to the first support toward one side in the depth direction, and the second hard plate applies tension to the second support toward one side in the depth direction when a load is applied to the second support toward the other side in the depth direction.

[26] The toothbrush according to any one of

[20] to

[25] , wherein the toothbrush has a connecting portion connecting the first support and the second support in the depth direction, and the connecting portion is an elastic body that elastically deforms in the depth direction in response to deformation in the interlocking direction.

[27] The toothbrush according to any one of

[20] to

[26] , wherein the toothbrush has a connecting portion connecting the first support and the second support in the depth direction, and when the connecting portion is compressed in the interlocking direction, at least a portion of the first support and the second support moves toward a center of the connecting portion in the depth direction.

[28] A toothbrush having a gripping portion and a connecting body connected to the gripping portion on one side in a depth direction perpendicular to an interlocking direction, the connecting body having a first brush body located on one side of the gripping portion in the depth direction, and a second brush body located between the gripping portion and the first brush body in the depth direction and spaced apart from the first brush body, the first brush body having a first support formed in a U-shape that opens to one side in the depth direction along a circumferential direction centered on an axis extending in the interlocking direction, and a first brush portion extending from the first support to the other side in the depth direction, the second brush body having a second support formed in a U-shape that opens to one side in the depth direction along the circumferential direction, and a second brush portion extending from the second support to one side in the depth direction, and having an adjustment portion that can adjust the distance in the depth direction between the first support and the second support in an unloaded state.

[29] The toothbrush according to

[28] , wherein the first support and the second support have regions spaced apart in the depth direction.

[30] The toothbrush according to

[28] or

[29] , wherein the adjustment unit is provided at least at a central position in the circumferential direction of the first support and the second support.

[31] The toothbrush according to any one of

[28] to

[30] , which includes at least one of a first hard plate made of a resin harder than the first support and provided on the first support along the circumferential direction, and a second hard plate made of a resin harder than the second support and provided on the second support along the circumferential direction.

[32] The toothbrush according to any one of

[28] to

[31] , which includes an adjustment unit that can continuously change the distance between the first support and the second support in accordance with the load on the adjustment unit in the depth direction.

[33] The toothbrush according to any one of

[28] to

[32] , which includes a third brush part on at least one side of the meshing direction.

[0009] The present invention can achieve sufficient cleaning performance for each area in the oral cavity and a high cleaning sensation due to the support body's excellent fit to the dentition. The present invention also provides a toothbrush and a toothbrush manufacturing method that improve the cleaning sensation and cleaning performance. It also provides a toothbrush that provides an excellent fit to the dentition and a high cleaning sensation. It also provides a toothbrush that improves the fit to the dentition.

[0010] 1 is a diagram showing an embodiment of the present invention, and is a front view of a toothbrush 1 of a first embodiment. FIG. 1 is an external perspective view of a brush portion 30 of a first embodiment of a mouthpiece portion 20. FIG. 1 is a cross-sectional view taken along CC in FIG. 1. FIG. 2 is a view of an inner upper brush portion 31A as viewed from above. FIG. 3 is a side view of an inner upper brush portion 31B as viewed from the right side. FIG. 4 is a view of an outer upper brush portion 32A as viewed from above. FIG. 5 is a side view of an outer upper brush portion 32B and an outer upper brush portion 32C as viewed from the inside. FIG. 6 is an external perspective view of a support body 50 of a first embodiment of a mouthpiece portion 20. FIG. 7 is a perspective cross-sectional view of a support body 50 of a first embodiment of a mouthpiece portion 20. FIG. 8 is a side view showing a modified example of a connecting portion. FIG. 9 is a cross-sectional view showing a modified example of a connecting portion. FIG. 10 is a plan view schematically showing a mouthpiece portion 20 of a second embodiment. FIG. 11 is a plan view schematically showing a mouthpiece portion 20 of a third embodiment. FIG. 12 is a side view schematically showing a mouthpiece portion 20 before elastic members 81, 82 are attached. FIG. 13 is a plan view schematically showing a mouthpiece portion 20 of a fourth embodiment. 17A and 17B are side views schematically showing the mouthpiece portion 20 before the elastic members 81 and 82 are attached. FIG. 26 is a front view of the toothbrush 101 of the second embodiment, showing an embodiment of the present invention. FIG. 27 is a view of the brush portion 130 of the mouthpiece portion 120 as seen from above. A cross-sectional view taken along CC in FIG. 17A. FIG. 28 is a view of the inner upper brush portion 131A as seen from above. FIG. 29 is a view of the outer upper brush portion 132A as seen from above. FIG. 29 is a perspective view of the outer surface of the support 150 of the fifth embodiment of the mouthpiece portion 120. A cross-sectional perspective view ... perspective view showing a modified example of the mouthpiece portion 120. FIG. 26A is a front view of the toothbrush 201 of the third embodiment, showing an embodiment of the present invention. FIG. 29 is a cross-sectional view taken along CC in FIG. 25A. 26 is a front view of the first brush body 230, the second brush body 260, and the connecting portion 280, excluding the connecting portions between the first brush portion 241, the second brush portion 271, and the grip portion 210. FIG. 26 is a cross-sectional view taken along the line D-D in FIG. 26. FIG. 26 is a front view of the mouthpiece portion 220 according to a seventh embodiment of the present invention. FIG. 26 is a front view of the mouthpiece portion 220 according to an eighth embodiment of the present invention. FIG. 26 is a front view of the mouthpiece portion 220 according to a ninth embodiment of the present invention.FIG. 26 is a front view of a mouthpiece portion 220 according to a tenth embodiment of the present invention. FIG. 27 is a front view of a mouthpiece portion 220 according to an eleventh embodiment of the present invention. FIG. 28 is a cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a twelfth embodiment of the present invention. FIG. 29 is a schematic cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a thirteenth embodiment of the present invention. FIG. 29 is a schematic cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a thirteenth embodiment of the present invention. FIG. 29 is a schematic cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a fourteenth embodiment of the present invention. FIG. 29 is a schematic cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a fourteenth embodiment of the present invention. FIG. 29 is a schematic cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a fourteenth embodiment of the present invention. FIG. 29 is a schematic cross-sectional view taken along B-B in FIG. 26, which is a partial cross-sectional view of a mouthpiece portion 220 according to a fourteenth embodiment of the present invention. 46. ​​A side view of the first hard plate 236 and the second hard plate 266 constituting the mouthpiece portion 220 according to a fifteenth embodiment of the present invention, as viewed from the left side. This is a diagram showing an embodiment of the present invention, and is a front view of a toothbrush 301 according to a fourth embodiment. This is an external perspective view of a mouthpiece portion 320 according to a sixteenth embodiment. This is a cross-sectional view taken along the line B-B in FIG. 46. This is a cross-sectional view taken along the line C-C in FIG. 45. This is a front view of the first brush body 330, the second brush body 360, and the connecting portion 380, excluding the connecting portions of the first brush portion 341, the second brush portion 371, and the grip portion 310. This is a front view of a state in which the fitting protrusion 351 and the fitting cylindrical portion 356 are spaced apart in the depth direction. This is a front view of a state in which the fitting protrusion 351 is inserted into the fitting cylindrical portion 356. This is a front view of a mouthpiece portion 320 according to a seventeenth embodiment. This is a front view of a mouthpiece portion 320 according to an eighteenth embodiment, in which the fitting protrusion 351 and the fitting cylindrical portion 356 are spaced apart in the depth direction. 19A and 19B are partial front views of an adjustment section 350 according to a nineteenth embodiment of the mouthpiece section 320. FIG. 20B are partial front views of an adjustment section 350 according to a twentieth embodiment of the mouthpiece section 320.

[0011] A toothbrush and a toothbrush manufacturing method according to a first embodiment of the present invention will be described below with reference to Figures 1 to 16. Note that the following embodiment shows one aspect of the present invention, does not limit the present invention, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of each structure are different from the actual structure to make each component easier to understand.

[0012] In the coordinate systems shown in the figures, the Z-axis direction is parallel to the direction in which the axis J extends in the occlusion direction and is the up-down direction. The θ-direction is the circumferential direction centered on the axis J and is the direction along the tooth row. In this embodiment, the circumferential direction includes not only the direction along the arc centered on the axis J but also the direction along the tangent to the arc. The Y-axis direction is perpendicular to the θ-direction and the Z-axis direction and is the depth direction within the oral cavity. In the following description, the direction parallel to the Z-axis direction is referred to as the "occlusion direction." Furthermore, the maxillary side, which is the positive side of the Z-axis direction, is referred to as the "upper side," and the mandibular side, which is the negative side of the Z-axis direction, is referred to as the "lower side." The positive side of the θ-direction is referred to as the "left side," and the negative side of the θ-direction is referred to as the "right side." The tongue side, which is the positive side of the depth direction, is referred to as the "inner side," and the cheek side, which is the negative side of the depth direction, is referred to as the "outer side."

[0013] [First Embodiment of Toothbrush] Fig. 1 is a front view of a toothbrush 1 according to a first embodiment. The toothbrush 1 is a mouthpiece-type toothbrush, and has a grip portion 10 and a connector 20. Hereinafter, the connector 20 will be referred to as the mouthpiece portion 20. Vibrations are imparted to the connector 20 via the grip portion 10. A shaft 14 protrudes from the grip portion 10 and is connected to the mouthpiece portion 20. Note that the shaft 14 protruding from the mouthpiece portion 20 may also be connected to the grip portion 10. Vibrations are imparted to the connector 20 from the grip portion 10 via the shaft 14.

[0014] The present invention is applicable to any of a configuration in which a brushing action is manually applied from the grip portion 10 to the mouthpiece portion 20 in up-down, left-right, front-rear, or a combination thereof, a configuration in which vibration is manually applied, and a configuration in which vibration is electrically applied from the grip portion 10 to the mouthpiece portion 20. In this embodiment, an electric drive unit is provided in the grip portion 10, and vibrations generated by driving the electric drive unit are applied to the mouthpiece portion 20.

[0015] The electric drive unit includes a power supply 11, a vibration element 12, and a control unit 13. The control unit 13 drives the vibration element 12 using power from the power supply 11. The power supply 11 is configured, for example, with a rechargeable battery or a battery. The vibration element 12 is configured, for example, with a piezoelectric element, an electromagnetic acoustic transducer, an unbalanced motor, or the like. The vibration generated by the vibration element 12 is a vibration that rotates around an axis extending in the depth direction, and repeatedly reverses its rotational direction at a predetermined rotation angle. The shaft 14 connected to the electric drive unit in the grip 10 vibrates by repeatedly reversing its rotational direction. As the shaft 14 vibrates due to the drive of the vibration element 12, the mouthpiece 20 vibrates by repeatedly reversing its rotational direction.

[0016] [First embodiment of mouthpiece portion 20] The mouthpiece portion 20 has a brush portion 30 and a support body 50. Fig. 2 is an external perspective view of the brush portion 30 in the first embodiment of the mouthpiece portion 20. Fig. 2 is a perspective view of the brush portion 30 as seen from the inside in the depth direction.

[0017] As shown in Figure 2, the brush units 30 are arranged at separate locations on the outside and inside in the depth direction. The brush unit 30 has an inner brush unit 31 and an outer brush unit 32. The inner brush unit 31 is located on the inside in the depth direction. The inner brush unit 31 has inner upper brush units 31A, 31B, and 31C and inner lower brush units 31D, 31E, and 31F. The inner upper brush units 31A, 31B, and 31C are located on the upper side and are arranged circumferentially opposite the tongue-side tooth surfaces of the maxillary tooth row. The inner upper brush units 31A, 31B, and 31C are arranged in a U-shape, with the inner upper brush unit 31A in the center and the inner upper brush units 31B and 31C arranged on both sides of the circumferential direction at a distance.

[0018] The lower inner brush parts 31D, 31E, and 31F are located below and opposite the upper inner brush parts 31A, 31B, and 31C, respectively, and are arranged to face the tongue-side tooth surfaces of the mandibular dentition. The lower inner brush parts 31D, 31E, and 31F are arranged in a U-shape with the lower inner brush part 31D in the center and the lower inner brush parts 31E and 31F spaced apart on both sides in the circumferential direction.

[0019] In the inner brush part 31, the inner upper brush part 31B and the inner upper brush part 31C are line-symmetrical in the left-right direction, so a description of the inner upper brush part 31C may be omitted. Also, the inner lower brush parts 31D, 31E, and 31F are line-symmetrical in the meshing direction with the inner upper brush parts 31A, 31B, and 31C, respectively, so a description of the inner lower brush parts 31D, 31E, and 31F may be omitted.

[0020] The inner upper brush part 31A is positioned at the center in the circumferential direction. When viewed from above, the inner upper brush part 31A has a portion that is curved in the circumferential direction in a direction that convexes outward. Both sides of the inner upper brush part 31A are curved in the circumferential direction. The inner upper brush part 31A is positioned mainly to face the tongue-side tooth surfaces of multiple front teeth on the maxillary side. Therefore, multiple brush parts 30 are arranged in the circumferential direction, the occlusal direction, and the depth direction.

[0021] FIG. 3 is a cross-sectional view taken along the CC line in FIG. 1 . As shown in FIG. 3 , the inner upper brush part 31A includes a base part 41, a filament 42, and a connecting part 43. The base part 41 has a rectangular cross section. FIG. 4 is a top view of the inner upper brush part 31A. As shown in FIG. 4 , the base part 41 has portions on both sides of the circumferential direction that curve outward in a top view. This embodiment uses a brush part 30 that is aligned with the dentition and is designed to be moved manually or electrically. Therefore, the curvature of the base part 41 allows the filament 42 to align with the lingual side of the dentition, improving cleaning performance and fit. Furthermore, it is possible to maximize the installation area of ​​the brush part 30, which, in the case of an electrically operated toothbrush, contributes to improved vibration efficiency and cleaning power.

[0022] The numerical specifications given as examples for the inner upper brush portion 31A in the following description are applicable to the inner brush portion 31 and the outer brush portion 32 of the brush portion 30 unless otherwise specified.

[0023] When the length of the base portion 41 in the circumferential direction is 15 mm or more, it is preferable that the base portion 41 be curved along the circumferential direction. When the length of the base portion 41 is less than 15 mm, there is less advantage to curving the base portion 41 itself, so it is sufficient to arrange multiple linearly extending base portions 41 along the curved contour. If the length of the base portion 41 exceeds 150 mm, it will be too large for the oral cavity size, reducing operability and fit, so it is preferable that the length be 150 mm or less.

[0024] When the radius of curvature of the mouthpiece portion 20 is 5 mm or more and 50 mm or less, it is preferable to curve the base portion 41. When the radius of curvature of the mouthpiece portion 20 is less than 5 mm, it becomes difficult to fit the support 50, and the bristle pitch of the filaments 42 changes excessively, which may cause interference between the bristle ends or make them sparse. Therefore, it is preferable to arrange multiple brush portions 30 along the contour of the curved base portion 41. When the radius of curvature of the mouthpiece portion 20 exceeds 50 mm, it can be considered to have a straight shape.

[0025] The length L of the base portion 41 is defined as the linear distance connecting both ends of the brush surface 41a in the circumferential direction. The length L of the base portion 41 is preferably 5 mm or more, and more preferably 15 mm or more. By making the length L of the base portion 41 5 mm or more, it is easy to feel a good fit, and in the case of an electric toothbrush, vibrations are less likely to attenuate, making them more easily transmitted to the extremities, thereby improving cleaning performance. It is preferable that the brush portion 30 includes a base portion 41 whose length L is at least twice the width, which is the dimension of the base portion 41 in the meshing direction. By prioritizing the length L over the width of the base portion 41, it is possible to unify the texture and fit across teeth or areas (front teeth, back teeth, etc.).

[0026] The base portion 41 is detachably fitted from the outside into a fitting recess 61A (described in detail later) in the inner support body 51. The base portion 41 is connected to the inner support body 51 by fitting the upper and lower surfaces forming the connecting portion 43 into the fitting recess 61A. The detachable fitting of the base portion 41 into the fitting recess 61A makes the inner upper brush portion 31A replaceable with respect to the inner support body 51. This allows users to change the brush portion 30 and change the specifications according to their preferences and situations, making it possible to meet a wide range of needs.

[0027] The thickness of the base 41, which is the depth dimension, is preferably 1 mm or more, and more preferably 2 mm or more. The thickness of the base 41, which is the depth dimension, is preferably 5 mm or less, and more preferably 4 mm or less. The upper and lower limits of the thickness, which is the depth dimension of the base 41, can be arbitrarily combined. Furthermore, if the bonding strength between the base 41 and the inner support 51 can be ensured, the thickness of the base 41 is preferably 0.3 to 1.2 mm. By setting the depth thickness of the base 41 to 1 mm or more and 5 mm or less, the base 41 can be stably fitted and coupled to the fitting recess 61A. If the bonding strength between the base 41 and the inner support 51 can be ensured, a thickness of the base 41 of 0.3 to 1.2 mm prevents the volume from becoming excessively large, which contributes to preventing drooling, improving operability, and improving fit. The depth-wise thickness of the base portion 41 is preferably 50% to 90% of the depth-wise dimension of the inner support body 51. The depth-wise thickness of the inner support body 51 is the sum of the depth of the fitting recess 61A and the thickness of the thin-walled portion located inside the fitting recess 61A. By setting the depth-wise thickness of the base portion 41 to 50% to 90% of the depth-wise thickness of the inner support body 51, the base portion 41 is stably fixed to the inner support body 51 and, in the case of an electric device, the thickness is sufficient for efficient transmission of vibrations. Furthermore, since the volume is not excessively large, this contributes to preventing drooling, improving operability, and improving fit.

[0028] The filaments 42 extend outward from the brush surface 41a facing outward on the base 41. The brush surface 41a has a portion that is curved circumferentially in a direction that convexly faces outward when viewed from above. The filaments 42 include a filament 42A that extends outward from the upper end of the brush surface 41a, a filament 42B that extends outward from a position below the filament 42A, and a filament 42C that extends outward from a position below the filament 42B.

[0029] If the position where the upper and lower teeth occlude in the occlusal direction is defined as occlusal surface K, the inclination angle of the filaments 42 relative to the occlusal surface K becomes smaller the closer they are to the occlusal surface K in a side view parallel to the occlusal surface K, and becomes larger the farther they are from the occlusal surface K. Specifically, the inclination angle of the filament 42A, which is closer to the gums and farthest from the occlusal surface K, is larger than the inclination angles of the filaments 42B and 42C. The inclination angle of the filament 42C closest to the occlusal surface K is smaller than the inclination angles of the filaments 42A and 42B.

[0030] When the mouthpiece 20 is held in the mouth, the mouth tends to open slightly. Furthermore, the dimension of the tooth surface in the occlusion direction is often larger than the arrangement pitch in the occlusion direction at the base of the filaments 42A and 42C. Therefore, if the inclination angles of the filaments 42A to 42C are the same, it becomes difficult for the tips of the filaments 42A to 42C to cover the entire tooth surface in the occlusion direction. In this embodiment, the inclination angles gradually increase from the filament 42C to the filament 42A. Therefore, even when the mouth tends to open, the filament 42C can fit against the tooth tip on the tongue side, and the filament 42A can fit against the gum side on the tongue side.

[0031] The arrangement pitches of adjacent filaments 42A and 42B in the meshing direction, and the arrangement pitches of adjacent filaments 42B and 42C in the circumferential direction are offset by, for example, half a pitch. That is, when viewed in the direction facing the brush surface 41a, the filaments 42A, 42B, and 42C are arranged in a staggered pattern. By arranging the filaments 42A, 42B, and 42C in a staggered pattern, the gaps between the filaments 42 can be reduced, improving fit to the tooth surface and cleaning performance.

[0032] As shown in FIG. 4 , when viewed from above, the filaments 42 extend radially outward from the brush surface 41a. The inner upper brush section 31A constituting the brush unit 30 has a portion where the base section 41 curves, where the arrangement pitch of the roots of the filaments 42 differs from the arrangement pitch of the bristle tips. Specifically, the arrangement pitch P2 of the bristle tips of the filaments 42 is greater than the arrangement pitch P1 of the roots. By varying the arrangement pitch between the filaments 42 at the roots and the bristle tips, it is possible to adjust the balance between rigidity and flexibility, thereby improving cleaning performance. For example, by reducing the arrangement pitch of the roots of the filaments 42 to ensure bristle stiffness, while increasing the arrangement pitch of the bristle tips, it is possible to ensure the ability to penetrate gaps between teeth and improve cleaning performance.

[0033] When the arrangement pitch P2 of the tip portion is greater than the arrangement pitch P1 of the base portion, the value represented by P2 / P1 is preferably 1.05 or more and 2.00 or less. By setting the value represented by P2 / P1 to 1.05 or more and 2.00 or less, the tip portion of the filament 42 can be formed into an arc that follows the tooth row on the tongue surface, improving fit. Since the pitch of the base portion is denser than that of the tip portion, bristles can be made firm. Note that different arrangement pitches between the tip portion and the base portion and adjustment of P2 / P1 within the above range are not uniquely determined according to the curvature of the base portion 41, and may also be implemented, for example, in a region where the base portion 41 is linear.

[0034] The inner upper brush part 31B is located circumferentially to the right of the inner upper brush part 31A and extends to the circumferential end. The end of the inner upper brush part 31B closer to the inner upper brush part 31A has a shape that is an extension of the curved shape of the inner upper brush part 31A. The -θ side of the inner upper brush part 31B has a linear shape that is tangent to the curved shape. The inner upper brush part 31B is positioned mainly to face the tongue-side tooth surfaces of the maxillary canines and back teeth (premolars and molars).

[0035] FIG. 5 is a side view of the inner upper brush part 31B as viewed from the right side. As shown in FIG. 5, the upper surface of the inner upper brush part 31B is inclined downward as it approaches the -θ side. That is, the width of the inner upper brush part 31B, which is the dimension in the meshing direction, becomes thinner as it moves from the +θ side to the -θ side. Of the filaments 42, filaments 42A and 42B are arranged along the inclination of the upper surface of the inner upper brush part 31B, in a direction that becomes downward as it approaches the -θ side. Of the filaments 42, filament 42C is arranged halfway in the θ direction as the width of the inner upper brush part 31B becomes thinner on the -θ side. Therefore, the filaments 42 are arranged in three rows in the meshing direction on the +θ side and in two rows in the meshing direction on the -θ side.

[0036] 3, the base portion 41 of the lower inner brush part 31D is detachably fitted from the outside into a fitting recess 61D (described in detail later) in the inner support body 51. The base portion 41 is coupled to the inner support body 51 by fitting the upper and lower surfaces forming the connecting portion 43 into the fitting recess 61D. Removably fitting the base portion 41 into the fitting recess 61D makes the lower inner brush part 31D replaceable with respect to the inner support body 51. This allows users to change the brush part 30 and change the specifications according to their preferences and situations, making it possible to meet a wide range of needs.

[0037] The inner lower brush part 31D is vertically symmetrical to the inner upper brush part 31A in the meshing direction, with the meshing surface K as the center. The filaments 42A in the inner lower brush part 31D extend outward from the lower end of the brush surface 41a. The filaments 42B extend outward from a position higher than the filaments 42A. The filaments 42C extend outward from a position higher than the filaments 42B. The inclination angle of the filament 42A, which is closest to the gums and farthest from the meshing surface K, with respect to the meshing surface K is greater than the inclination angles of the filaments 42B and 42C with respect to the meshing surface K. The inclination angle of the filament 42C, which is closest to the meshing surface K, with respect to the meshing surface K is smaller than the inclination angles of the filaments 42A and 42B.

[0038] The outer brush part 32 is located on the outside in the depth direction. The outer brush part 32 includes upper outer brush parts 32A, 32B, 32C, 32D, and 32E and lower outer brush parts 32F, 32G, 32H, 32J, and 32K. The upper outer brush parts 32A, 32B, 32C, 32D, and 32E are located on the upper side and are arranged circumferentially facing the cheek-side tooth surfaces of the maxillary dentition. The upper outer brush parts 32A, 32B, 32C, 32D, and 32E are arranged in a U-shape overall, with the upper outer brush part 32A in the center, the upper outer brush parts 32B and 32C arranged sequentially to the right of the circumferential direction at a distance, and the upper outer brush parts 32D and 32E arranged sequentially to the left of the circumferential direction at a distance.

[0039] The outer lower brush parts 32F, 32G, 32H, 32J, and 32K are located below and opposite the outer upper brush parts 32A, 32B, 32C, 32D, and 32E, respectively, and are arranged to face the cheek-side tooth surfaces of the mandibular dentition. The outer lower brush parts 32F, 32G, 32H, 32J, and 32K are arranged in a U-shape overall, with the outer lower brush part 32F in the center, the outer lower brush parts 32G and 32H arranged sequentially to the right of the outer brush part in a circumferential direction with a gap between them, and the outer lower brush parts 32J and 32K arranged sequentially to the left of the outer brush part in a circumferential direction with a gap between them.

[0040] In the outer brush part 32, the outer upper brush part 32B and the outer upper brush part 32D are line-symmetrical in the left-right direction, and the outer upper brush part 32C and the outer upper brush part 32E are line-symmetrical in the left-right direction, so that the description of the outer upper brush parts 32D and 32E may be omitted. Also, the outer lower brush parts 32F, 32G, 32H, 32J, and 32K are line-symmetrical in the meshing direction with the outer upper brush parts 32A, 32B, 32C, 32D, and 32E, respectively, so that the description of the outer lower brush parts 32F, 32G, 32H, 32J, and 32K may be omitted.

[0041] The outer upper brush part 32A is positioned at the circumferential center. When viewed from above, the outer upper brush part 32A has a portion that curves in the circumferential direction in a direction that convex outward. Both sides of the outer upper brush part 32A are curved in the circumferential direction. The outer upper brush part 32A is positioned mainly to face the cheek-side tooth surfaces of multiple front teeth on the maxillary side.

[0042] As shown in FIG. 3 , the outer upper brush part 32A has a base part 71, a filament 72, and a connecting part 73. The base part 71 has a rectangular cross section. FIG. 6 is a view of the outer upper brush part 32A as viewed from above. As shown in FIG. 6 , the base part 71 has portions on both sides of the circumferential direction that curve outward in a convex manner when viewed from above. The curvature of the base part 71 allows the filament 72 to align with the buccal side of the dentition, improving cleaning performance and fit. Furthermore, it is possible to maximize the installation area, which, in the case of an electric toothbrush, contributes to improved vibration efficiency and cleaning power.

[0043] The base portion 71 is detachably fitted from the inside into a fitting recess 62A (details of which will be described later) in the outer support body 52. ​​The base portion 71 is connected to the outer support body 52 by fitting the upper and lower surfaces, which form the connecting portion 73, into the fitting recess 62A. The detachable fitting of the base portion 71 into the fitting recess 62A makes the outer upper brush portion 32A replaceable with respect to the outer support body 52.

[0044] The filaments 72 extend inward from the brush surface 71a facing inward on the base portion 71. Therefore, the filaments 72 face the filaments 42. The brush surface 71a has a portion that is curved circumferentially in a direction that convex outward when viewed from above. As shown in Figure 3, the filaments 72 include a filament 72A that extends outward from the upper end of the brush surface 71a, a filament 72B that extends outward from a position below the filament 72A, and a filament 72C that extends outward from a position below the filament 72B.

[0045] In a side view parallel to the occlusal surface K, the inclination angle of the filament 72 relative to the occlusal surface K decreases as it approaches the occlusal surface K and increases as it moves away from the occlusal surface K. Specifically, the inclination angle of the filament 72A, which is closer to the gum side and farthest from the occlusal surface K, is greater than the inclination angles of the filaments 72B and 72C. The inclination angle of the filament 72C, which is closest to the occlusal surface K, is smaller than the inclination angles of the filaments 72A and 72B. In this embodiment, because the inclination angles increase sequentially from filament 72C to filament 72A, even when the mouth is slightly open, the filament 72C can fit on the tooth tip side on the cheek side, and the filament 72A can fit on the gum side on the cheek side.

[0046] The arrangement pitches of adjacent filaments 72A and 72B in the meshing direction, and of adjacent filaments 72B and 72C in the circumferential direction are offset by, for example, half a pitch. That is, when viewed in the direction facing the brush surface 71a, the filaments 72A, 72B, and 72C are arranged in a staggered pattern. By arranging the filaments 72A, 72B, and 72C in a staggered pattern, the gaps between the filaments 72 can be reduced, improving fit to the tooth surface and cleaning performance.

[0047] 6, when viewed from above, the filaments 72 extend radially inward from the brush surface 71a. The outer upper brush section 32A constituting the brush unit 30 has a portion where the arrangement pitch of the roots of the filaments 72 is different from the arrangement pitch of the bristle tips at the curved portion of the base 71. Specifically, the arrangement pitch P4 of the bristle tips of the filaments 72 is smaller than the arrangement pitch P3 of the roots.

[0048] By varying the arrangement pitch between the filaments 72 at the root and tip portions, it is possible to adjust the balance between rigidity and flexibility, improving cleaning power. When the arrangement pitch P4 at the tip portions is smaller than the arrangement pitch P3 at the base portions, the value expressed by P4 / P3 is preferably 0.3 or greater and 0.9 or less. By setting the value expressed by P4 / P3 to 0.3 or greater and 0.9 or less, for example, increasing the arrangement pitch at the base portions of the filaments 72 to sparse the filaments and ensure operability, while decreasing the arrangement pitch at the tip portions can form an arc shape that follows the jaw dentition, improving fit. Note that varying the arrangement pitch at the tip portions and the base portions and adjusting P4 / P3 within the above range are not uniquely determined according to the curvature of the base portion 71; for example, this may also be performed in regions where the base portion 71 is linear.

[0049] Returning to Figure 2, the outer upper brush part 32B is located to the right of the outer upper brush part 32A in the circumferential direction. The outer upper brush part 32C is located to the right of the outer upper brush part 32B in the circumferential direction. The circumferential end of the outer upper brush part 32C on the side closer to the outer upper brush part 32B (the +θ side) has a shape that is an extension of the curved shape of the outer upper brush part 32A. The -θ side of the outer upper brush part 32C has a linear shape that is tangent to the curved shape. The outer upper brush part 32C is mainly positioned to face the cheek-side tooth surfaces of multiple molars (premolars, molars) on the maxillary side.

[0050] When viewed from above, the outer upper brush part 32B has a linear shape connecting the -θ side end of the outer upper brush part 32A and the +θ side end of the outer upper brush part 32C. The outer upper brush part 32B is formed in a linear shape because its circumferential dimension is short and, as described above, there is little advantage to curving it.

[0051] Figure 7 is a side view of the outer upper brush parts 32B and 32C as viewed from the inside. As shown in Figure 7, the upper surfaces of the outer upper brush parts 32B and 32C are inclined downward as they approach the -θ side. That is, the width of the outer upper brush parts 32B and 32C, which is the dimension in the meshing direction, becomes thinner as they move from the +θ side to the -θ side. The inclinations of the upper surfaces of the outer upper brush parts 32B and 32C are on the same straight line.

[0052] The filaments 72 in the outer upper brush parts 32B and 32C are arranged along the slope of the upper surface. Because the widths of the outer upper brush parts 32B and 32C are thicker than the width of the inner upper brush part 31B, the filaments 72A, 72B, and 72C are arranged in three rows over the entire circumferential length.

[0053] 3 , the base portion 71 of the outer lower brush part 32F is detachably fitted from the inside into a fitting recess 62F (described in detail later) of the outer support body 52. ​​The base portion 71 is coupled to the outer support body 52 by fitting the upper and lower surfaces, which form the connecting portion 73, into the fitting recess 62F. The detachable fitting of the base portion 71 into the fitting recess 62F makes the outer lower brush part 32F replaceable with respect to the outer support body 52.

[0054] The lower outer brush part 32F is vertically symmetrical in the meshing direction relative to the upper outer brush part 32A, with the meshing surface K as the center. The filaments 72A in the lower outer brush part 32F extend inward from the lower end of the brush surface 71a. The filaments 72B extend inward from a position higher than the filaments 72A. The filaments 72C extend inward from a position higher than the filaments 72B. The inclination angle of the filament 72A, which is closest to the gums and farthest from the meshing surface K, with respect to the meshing surface K is greater than the inclination angles of the filaments 72B and 72C with respect to the meshing surface K. The inclination angle of the filament 72C, which is closest to the meshing surface K, with respect to the meshing surface K is smaller than the inclination angles of the filaments 72A and 72B.

[0055] The distance between the bristle tips of the filaments 42 of the inner brush part 31 and the filaments 72 of the outer brush part 32 varies depending on the circumferential position. The outer brush part 32 and the inner brush part 31 each have a central region including the circumferential center of the support body 50 and end regions located at the circumferential ends of the support body 50. An intermediate region is provided between the central region and the end regions. The central region is a region that mainly faces the front teeth. The end regions are regions that mainly face the premolars to molars. The intermediate region is a region that mainly faces the canines to premolars. As shown in FIG. 1 , in the outer brush part 32, the central region is designated as the first region A1, the intermediate region is designated as the second region A2, and the end regions are designated as the third region A3. In the inner brush part 31, the central region is designated as the first region B1, the intermediate region is designated as the second region B2, and the end regions are designated as the third region B3.

[0056] The distance between the bristle tips between the first region A1 and the first region B1 is D1, the distance between the bristle tips between the second region A2 and the second region B2 is D2, and the distance between the bristle tips between the third region A3 and the third region B3 is D3. The distance between the bristle tips D1 is the distance between the filament 72 with the shortest bristle length in the outer brush portion 32 in the first region A1 and the filament 42 with the shortest bristle length in the inner brush portion 31 in the first region B1. The distance between the bristle tips D2 is the distance between the filament 72 with the shortest bristle length in the outer brush portion 32 in the second region A2 and the filament 42 with the shortest bristle length in the inner brush portion 31 in the second region B2. The distance between the bristle tips D3 is the distance between the filament 72 with the shortest bristle length in the outer brush portion 32 in the third region A3 and the filament 42 with the shortest bristle length in the inner brush portion 31 in the third region B3. The shortest distance between bristles is the value measured as the distance between the shortest bristles in the depth direction between the inner and outer bristles on the same plane perpendicular to the circumferential direction (i.e., a plane extending in the depth direction) based on the inner support 51. The distance between bristles is a value measured when viewed in the meshing direction (e.g., from above). In other words, the positions of the bristles measured as the distance between bristles may be different in the meshing direction. Note that if the bristles with the shortest depth direction do not lie on the same plane perpendicular to the circumferential direction, the plane is considered to be a virtual space with a thickness of ±0.5 mm in the circumferential direction, and the bristles are considered to be on the same plane if they fit within this virtual space. In other words, the bristles with the shortest depth direction are considered to be on the same plane if the circumferential separation distance is within 1.0 mm. By dividing the brush part 30 into multiple areas with different distances between the bristles corresponding to the areas in the oral cavity, it is possible to create specifications suitable for cleaning each area (improved bristle stiffness, setting a step profile that matches the shape of the teeth), and each area in the oral cavity can be thoroughly cleaned.

[0057] The bristle tip distances D1 and D3 satisfy the relationship D3 > D1. In other words, the bristle tip distance D3 in the area facing mainly molars, including premolars and molars, is greater than the bristle tip distance D1 in the area facing mainly front teeth. By setting the bristle tip distance to match the size of the teeth in each area, such as front teeth being thin and therefore having a small interdental distance, and back teeth being thick and therefore having a large interdental distance, the fit to the dentition and cleaning power can be improved. It is preferable that the bristle tip distances D1, D2, and D3 satisfy the relationship D3 > D2 > D1. In other words, the depthwise gap between the outer brush part 32 and the inner brush part 31 is larger in the second areas A2 and B2 than in the first areas A1 and B1, and larger in the third areas A3 and B3 than in the second areas A2 and B2.

[0058] The vibrations generated by the electric drive unit are due to the rotational motion of the shaft 14, and the amplitude is larger in the third regions A3 and B3, which have a larger radius of rotation around the shaft 14. Depending on this vibration characteristic, it is possible to set an optimal space (range of motion) between the bristles.

[0059] When the length from the center to the end in the circumferential direction of the support 50 is taken as 100%, the region from the center to 40% in the circumferential direction is taken as the first region A1, B1, the region from 40% to 65% is taken as the second region A2, B2, and the region from 65% to 100% is taken as the third region A3, B3, it is preferable that the distances D1, D2, D3 between the bristle ends satisfy the relationship D1<D2<D3.

[0060] The bristle strength of the filaments 72 preferably satisfies the relationship of first region A1 < second region A2 < third region A3. The bristle strength of the filaments 42 preferably satisfies the relationship of first region B1 < second region B2 < third region B3. By satisfying these relationships, sufficient cleaning power can be ensured even for back teeth that rarely come into contact with the filaments 42, 72.

[0061] The thickness of the filament 72 preferably satisfies the relationship of first region A1 < second region A2 < third region A3. The thickness of the filament 42 preferably satisfies the relationship of first region B1 < second region B2 < third region B3. By satisfying the above relationships, sufficient cleaning power can be ensured even for back teeth that rarely come into contact with the filaments 42, 72.

[0062] The longest bristle length of the filament 72 preferably satisfies the relationship of first region A1 < second region A2 < third region A3. The longest bristle length of the filament 42 preferably satisfies the relationship of first region B1 < second region B2 < third region B3. By satisfying the above relationships, it is possible to ensure the ability to penetrate deep into molars and cleaning power.

[0063] Each brush section 30 has filaments 42, 72 arranged in the circumferential direction, each having a different bristle length and a step (bristle height step). The bristle height step arrangement profile differs at least between the second region A2 and the third region A3 and between the second region B2 and the third region B3. The maximum bristle height step preferably satisfies the relationships of the second region A2 < the third region A3 and the second region B2 < the third region B3. Furthermore, when the bristle height step arrangement profile is repeated at a constant period, the period preferably satisfies the relationships of the second region A2 < the third region A3 and the second region B2 < the third region B3. For example, if the longest filament 42, 72 is designated "long" and the shortest filament 42, 72 is designated "short," an arrangement profile is set in which "short, short, short, long, long" is repeated in the second region A2, B2, and "short, short, short, short, long, long" is repeated in the third region A3, B3. By satisfying the above relationship, it is possible to ensure the ability to penetrate deep into molars and cleaning power, and it is also possible to change the period of the arrangement profile according to the size of the teeth, thereby improving the fit.

[0064] The total number of filaments 42, 72 in each brush section 30 is preferably 10 to 150. If the total number of filaments 42, 72 is less than 10, the scraping force is insufficient and the cleaning function is reduced. If the total number of filaments 42, 72 exceeds 150, the filaments 42, 72 are densely packed and difficult to bend, resulting in a reduced fit and a reduced cleaning function. By setting the total number of filaments 42, 72 to 10 to 150, the cleaning function and fit can be improved.

[0065] The total number of filaments 72 in the outer brush part 32 is preferably 300 to 1800. The total number of filaments 42 in the inner brush part 31 is preferably 200 to 1400. Because the outer brush part 32 has a wide area facing the row of teeth, by setting the total number of filaments 72 within the above range, it is possible to cover a wide range of the row of teeth.

[0066] The total number of filaments 72 in the second region A2 and the third region A3 on each side is preferably greater than the total number of filaments 72 in the first region A1. Also, the total number of filaments 42 in the second region B2 and the third region B3 on each side is preferably greater than the total number of filaments 42 in the first region B1. By satisfying the above relationship, sufficient cleaning power can be ensured even for back teeth that rarely come into contact with the filaments 42, 72.

[0067] As described above, the brush unit 30 is composed of a plurality of inner brush units 31 and outer brush units 32 in the depth direction. In the meshing direction of the brush unit 30, the inner brush unit 31 is composed of a plurality of inner upper brush units 31A, 31B, and 31C and a plurality of inner lower brush units 31D, 31E, and 31F, and the outer brush unit 32 is composed of a plurality of outer upper brush units 32A, 32B, 32C, 32D, and 32E and a plurality of outer lower brush units 32F, 32G, 32H, 32J, and 32K. In the circumferential direction of the brush unit 30, a plurality of inner brush units 31 and a plurality of outer brush units are composed.

[0068] By configuring the brush unit 30 in multiple units, it is possible to thoroughly clean each area in the oral cavity with specifications suited to the area in the oral cavity (such as improved bristle stiffness and a step profile that matches the shape of the dentition) In particular, in this embodiment, since multiple brush units 30 are configured in each of the depth direction, occlusion direction, and circumferential direction, the cleaning unit can be optimized to more precisely match each area.

[0069] The number of rows of filaments 42, 72 in the interdigitating direction may be two or less. When the number of rows of filaments 42, 72 is two or less, the width of the brush portion 30 in the interdigitating direction is preferably 2 mm or more and 5 mm or less. When the number of rows of filaments 42, 72 is two or more, the width of the brush portion 30 in the interdigitating direction is preferably 2 mm or more and 20 mm or less. The maximum width of the brush portion 30 is determined according to the width of the support 50. When the number of rows of filaments 42, 72 is two or less, increasing the number of brush portions 30 in the interdigitating direction allows for more precise positioning according to the intraoral site. When the number of rows of filaments 42, 72 is two or more, increasing the width of the brush portion 30 increases the rigidity in the width direction, making the brush portion 30 less likely to bend. This improves the cleaning power of the brush portion 30. Furthermore, when the mouthpiece portion 20 is electrically operated, vibration damping can be suppressed even if the circumferential length of the brush portion 30 is increased.

[0070] When multiple brush parts 30 are provided, three or more are preferred in the circumferential direction. When multiple brush parts 30 are provided, nine or fewer are preferred, and seven or fewer are more preferred. When multiple brush parts 30 are provided in the circumferential direction, the upper and lower limit values ​​can be arbitrarily combined. When multiple brush parts 30 are provided, one or more are preferred, and two or more are more preferred, in the intermeshing direction. When multiple brush parts 30 are provided, four or fewer are preferred, and three or fewer are more preferred, in the intermeshing direction. When multiple brush parts 30 are provided in the intermeshing direction, the upper and lower limit values ​​can be arbitrarily combined. As a result, the circumferential direction is broadly divided into three areas: the front, right, and left sides, and can be further subdivided into five areas: the front, right, left, an area intermediate between the front and right sides, and an area intermediate between the front and left sides, allowing for specification designs corresponding to each area. When the width direction is broadly divided into the upper and lower jaws, the specification designs corresponding to the upper and lower jaws can be arbitrarily combined. In this way, by setting an upper limit on the number of brush units 30, it is possible to prevent each brush unit 30 and the surrounding support 50 from moving independently and disorderly, thereby avoiding discomfort. Furthermore, if the mouthpiece unit 20 is electrically operated, vibrations are less likely to be attenuated and are more easily transmitted, improving cleaning performance.

[0071] The circumferential length of the brush unit 30 is preferably 5 mm or more and 150 mm or less. A length of 5 mm corresponds to one of a child's front teeth. A length of 150 mm corresponds to the entire circumferential length of the support body 50 on the outside. If the circumferential length of the brush unit 30 is 5 mm or more, a precise fit can be achieved for even the smallest child's front teeth. If the circumferential length of the brush unit 30 is 150 mm or less, when the mouthpiece unit 20 is manually moved, the excess area that deviates from the dentition is reduced, reducing steric obstructions in the oral cavity and ensuring operability. Furthermore, if the mouthpiece unit 20 is electrically operated, it can be fitted to the entire dentition with reduced vibration damping.

[0072] The brush portion 30 is a first molded body integrally molded from a soft resin. More specifically, the inner brush portion 31 is a first molded body in which a base portion 41, a filament 42, and a connecting portion 43 are integrally molded. The outer brush portion 32 is a first molded body in which a base portion 71, a filament 72, and a connecting portion 73 are integrally molded. Because the brush portion 30 is a first molded body and a separate member from the support body 50, restrictions on the hardness and profile of the brush portion 30 are relaxed, allowing specifications suitable for oral cleaning for each area in the oral cavity (such as improved bristle stiffness and setting a step profile to match the shape of the dentition), and each area in the oral cavity can be thoroughly cleaned.

[0073] Furthermore, because the brush portion 30 is made of a soft resin, it can be easily elastically deformed. Therefore, even if the brush portion 30 curves in the circumferential direction, by molding it into a straight shape and then curving it, it is possible to avoid forcible removal during molding. Furthermore, the bristles of the filaments 42, 72 can also be made to conform to the shape of the jaw, resulting in a high fit. In addition, if the mouthpiece portion 20 is electrically operated, vibrations caused by the electrical current are more easily transmitted, improving cleaning performance.

[0074] Various elastomers can be used as the soft resin that makes up the brush portion 30, including polyurethane and silicone. Polyurethane tends to have higher tensile strength and mechanical abrasion resistance than other elastomers, such as styrene-based or polyester-based elastomers. Therefore, using polyurethane as the soft resin makes it less likely to break even when thin-walled, ensuring mechanical strength and long-term use. Silicone, in particular, has high heat and chemical resistance, reducing deterioration in quality when boiled for disinfection or in the presence of toothpaste.

[0075] At least one of the brush portions 30 is preferably formed from a soft resin having a Shore A hardness of 40 or more, more preferably a soft resin having a Shore A hardness of 70 or more. At least one of the brush portions 30 is preferably formed from a soft resin having a Shore D hardness of 70 or less, more preferably a soft resin having a Shore D hardness of 66 or less. The upper and lower limits of the hardness of the soft resin forming at least one of the brush portions 30 can be arbitrarily combined. "Shore A hardness" refers to the durometer A hardness of plastic measured in accordance with JIS K 7215 or JIS K 6253. "Shore D hardness" refers to the durometer type D hardness specified in JIS K 6253. If the hardness of the soft resin is less than the above lower limit, the scraping force will be insufficient, and if the mouthpiece portion 20 is electrically operated, vibration transmission will also be insufficient, resulting in a reduced cleaning function. If the hardness of the soft resin exceeds the upper limit, the filaments 42, 72 and the bases 41, 71 will be less flexible, and the fit will be reduced, resulting in a decrease in cleaning performance.

[0076] In this embodiment, the brush part 30 is the first molded body, which makes it possible to avoid forcible removal during molding. This allows for the use of a resin with a higher hardness than when the brush part 30 and the support body 50 are integrally molded. Therefore, in this embodiment, the filaments 42, 72 are hard enough to remove plaque, thereby improving cleaning performance. Furthermore, to minimize the volume occupied in the oral cavity, a shorter bristle length than that of a typical integrally molded toothbrush is preferable. In this embodiment, by specifying an upper limit on the hardness of the brush part 30, the filaments 42, 72 can bend and move even with a relatively short bristle length.

[0077] 8 and 9 are external perspective views of the support body 50 in the first embodiment of the mouthpiece portion 20. Fig. 8 is a perspective view of the support body 50 as seen from the inside in the depth direction. Fig. 9 is a cross-sectional view taken along line E-E in Fig. 8, which is a perspective cross-sectional view of the support body 50 as seen from the outside in the depth direction. The shaft 14 is not shown in Fig. 8.

[0078] The support body 50 supports the brush unit 30 in the circumferential direction. As shown in Figures 8 and 9, the support body 50 has an inner support body 51, an outer support body 52, and a connecting portion 53.

[0079] The inner support body 51 is formed in a U-shape when viewed from above. The inner support body 51 has an upper wall portion 54 located at the upper end and extending in the circumferential direction, a lower wall portion 55 located at the lower end and extending in the circumferential direction, an intermediate wall portion 56 located between the upper wall portion 54 and the lower wall portion 55 in the meshing direction and extending in the circumferential direction, and connecting wall portions 57, 58, and 59 extending in the meshing direction and connecting the upper wall portion 54 and the lower wall portion 55 via the intermediate wall portion 56. The upper wall portion 54, the lower wall portion 55, and the intermediate wall portion 56 are arranged over the entire circumferential direction. The connecting wall portion 57 and the connecting wall portion 58 are arranged with a gap in the circumferential direction. The connecting wall portion 59 is formed at each end in the circumferential direction.

[0080] The inner support body 51 has upper mating recesses 61A, 61B, and 61C and lower mating recesses 61D, 61E, and 61F. The mating recesses 61A, 61B, and 61C and the mating recesses 61D, 61E, and 61F are recessed inward from the surface of the inner support body 51 facing outward in the depth direction.

[0081] In the inner supporting body 51, the fitting recesses 61B and 61C are line-symmetrical in the left-right direction, and therefore, the description of the fitting recess 61C may be omitted or simplified. Also, the fitting recesses 61D, 61E, and 61F are line-symmetrical in the meshing direction with the fitting recesses 61A, 61B, and 61C, respectively, and therefore, the description of the fitting recesses 61D, 61E, and 61F may be omitted or simplified.

[0082] 3, the base portion 41 of the inner upper brush part 31A is removably fitted into the fitting recess 61A from the outside. In the fitting recess 61A, the upper wall portion 54 and the intermediate wall portion 56 are fitted into the connecting portion 43 of the inner upper brush part 31A in the meshing direction, and the connecting wall portions 57 and 58 are fitted into both ends of the base portion 41 in the circumferential direction, thereby removably joining the inner upper brush part 31A.

[0083] The base portion 41 of the inner upper brush part 31B is removably fitted into the fitting recess 61B from the outside. In the fitting recess 61B, the upper wall portion 54 and the intermediate wall portion 56 are fitted into the connecting portion 43 of the inner upper brush part 31B in the meshing direction, and the connecting wall portions 57 and 59 are fitted into both ends of the base portion 41 in the circumferential direction, thereby removably joining the inner upper brush part 31B.

[0084] The base 41 of the lower inner brush part 31D is removably fitted into the fitting recess 61D from the outside. In the fitting recess 61D, the lower wall 55 and the intermediate wall 56 are fitted into the connecting part 43 of the lower inner brush part 31D in the meshing direction, and the connecting wall 57 and the connecting wall 58 are fitted into both ends of the base 41 in the circumferential direction, thereby removably joining the lower inner brush part 31D.

[0085] The base 41 of the inner upper brush part 31C is removably fitted into the fitting recess 61C from the outside. The base 41 of the inner lower brush part 31E is removably fitted into the fitting recess 61E from the outside. The base 41 of the inner lower brush part 31F is removably fitted into the fitting recess 61F from the outside.

[0086] The outer support body 52 is U-shaped when viewed from above. The outer support body 52 has an upper wall portion 64 located at its upper end and extending in the circumferential direction, a lower wall portion 65 located at its lower end and extending in the circumferential direction, an intermediate wall portion 66 located between the upper wall portion 64 and the lower wall portion 65 in the meshing direction and extending in the circumferential direction, and connecting wall portions 67, 68, 69, 70, and 52A extending in the meshing direction and connecting the upper wall portion 64 and the lower wall portion 65 via the intermediate wall portion 66. The upper wall portion 64, the lower wall portion 65, and the intermediate wall portion 66 are arranged over the entire circumferential direction. The connecting wall portions 67 and 68 are arranged with a gap in the circumferential direction. The connecting wall portions 69 and 70 are arranged circumferentially outside the connecting wall portions 67 and 68, respectively. The connecting wall portions 52A are formed at both circumferential ends. The intermediate wall portion 66 is located at the same position in the meshing direction as the intermediate wall portion 56 .

[0087] The outer support body 52 has upper mating recesses 62A, 62B, 62C, 62D, and 62E and lower mating recesses 62F, 62G, 62H, 62J, and 62K. The mating recesses 62A, 62B, 62C, 62D, and 62E and the mating recesses 62F, 62G, 62H, 62J, and 62K are recessed outward from the surface of the outer support body 52 that faces inward in the depth direction.

[0088] In the outer supporting body 52, the fitting recesses 62B and 62D are line-symmetric in the left-right direction, and the fitting recesses 62C and 62E are line-symmetric in the left-right direction, so descriptions of the fitting recesses 62D and 62E may be omitted or simplified. Also, the fitting recesses 62F, 62G, 62H, 62J, and 62K are line-symmetric in the meshing direction with the fitting recesses 62A, 62B, 62C, 62D, and 62E, respectively, so descriptions of the fitting recesses 62F, 62G, 62H, 62J, and 62K may be omitted or simplified.

[0089] 3, the base portion 71 of the outer upper brush part 32A is detachably fitted from the inside into the fitting recess 62A. In the fitting recess 62A, the upper wall portion 64 and the intermediate wall portion 66 are fitted in the meshing direction with the connecting portion 73 of the outer upper brush part 32A, and the connecting wall portions 67 and 68 are fitted in the circumferential direction with both ends of the base portion 71, thereby detachably joining the outer upper brush part 32A.

[0090] The base portion 71 of the outer upper brush part 32B is detachably fitted into the fitting recess 62B from the inside. In the fitting recess 62B, the upper wall portion 64 and the intermediate wall portion 66 are fitted into the connecting portion 73 of the outer upper brush part 32B in the meshing direction, and the connecting wall portions 67 and 69 are fitted into both ends of the base portion 71 in the circumferential direction, thereby detachably joining the outer upper brush part 32B.

[0091] The base portion 71 of the outer upper brush part 32C is detachably fitted into the fitting recess 62C from the inside. In the fitting recess 62C, the upper wall portion 64 and the intermediate wall portion 66 are fitted into the connecting portion 73 of the outer upper brush part 32C in the meshing direction, and the connecting wall portion 69 and the connecting wall portion 52A are fitted into both ends of the base portion 71 in the circumferential direction, thereby detachably joining the outer upper brush part 32C.

[0092] The base portion 71 of the lower outer brush part 32F is detachably fitted into the fitting recess 62F from the inside. In the fitting recess 62F, the lower wall portion 65 and the intermediate wall portion 66 are fitted into the connecting portion 73 of the lower outer brush part 32F in the meshing direction, and the connecting wall portions 67 and 68 are fitted into both ends of the base portion 71 in the circumferential direction, thereby detachably joining the lower outer brush part 32F.

[0093] The base portion 71 of the outer upper brush part 32D is detachably fitted into the fitting recess 62D from the inside. The base portion 71 of the outer upper brush part 32E is detachably fitted into the fitting recess 62E from the inside. The base portion 71 of the outer lower brush part 32G is detachably fitted into the fitting recess 62G from the inside. The base portion 71 of the outer lower brush part 32H is detachably fitted into the fitting recess 62H from the inside. The base portion 71 of the outer lower brush part 32J is detachably fitted into the fitting recess 62J from the inside. The base portion 71 of the outer lower brush part 32K is detachably fitted into the fitting recess 62K from the inside.

[0094] The depth direction thickness of the inner support body 51 and the outer support body 52 is preferably 1.5 mm or more and 6 mm or less. By setting the depth direction thickness of the inner support body 51 and the outer support body 52 to 1.5 mm or more and 6 mm or less, the base portions 41, 71 are sufficiently thick to be stably fixed to the inner support body 51 and the outer support body 52, and the volume does not become excessively large, which contributes to preventing drooling and improving operability. Note that the depth direction thickness of the inner support body 51 and the outer support body 52 is the thickness at positions where the fitting recesses 61A, 61B, 61C, 61D, 61E, and 61F and the fitting recesses 62A, 62B, 62C, 62D, 62E, 62F, 62G, 62H, 62J, and 62K are not provided.

[0095] The connecting portion 53 connects the inner support body 51 and the outer support body 52 in the depth direction. The connecting portion 53 connects the inner support body 51 and the outer support body 52 at both ends in the circumferential direction. The connecting portion 53 in this embodiment constitutes the support body 50 as a second molded body integrally molded with the inner support body 51 and the outer support body 52. ​​Note that the connecting portion 53 may be manufactured separately from the inner support body 51 and the outer support body 52 without being integrally molded with them, and may be configured to be joined to the support body 50 in the same way as the brush portion 30, or may be configured to be fixed to the support body 50 with an adhesive or the like.

[0096] The connecting portion 53 has a connecting plate 53A and a filament 53B. The connecting plate 53A is plate-shaped and perpendicular to the meshing direction, extending to the lower end in the circumferential direction. The inner end of the connecting plate 53A is connected to the intermediate wall portion 56 of the inner support body 51. The outer end of the connecting plate 53A is connected to the intermediate wall portion 66 of the outer support body 52.

[0097] The filaments 53B extend protruding in the interdental direction from the upper and lower surfaces of the connecting plate 53A. The filaments 53B have a mountain-shaped bristle height profile with a peak at the midpoint in the depth direction. The mountain-shaped bristle height profile of the filaments 53B results in a profile that fits the interdental surfaces of the teeth, improving cleaning power. The filaments 53B are positioned, for example, in a position facing the molars. Because the filaments 53B are positioned in a position facing the molars and protrude upward and downward, they can effectively clean the interdental surfaces of the molars, which are difficult for the brush unit 30 to reach.

[0098] As described above, the support body 50 is a second molded body in which the inner support body 51, the outer support body 52, and the connecting portion 53 are integrally molded. Because the support body 50 is a second molded body molded as a separate member from the brush portion 30, which is the first molded body, the support body 50 is not restricted by the brush portion 30, and the support body 50 can be made to expand appropriately, neither too tight nor too loose. This improves the fit of the support body 50 to the dentition.

[0099] The support body 50 is a second molded body integrally molded from a resin harder than the brush part 30. Because the support body 50 is harder than the brush part 30, the shape of the support body 50 can be stabilized, allowing it to fit securely to the dentition and ensuring cleaning power. Furthermore, because the support body 50 is harder than the brush part 30, the brush part 30 can be firmly fixed. Furthermore, if the mouthpiece part 20 is electrically operated, vibrations are more likely to be transmitted.

[0100] The resin constituting the support 50 may be a soft resin having a Shore A hardness of 75 or more and a Shore D hardness of 75 or less. If the hardness of the support 50 is lower than the above lower limit, the shape of the support 50 cannot be stabilized, and the fit to the dentition and cleaning power will also decrease. In addition, vibrations will not be transmitted easily, making it difficult to fix the brush part 30. Furthermore, if the mouthpiece part 20 is electrically operated, vibrations will also not be transmitted easily. If the hardness of the support 50 is higher than the above upper limit, the ability to follow the dentition during brushing will be impaired. In addition, it will be difficult to insert and remove the support 50 from the oral cavity. It is preferable that the Shore A hardness of the support 50 is 5 or more higher than that of the brush part 30. This will enhance the above effects.

[0101] As the soft resin constituting the support 50, various elastomers can be used, including the above-mentioned polyurethane and silicone.

[0102] Of the contours of the inner support 51 and the outer support 52 that constitute the support 50, the region that is separated is preferably 20% or more, and more preferably 30% or more. Of the contours of the inner support 51 and the outer support 52 that constitute the support 50, the region that is separated is preferably 70% or less, and more preferably 60% or less. Of the contours of the inner support 51 and the outer support 52 that constitute the support 50, the upper and lower limit values ​​for the region that is separated can be arbitrarily combined. If the region that is separated is within the above range, the shape of the support 50 can be stabilized, and it can fit firmly to the dentition and ensure cleaning power.

[0103] The part where the inner support 51 and the outer support 52 are connected is preferably the circumferential center or the occlusal surface of the molars. This prevents excessive deviation in the positional relationship between the inner and outer sides when the mouthpiece 20 is moved, improving its ability to follow the dentition. Furthermore, when the occlusal surfaces of the molars are connected, the occlusion of the molars can be cleaned. Furthermore, when the mouthpiece 20 is electrically operated, vibrations are more easily transmitted, improving cleaning power.

[0104] A method for manufacturing toothbrush 1 having the above-described configuration includes preparing toothbrush 1 having grip portion 10 and mouthpiece portion 20 connected to grip portion 10, mouthpiece portion 20 being a brush portion 30 which is a first molded body, and support body 50 which is a second molded body different from the first molded body and supports brush portion 30 in a circumferential direction centered on axis J extending in the meshing direction, and brush portion 30 having base portions 41, 71, filaments 42, 72 extending from base portions 41, 71, and connecting portions 43, 73 provided on base portions 41, 71 and connected to support body 50, preparing support body 50, and connecting brush portion 30 to support body 50 at connecting portions 43, 73.

[0105] Preparing the brush part 30 includes molding, by injection molding or the like, the inner upper brush parts 31A, 31B, and 31C and the inner lower brush parts 31D, 31E, and 31F that constitute the inner brush part 31. Preparing the brush part 30 also includes molding, by injection molding or the like, the outer upper brush parts 32A, 32B, 32C, 32D, and 32E and the outer lower brush parts 32F, 32G, 32H, 32J, and 32K that constitute the outer brush part 32.

[0106] Preparing the support 50 includes integrally molding the inner support 51, the outer support 52, and the connecting portion 53 by injection molding or the like. If the mouthpiece portion 20 is electric and the shaft 14 is insert-molded, preparing the support 50 includes molding the inner support 51, the outer support 52, the connecting portion 53, and the shaft 14 by injection molding or the like. If the mouthpiece portion 20 is electric and the shaft 14 is fixed after the inner support 51, the outer support 52, and the connecting portion 53 are integrally molded, preparing the support 50 includes integrally molding the inner support 51, the outer support 52, and the connecting portion 53 by injection molding or the like, and fixing the shaft 14.

[0107] Joining the brush unit 30 to the support body 50 includes fitting and joining the base units 41, 71 of the prepared brush units 30 into the fitting recesses 61A, 61B, 61C and 61D, 61E, 61F of the inner support body 51 of the prepared support body 50, and fitting and joining the base units 41, 71 into the fitting recesses 62A, 62B, 62C, 62D, 62E and 62F, 62G, 62H, 62J, 62K of the outer support body 52. ​​By joining and supporting the brush units 30 with the support body 50, the mouthpiece unit 20 is produced in which the brush units 30 are arranged in a U-shape along the circumferential direction, as shown in FIG.

[0108] The connection between the brush unit 30 and the support body 50 is not limited to the side surface of the base unit 41, 71. Fig. 10 is a side view showing a modified example of the connection portion. As shown in Fig. 10, the brush unit 30 may have a shaft-shaped connection portion 43A, 73A on the surface of the base unit 41, 71 that faces the support body 50. When this configuration is adopted, it is sufficient to provide a recess in the support body 50 into which the connection portion 43A, 73A is inserted and fitted.

[0109] Also, as shown in Figure 11, a wrap-around type connection method may be used in which the periphery of the base portions 41, 71 is made into curved connecting portions 43B, 73B, and the support body 50 is provided with a recess 63 that wraps around the connecting portions 43B, 73B from the outer periphery side of the base portions 41, 71.

[0110] The mechanical connection between the brush part 30 and the support 50 may be a claw type such as a snap fit or a screw type, or may be a configuration other than the above where the brush part 30 and the support 50 are connected by a suction cup, a vacuum adsorption type using suction, a thermal adhesive bond such as thermal welding using a heater or ultrasonic waves, an external force type using the attractive force of a magnet, or a chemical bond using the contraction action of the support 50, van der Waals force, or static electricity.

[0111] If the mouthpiece portion 20 is electrically driven, the shaft 14 of the manufactured mouthpiece portion 20 is then connected to the grip portion 10, thereby completing the manufacture of the toothbrush 1.

[0112] As described above, in the toothbrush 1 of this embodiment, the brush head 30 is the first molded body and the support body 50 is the second molded body, so that each can be given an optimal shape, material, etc. without being restricted by the other. As a result, the toothbrush 1 of this embodiment can achieve sufficient cleaning performance for each area in the oral cavity and a good fit of the support body 50 to the dentition.

[0113] [Second Embodiment of Mouthpiece Section 20] Next, a second embodiment of the mouthpiece section 20 will be described with reference to Fig. 12. In this figure, elements that are the same as those in the first embodiment shown in Figs. 1 to 11 are designated by the same reference numerals, and their description will be omitted.

[0114] Fig. 12 is a plan view of the mouthpiece portion 20 as seen from above. In the first embodiment, a configuration was exemplified in which a plurality of inner brush portions 31 and a plurality of outer brush portions 32 were provided. In this embodiment, as shown in Fig. 12, a single inner brush portion 31 having the entire circumferential length is connected to the inner support body 51, and a single outer brush portion 32 having the entire circumferential length is connected to the outer support body 52.

[0115] The inner brush part 31 and the outer brush part 32 may be molded to follow the curvature of the inner support body 51 and the outer support body 52, respectively, or may be molded flat. If the inner brush part 31 and the outer brush part 32 are molded flat, they may be fitted into the fitting recesses and joined together while being curved to follow the curvature of the inner support body 51 and the outer support body 52. ​​The other configurations are the same as those of the first embodiment.

[0116] In this embodiment, in addition to obtaining the same functions and effects as the first embodiment, the number of parts is reduced, which reduces manufacturing costs and simplifies the joining work.

[0117] [Third Embodiment of Mouthpiece Section 20] Next, a third embodiment of the mouthpiece section 20 will be described with reference to Figures 13 and 14. In these figures, elements that are the same as those in the first embodiment shown in Figures 1 to 11 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0118] 13 is a plan view seen from above of a schematic illustration of the mouthpiece portion 20. The mouthpiece portion 20 of this embodiment has an elastic member 81 that elastically deforms the inner support body 51 to curve it in the circumferential direction, and an elastic member 82 that elastically deforms the outer support body 52 to curve it in the circumferential direction.

[0119] The elastic members 81, 82 are formed of leaf springs, wires, or the like that curve and extend in the circumferential direction. The elastic members 81, 82 have a higher hardness than the inner brush portion 31 and outer brush portion 32 that make up the brush unit 30 and the inner support body 51 and outer support body 52 that make up the support body 50. Materials such as silicone, urethane, acrylic, copper plate, and stainless steel are preferred for the elastic members 81, 82, with materials other than stainless steel being more preferable in terms of adhesiveness and recyclability. Furthermore, using the above materials provides strength and appropriate tension.

[0120] The circumferential length of the elastic members 81, 82 may be the same as the circumferential length of the inner support body 51 and the outer support body 52, or may be the length of the curved region of the inner support body 51 and the outer support body 52.

[0121] The elastic member 81 is attached to the inside of the inner support body 51. The elastic member 82 is attached to the outside of the outer support body 52. ​​It is preferable that the exposed surfaces of the elastic members 81 and 82 are coated with silicone. Because the surfaces of the elastic members 81 and 82 are not exposed, they do not cause discomfort or strange feeling.

[0122] Figure 14 is a side view schematically showing the mouthpiece unit 20 before the elastic members 81, 82 are attached. As shown in Figure 14, the inner support body 51 and the outer support body 52 are molded into a planar shape. The inner brush unit 31 and the outer brush unit 32 are joined to the planar inner support body 51 and the outer support body 52, respectively. Because the inner support body 51 and the outer support body 52 are molded into a planar shape, the mold structure for molding can be simplified, manufacturing costs can be reduced, and the joining process can be facilitated.

[0123] The inner support body 51 to which the inner brush part 31 is connected is elastically deformed and curved in the circumferential direction by the elastic force when the elastic member 81 is attached. The curved inner support body 51 is subjected to outward tension, improving its fit to the lingual dentition and cleaning power. The outer support body 52 to which the outer brush part 32 is connected is elastically deformed and curved in the circumferential direction by the elastic force when the elastic member 82 is attached. The curved outer support body 52 is subjected to inward tension, improving its fit to the cheek dentition and cleaning power.

[0124] In this embodiment, in addition to achieving the same effects and advantages as the first embodiment, the U-shape and angle of the inner support body 51 and the outer support body 52 can be adjusted independently of each other. Therefore, in this embodiment, the angle of the U-shape can be set to correspond to the dentition or each part of the teeth, allowing for specifications suited to oral cleaning for each part, and each part of the oral cavity can be thoroughly cleaned. Furthermore, the fit to the dentition can be improved.

[0125] The thickness of the elastic members 81, 82 is preferably 0.5 mm or more and 3.0 mm or less. When the thickness is equal to or more than the lower limit, the elastic members 81, 82 have sufficient strength, and when the thickness is equal to or less than the upper limit, the elastic members 81, 82 have a compact volume and can obtain the above-mentioned effects while ensuring operability.

[0126] [Fourth Embodiment of Mouthpiece Section 20] Next, a fifth embodiment of the mouthpiece section 20 will be described with reference to Figures 15 and 16. In these figures, elements that are the same as those in the second embodiment shown in Figure 12 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0127] 15 is a plan view seen from above of a schematic view of the mouthpiece portion 20. As in the third embodiment, the mouthpiece portion 20 of this embodiment has an elastic member 81 that elastically deforms the inner supporting body 51 to curve it in the circumferential direction, and an elastic member 82 that elastically deforms the outer supporting body 52 to curve it in the circumferential direction.

[0128] Figure 16 is a side view schematically showing the mouthpiece unit 20 before the elastic members 81, 82 are attached. As shown in Figure 16, the inner support body 51 and the outer support body 52 are molded into a planar shape. The inner brush unit 31 and the outer brush unit 32 are joined to the planar inner support body 51 and the outer support body 52, respectively. The other configurations are the same as those of the first embodiment.

[0129] In this embodiment, in addition to obtaining the same functions and effects as those of the second embodiment, the inner supporting body 51 and the outer supporting body 52 are molded into a planar shape, which simplifies the mold structure for molding, reduces manufacturing costs, and makes it easier to join the components.

[0130] While the preferred embodiments of the toothbrush and toothbrush manufacturing method according to the first embodiment have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0131] For example, in the above embodiment, the inner support 51 and the outer support 52 are configured to be continuous in the circumferential direction, but the present invention is not limited to this configuration, and may alternatively be configured, for example, so that the locations supporting the brush unit 30 are arranged intermittently in the circumferential direction. When this configuration is adopted, for example, the connecting portion 53 may be arranged over the entire circumferential direction, the inner support 51 may be arranged intermittently inside the connecting portion 53, and the outer support 52 may be arranged intermittently outside the connecting portion 53. Furthermore, instead of being configured so that the mouthpiece unit 20 is provided over the entire circumferential direction, it may alternatively be configured so that the mouthpiece unit 20 is provided only in one of the left and right regions, and the connecting portion 53 is also provided only in that region.

[0132] Furthermore, similar to the connecting plate 53A described in the above embodiment, a flat protrusion may be provided from at least one of the inner support body 51 and the outer support body 52 toward the other. The protrusion may connect the inner support body 51 and the outer support body 52. ​​By providing the protrusion, the meshing surfaces of the teeth can be rubbed, improving cleaning power. The thickness of the protrusion is preferably 0.5 to 3.0 mm.

[0133] Second Embodiment of Toothbrush A second embodiment of a toothbrush and a method of manufacturing the toothbrush will now be described with reference to FIGS. 17 to 24. FIG.

[0134] 17 is a front view of toothbrush 101 of the second embodiment. Toothbrush 101 is a mouthpiece-type toothbrush and has a grip portion 110 and a connector 120. Hereinafter, connector 120 will be referred to as mouthpiece portion 120. Vibrations are imparted to connector 120 via grip portion 110. A shaft 114 protrudes from grip portion 110 and is connected to mouthpiece portion 120. Note that a configuration in which shaft 114 protruding from mouthpiece portion 120 is connected to grip portion 110 may also be adopted. Vibrations are imparted to connector 120 from grip portion 110 via shaft 114.

[0135] The present invention can be applied to any of a configuration in which a brushing action is manually applied from the grip portion 110 to the mouthpiece portion 120 in the up / down, left / right, front / back directions, or a combination thereof, a configuration in which vibration is manually applied, and a configuration in which vibration is electrically applied from the grip portion 110 to the mouthpiece portion 120.

[0136] In this embodiment, an electric drive unit is provided in the grip portion 110, and vibrations generated by the drive of the electric drive unit are imparted to the connecting body 120. The electric drive unit includes a power supply unit 111, a vibration element 112, and a control unit 13. The control unit 13 drives the vibration element 112 using power from the power supply unit 111. The power supply unit 111 is configured, for example, as a rechargeable battery or a cell. The vibration element 112 is configured, for example, as a piezoelectric element, an electromagnetic acoustic transducer, an unbalanced motor, or the like. The vibrations generated by the vibration element 112 are vibrations that rotate around an axis extending in the depth direction, and repeatedly reverse their rotational direction at a predetermined rotation angle. A shaft 114 connected to the electric drive unit in the grip portion 110 vibrates by repeatedly reversing its rotational direction. When the vibration element 112 drives the shaft 114, the mouthpiece portion 120 vibrates by repeatedly reversing its rotational direction.

[0137] Mouthpiece portion 120 has brush portion 130 and support body 150. Figure 18 is a view of brush portion 130 in mouthpiece portion 120 as seen from above.

[0138] As shown in Figure 18, the brush units 130 are arranged at separate locations on the outside and inside in the depth direction. The brush unit 130 has an inner brush unit 131 and an outer brush unit 132. The inner brush unit 131 is located on the inside in the depth direction. The inner brush unit 131 has inner upper brush units 131A, 131B, and 131C. The inner upper brush units 131A, 131B, and 131C are located on the upper side and are arranged circumferentially opposite the tongue-side tooth surfaces of the maxillary dentition. The inner upper brush units 131A, 131B, and 131C are arranged in a U-shape, with the inner upper brush unit 131A in the center and the inner upper brush units 131B and 131C arranged on both sides of the circumferential direction at a distance. In the inner brush portion 131, the inner upper brush portion 131B and the inner upper brush portion 131C are line-symmetrical in the left-right direction, and therefore, a description of the inner upper brush portion 131C may be omitted.

[0139] The inner brush part 131 also has lower inner brush parts 131D, 131E, and 131F located below. The lower inner brush parts 131D, 131E, and 131F are symmetrical to the upper inner brush parts 131A, 131B, and 131C in the meshing direction and overlap the upper inner brush parts 131A, 131B, and 131C, respectively, when viewed from above. Therefore, in Fig. 18, the reference numerals of the lower inner brush parts 131D, 131E, and 131F are added in parentheses to the reference numerals of the upper inner brush parts 131A, 131B, and 131C.

[0140] The lower inner brush parts 131D, 131E, and 131F are arranged circumferentially facing the lingual tooth surfaces of the mandibular tooth row. The lower inner brush parts 131D, 131E, and 131F are arranged in a U-shape, with the lower inner brush part 131D in the center and the lower inner brush parts 131E and 131F arranged at intervals on both sides in the circumferential direction. As described above, the lower inner brush parts 131D, 131E, and 131F are line-symmetrical to the upper inner brush parts 131A, 131B, and 131C, respectively, in the meshing direction, and therefore, description of the lower inner brush parts 131D, 131E, and 131F may be omitted.

[0141] The inner upper brush part 131A is disposed at the center position in the circumferential direction. When viewed from above, the inner upper brush part 131A has a portion that is curved in the circumferential direction in a direction that convexes outward. Both sides of the inner upper brush part 131A in the circumferential direction are curved in the circumferential direction. The inner upper brush part 131A is curved in accordance with the curved shape of the support body 150. The inner upper brush part 131A is disposed mainly opposite the tongue-side tooth surfaces of multiple front teeth on the maxillary side. Therefore, multiple brush parts 130 are arranged in the circumferential direction, the occlusal direction, and the depth direction.

[0142] When multiple inner brush parts 131 and multiple outer brush parts 132 are arranged in the circumferential direction, the number is preferably three or more and nine or less, more preferably three or more and seven or less. When multiple inner brush parts 131 and multiple outer brush parts 132 are arranged in the occlusal direction, the number is preferably one or more and four or less, more preferably two or more and three or less. By arranging multiple inner brush parts 131 and multiple outer brush parts 132, it is possible to simultaneously apply bristles to both the buccal and lingual sides of the dentition. Furthermore, the gentle curvature of the inner brush parts 131 and the outer brush parts 132 makes it easier to plant bristles, improving the cleaning experience. Furthermore, the ability to give each inner brush part 131 and each outer brush part 132 different characteristics improves cleaning performance.

[0143] FIG. 19 is a cross-sectional view taken along the CC line in FIG. 17 . As shown in FIG. 19 , the inner upper brush part 131A includes a base part 141, bristle bundles 142, and a connecting part 143. The base part 141 has a rectangular cross section. FIG. 20 is a top view of the inner upper brush part 131A. As shown in FIG. 20 , the base part 141 has portions on both sides of the circumferential direction that curve outward in a top view. This embodiment uses a brush part 130 that is aligned along the dentition and is designed to be moved manually or electrically. Therefore, the curvature of the base part 141 allows the filaments 42 to align with the lingual side of the dentition, improving cleaning performance and fit. Furthermore, it is possible to maximize the installation area of ​​the brush part 130, which, in the case of an electrically operated toothbrush, contributes to improved vibration efficiency and cleaning power.

[0144] The numerical specifications given below for the inner upper brush portion 131A are applicable to the inner brush portion 131 and the outer brush portion 132 of the brush portion 130 unless otherwise specified.

[0145] The length of the base portion 141 in the circumferential direction is preferably 5 mm or more. The length of the base portion 141 in the circumferential direction is preferably shorter than the total circumferential length of the support body 150 (e.g., 130 mm). As shown in FIG. 20 , the length L of the base portion 141 is defined as the linear distance connecting both ends of the brush surface 141a in the circumferential direction. The length L of the base portion 141 is preferably 5 mm or more, and more preferably 15 mm or more. By making the length L of the base portion 141 5 mm or more, it is easy to feel a good fit, and in the case of an electric brush, vibrations are less likely to attenuate, making them more easily transmitted to the extremities, thereby improving cleaning performance.

[0146] When the base portion 141 is curved in the circumferential direction, by giving it a radius of curvature that follows the curvature of the tooth row, it is possible to provide a moderate sense of interlocking without interfering with the movement of the support body 150. The radius of curvature of the base portion 141 is preferably 3 mm or more and 80 mm or less. By setting the radius of curvature of the base portion 141 within the above range, it can move smoothly along the tooth row when moved in the circumferential direction, and can be appropriately interlocked with the movement of the support body 150.

[0147] The base portion 141 is detachably fitted from the outside into a fitting recess 161A (details will be described later) in the inner support body 151. The base portion 141 is coupled to the inner support body 151 by fitting the upper and lower surfaces forming the connecting portion 143 into the fitting recess 161A. The detachable fitting of the base portion 141 into the fitting recess 161A makes the inner upper brush portion 131A replaceable with respect to the inner support body 151. This allows the user to change the brush portion 130 and change the specifications according to their preferences and situations, making it possible to meet a wide range of needs.

[0148] The thickness of the base portion 141, which is the depth dimension, is preferably 6 mm or less, and more preferably 4 mm or less. The thickness of the base portion 141, which is the depth dimension, is preferably 1 mm or more. The upper and lower limits of the thickness of the base portion 141, which is the depth dimension, can be arbitrarily combined. By setting the depth dimension of the base portion 141 to 6 mm or less, the thickness of the support 150 can reduce the feeling of pressure in the oral cavity and make it easier to reach narrow spaces in the oral cavity, such as the back teeth. As a result, the brushing specification is easier to use, improving the cleaning feel and cleaning performance. On the other hand, if the thickness of the base portion 141 is excessively thin, the bristle strength will decrease and vibration transmission will be weakened when used electrically. The width of the base portion 141, which is the dimension in the meshing direction, will be described later.

[0149] It is preferable that there are slits, constrictions, and variations in thickness in the base portion 141. In particular, in the case of a long base portion 141, by having slits, constrictions, and variations in thickness in the base portion 141 itself, the flexibility of the base portion 141 itself is ensured, and a moderate sense of interlocking can be obtained.

[0150] The bristle bundles 142 extend outward from a brush surface 141a facing outward on the base portion 141. The brush surface 141a is inclined inward as it extends upward. Bristle implantation holes 141b are formed in the brush surface 141a. If the position where the upper and lower teeth engage in the meshing direction is defined as meshing surface K, the bristle implantation holes 141b extend at an angle relative to meshing surface K. The bristle implantation holes 141b are inclined upward as they extend outward. Multiple bristle implantation holes 141b (two in FIG. 19 ) are arranged at intervals in the meshing direction. Although not shown, multiple bristle implantation holes 141b are arranged at intervals in the circumferential direction. Therefore, multiple rows of bristle implantation holes 141b are arranged in the meshing direction (two rows in FIG. 19 ).

[0151] The bristle bundles 142 are implanted in the bristle implantation holes 141b. The implantation methods for the bristle bundles 142 include a flat wire method in which the bristle bundle is folded in half and a flat wire sandwiched between the bristle bundles is driven into the bristle implantation holes 141b, a welding method using heat or ultrasonic waves, a method in which the bristle bundles are sandwiched and fixed from both sides and used as the base part 141, or a method in which the bristle bundles are fixed to the base part 141 to form the brush part 130. The flat wire implantation method allows for the production of an ultra-high-density brush part 130, ensuring bristle stiffness and improving cleanability. Furthermore, by including a brush part with bristle bundles 142 arranged 360° around the outer periphery of the base part 141 during the implantation process, a wide variety of designs can be achieved, improving cleanability.

[0152] The bristle bundles 142 are formed from bristles, which improves the cleaning experience. Also, by implanting the bristle bundles 142 in the base 141, arrangement and post-processing are easier than when the bristle bundles 142 are implanted directly in the support 150, thereby improving cleaning performance. Furthermore, by arranging the bristle bundles 142 along the curve of the base 141, the bristle bundles 142 can be applied along the tooth row on the tongue side, further improving cleaning performance.

[0153] The bristle bundles 142 planted in the bristle planting holes 141b of the inner upper brush part 131A extend at an angle upward as they move outward. Therefore, in a bristle bundle row in which multiple bristle bundles 142 are arranged in the circumferential direction, the bristle tips are inclined toward the upper end of the base part 141 relative to the roots. Of the bristle bundle rows aligned in the occlusal direction, the bristle tips of the bristle bundles 142 in the bristle bundle row located at the upper end protrude above the upper surface of the base part 141. This makes it possible to clean a wide area in the occlusal direction, and to thoroughly clean the gums on the tongue side, which are located farther from the occlusal surface K.

[0154] The arrangement pitch of the bristle bundles 142 in the circumferential direction in adjacent bristle bundle rows in the occlusion direction is preferably offset by, for example, half a pitch. In this case, by arranging the bristle bundles 142 in a staggered pattern when viewed in the direction facing the brush surface 141a, the gaps between the bristle bundles 142 can be reduced, improving the fit to the tongue-side tooth surface and cleaning performance.

[0155] When viewed from above, the bristle bundles 142 extend radially outward from the brush surface 141a. As shown in FIG. 20 , the inner upper brush portion 131A constituting the brush unit 130 has a portion where the base portion 141 curves, where the arrangement pitch of the roots of the bristle bundles 142 differs from the arrangement pitch of the tips. Specifically, the arrangement pitch P2 of the tips of the bristle bundles 142 is greater than the arrangement pitch P1 of the roots. By varying the arrangement pitch between the bristle bundles 142 at the roots and tips, it is possible to adjust the balance between rigidity and flexibility, improving cleaning performance. For example, by reducing the arrangement pitch of the roots of the bristle bundles 142, bristle stiffness can be ensured, while by increasing the arrangement pitch of the tips, bristle penetration into interdental gaps can be ensured, improving cleaning performance. Furthermore, the bristle bundles 142 can be applied to cover all teeth from both the front and back, improving the cleaning experience.

[0156] Figure 20 illustrates a configuration in which the arrangement pitch P2 of the bristle tip portions is larger than the arrangement pitch P1 of the base portion at the point where the base portion 141 curves, but regardless of whether the base portion 141 has a curved shape or not, by arbitrarily adjusting the bristle planting angle in the depth direction, it is possible to create a difference in the pitch between the base portion and the tip portion of each bristle bundle 142, thereby achieving the above-mentioned effect and preventing interference between the bristles in the brush portion 130.

[0157] Returning to Figure 18, the inner upper brush part 131B is located circumferentially to the right of the inner upper brush part 131A and extends to the circumferential end. The end of the inner upper brush part 131B closer to the inner upper brush part 131A has a shape that is an extension of the curved shape of the inner upper brush part 131A. The -θ side of the inner upper brush part 131B has a linear shape that is tangent to the curved shape. The inner upper brush part 131B is positioned mainly to face the tongue-side tooth surfaces of the maxillary canines and back teeth (premolars and molars).

[0158] 19 , the base portion 141 of the lower inner brush portion 131D is detachably fitted from the outside into a fitting recess 61D (described in detail below) in the inner support body 151. The base portion 141 is coupled to the inner support body 151 by fitting its upper and lower surfaces, which form the connecting portion 143, into the fitting recess 61D. Removably fitting the base portion 141 into the fitting recess 61D makes the lower inner brush portion 131D replaceable with respect to the inner support body 151. This allows users to change the brush portion 130 and change the specifications according to their preferences and situations, making it possible to meet a wide range of needs.

[0159] The lower inner brush part 131D is vertically symmetrical in the meshing direction to the upper inner brush part 131A, with the meshing surface K as the center. The bristle bundles 142 of the lower inner brush part 131D extend outward from the brush surface 141a. The brush surface 141a is inclined inward as it extends downward. The bristle implantation holes 141b extend at an angle relative to the meshing surface K. The bristle implantation holes 141b are inclined downward as they extend outward.

[0160] The bristle bundles 142 planted in the bristle planting holes 141b of the inner lower brush part 131D extend at an angle downward as they move outward. Therefore, in a bristle bundle row in which multiple bristle bundles 142 are arranged in the circumferential direction, the bristle tips are inclined toward the lower end of the base part 71 relative to the roots. Of the bristle bundle rows aligned in the interdigital direction, the bristle tips of the bristle bundles 142 in the bristle bundle row located at the lower end protrude below the underside of the base part 141. This makes it possible to clean a wide area in the interdigital direction, and to thoroughly clean gums and other areas far from the interdigital surface K.

[0161] The outer brush part 132 is located on the outside in the depth direction. The outer brush part 132 includes outer upper brush parts 132A, 132B, 132C, 132D, and 132E. The outer upper brush parts 132A, 132B, 132C, 132D, and 132E are located on the upper side and are arranged circumferentially facing the cheek-side tooth surfaces of the maxillary dentition. The outer upper brush parts 132A, 132B, 132C, 132D, and 132E are arranged in a U-shape overall, with the outer upper brush part 132A in the center, the outer upper brush parts 132B and 132C arranged sequentially to the right of the circumferential direction at a distance, and the outer upper brush parts 132D and 132E arranged sequentially to the left of the circumferential direction at a distance. In the outer brush portion 132, the outer upper brush portion 132B and the outer upper brush portion 132D are linearly symmetrical in the left-right direction, and the outer upper brush portion 132C and the outer upper brush portion 132E are linearly symmetrical in the left-right direction, so descriptions of the outer upper brush portions 132D and 132E may be omitted.

[0162] The outer brush portion 132 also includes lower outer brush portions 132F, 132G, 132H, 132J, and 132K. The lower outer brush portions 132F, 132G, 132H, 132J, and 132K are symmetrical to the upper outer brush portions 132A, 132B, 132C, 132D, and 132E in the meshing direction and overlap the upper outer brush portions 132A, 132B, 132C, 132D, and 132E, respectively, when viewed from above. Therefore, in Fig. 18, the reference numerals of the lower outer brush portions 132F, 132G, 132H, 132J, and 132K are added in parentheses to the reference numerals of the upper outer brush portions 132A, 132B, 132C, 132D, and 132E.

[0163] The lower outer brush parts 132F, 132G, 132H, 132J, and 132K are arranged circumferentially facing the cheek-side tooth surfaces of the mandibular tooth row. The lower outer brush parts 132F, 132G, 132H, 132J, and 132K are arranged in a U-shape overall, with the lower outer brush part 132F in the center, the lower outer brush parts 132G and 132H arranged sequentially to the right of the center at intervals, and the lower outer brush parts 132J and 132K arranged sequentially to the left of the center at intervals.

[0164] The outer lower brush parts 132F, 132G, 132H, 132J, and 132K are symmetrical to the outer upper brush parts 132A, 132B, 132C, 132D, and 132E in the meshing direction, and therefore descriptions of the outer lower brush parts 132F, 132G, 132H, 132J, and 132K may be omitted.

[0165] The outer upper brush part 132A is positioned at the circumferential center. When viewed from above, the outer upper brush part 132A has a portion that curves in the circumferential direction in a direction that convex outward. Both sides of the outer upper brush part 132A are curved in the circumferential direction. The outer upper brush part 132A is positioned mainly to face the cheek-side tooth surfaces of multiple front teeth on the maxillary side.

[0166] As shown in FIG. 19 , the outer upper brush part 132A has a base part 171, bristle bundles 172, and a connecting part 173. The base part 171 has a rectangular cross section. FIG. 21 is a view of the outer upper brush part 132A as viewed from above. As shown in FIG. 21 , the base part 171 has portions on both sides of the circumferential direction that curve in a direction that convex outward when viewed from above. The curvature of the base part 171 allows the bristle bundles 172 to align with the tongue side of the dentition, improving cleaning performance and fit. It also makes it possible to maximize the installation area, contributing to improved vibration efficiency and cleaning power.

[0167] When the base portion 171 is curved in the circumferential direction, by giving it a radius of curvature that follows the curvature of the tooth row, it is possible to provide a moderate sense of interlocking without interfering with the movement of the support body 150. The radius of curvature of the base portion 171 is preferably 10 mm or more and 80 mm or less. By setting the radius of curvature of the base portion 171 within the above range, it can move smoothly along the tooth row when moved in the circumferential direction, and can be appropriately interlocked with the movement of the support body 150.

[0168] The base portion 171 is detachably fitted from the inside into a fitting recess 162A (details of which will be described later) in the outer support body 152. The upper and lower surfaces of the base portion 171, which form the connecting portion 173, are fitted into the fitting recess 162A, thereby connecting the base portion 171 to the outer support body 152. The detachable fitting of the base portion 171 into the fitting recess 162A makes the outer upper brush portion 132A replaceable with respect to the outer support body 152.

[0169] The bristle bundles 172 extend inward from the inward-facing brush surface 171a of the base portion 171. The brush surface 171a of the outer upper brush portion 132A is inclined outward as it extends upward. Bristle implantation holes 171b are formed in the brush surface 171a. The bristle implantation holes 171b extend at an angle relative to the mating surface K. The bristle implantation holes 171b are inclined upward as they extend inward. Multiple bristle implantation holes 171b (three in FIG. 19 ) are arranged at intervals in the mating direction. Although not shown, multiple bristle implantation holes 171b are arranged at intervals in the circumferential direction. Therefore, multiple rows of bristle implantation holes 141b are arranged in the mating direction (three rows in FIG. 19 ).

[0170] The bristle bundles 172 are implanted in the bristle implantation holes 171b. The implantation method of the bristle bundles 172 is the same as that of the bristle bundles 142. The bristle bundles 172 are formed from standard bristles, thereby improving the cleaning experience. Furthermore, implanting the bristle bundles 172 in the base 171 makes arrangement and post-processing easier than when the bristle bundles 172 are implanted directly in the support 150, thereby improving cleaning performance. Furthermore, arranging the bristle bundles 172 along the curve of the base 171 allows the bristle bundles 172 to be placed along the tooth row on the cheek side, further improving cleaning performance.

[0171] The bristle bundles 172 planted in the bristle planting holes 171b of the outer upper brush part 132A extend at an angle upward as they move inward. Therefore, in a bristle bundle row in which multiple bristle bundles 172 are arranged in the circumferential direction, the bristle tips are inclined toward the upper end of the base part 171 relative to the roots. Of the bristle bundle rows aligned in the occlusal direction, the bristle tips of the bristle bundles 142 in the bristle bundle row located at the upper end protrude above the top surface of the base part 171. This makes it possible to clean a wide area in the occlusal direction, and to thoroughly clean areas such as the gums on the cheek side that are located farther from the occlusal surface K.

[0172] The arrangement pitch of the bristle bundles 172 in the circumferential direction in adjacent bristle bundle rows in the meshing direction is preferably offset by, for example, half a pitch. In this case, by arranging the bristle bundles 172 in a staggered manner when viewed in the direction facing the brush surface 171a, the gaps between the bristle bundles 172 can be reduced, improving the fit to the cheek-side tooth surface and cleaning performance.

[0173] When viewed from above, the bristle bundles 172 extend radially inward from the brush surface 171a. As shown in FIG. 21 , the outer upper brush portion 132A constituting the brush unit 130 has a portion where the base portion 171 curves, where the arrangement pitch of the roots of the bristle bundles 172 differs from the arrangement pitch of the tips. Specifically, the arrangement pitch P4 of the tips of the bristle bundles 172 is smaller than the arrangement pitch P3 of the roots. By varying the arrangement pitch between the bristle bundles 172 at the roots and tips, it is possible to adjust the balance between rigidity and flexibility, improving cleaning performance. For example, by reducing the arrangement pitch of the roots of the bristle bundles 172, bristle stiffness can be ensured, while by increasing the arrangement pitch of the tips, bristle penetration into interdental gaps can be ensured, improving cleaning performance. Furthermore, the bristle bundles 172 can be applied to cover all teeth from both the front and back, improving the cleaning experience.

[0174] Although the example shows a configuration in which the arrangement pitch of the bristle bundles 172 in the brush unit 130 is different at the tip and base, for example, the arrangement pitch of the bristle bundles 172 in brush units 130 spaced apart in the circumferential direction (the pitch of the bristle bundles in the first brush unit and the bristle bundles in the second brush unit) may be different at the tip and base. Also, by adjusting the planting angle of the bristle bundles 172 and adjusting the arrangement pitch at the tip and base while suppressing interference between the bristle bundles 172 of brush units 130 spaced apart in the circumferential direction (particularly the curved portion of the outer brush unit 132), the cleaning feel and cleaning performance can be improved.

[0175] Figure 21 illustrates a configuration in which the arrangement pitch P4 of the bristle tip portions is smaller than the arrangement pitch P3 of the base portion at the point where the base portion 171 curves, but regardless of whether the base portion 171 has a curved shape or not, by arbitrarily adjusting the bristle planting angle in the depth direction, it is possible to create a difference in the pitch between the base portion and the tip portion of the bristle bundles 172, thereby achieving the above-mentioned effect and preventing interference between the bristles in the brush portion 130.

[0176] Returning to Figure 18, the outer upper brush part 132B is located to the right of the outer upper brush part 132A in the circumferential direction. The outer upper brush part 132C is located to the right of the outer upper brush part 132B in the circumferential direction. The circumferential end of the outer upper brush part 132C on the side closer to the outer upper brush part 132B (the +θ side) has a shape that is an extension of the curved shape of the outer upper brush part 132A. The -θ side of the outer upper brush part 132C has a linear shape that is tangent to the curved shape. The outer upper brush part 132C is mainly positioned opposite the cheek-side tooth surfaces of multiple molars (premolars, molars) on the maxillary side.

[0177] When viewed from above, the outer upper brush part 132B has a linear shape connecting the -θ side end of the outer upper brush part 132A and the +θ side end of the outer upper brush part 132C. The outer upper brush part 132B is formed in a linear shape because its circumferential dimension is short and there is little advantage to curving it.

[0178] 19 , the base portion 171 of the outer lower brush portion 132F is detachably fitted from the inside into a fitting recess 162F (details of which will be described later) in the outer support body 152. The base portion 171 is coupled to the outer support body 152 by fitting its upper and lower surfaces, which form a connecting portion 173, into the fitting recess 162F. The detachable fitting of the base portion 171 into the fitting recess 162F makes the outer lower brush portion 132F replaceable with respect to the outer support body 152.

[0179] The lower outer brush part 132F is vertically symmetrical in the meshing direction relative to the upper outer brush part 132A, with the meshing surface K as the center. The bristle bundles 172 in the lower outer brush part 132F extend inward from the brush surface 171a. The brush surface 171a is inclined outward as it extends downward. The bristle implantation holes 171b extend at an angle relative to the meshing surface K. The bristle implantation holes 171b are inclined downward as they extend inward.

[0180] The bristle bundles 172 planted in the bristle planting holes 171b of the outer lower brush part 132F extend at an angle downward as they move inward. Therefore, in a bristle bundle row in which multiple bristle bundles 172 are arranged in the circumferential direction, the bristle tips are inclined toward the lower end of the base part 171 relative to the roots. Of the bristle bundle rows aligned in the interdigital direction, the bristle tips of the bristle bundles 172 in the bristle bundle row located at the lower end protrude below the underside of the base part 171. This makes it possible to clean a wide area in the interdigital direction, and to thoroughly clean gums and other areas far from the interdigital surface K.

[0181] The method of tying the tufts 172 is the same as the method of tying the tufts 142 .

[0182] The bristle-tip distance, which is the shortest distance between the bristle bundles 142 of the inner brush part 131 and the bristle bundles 172 of the outer brush part 132, varies depending on the circumferential position. The outer brush part 132 and the inner brush part 131 each have a central region including the circumferential center of the support 150 and end regions located at the circumferential ends of the support 150. An intermediate region is provided between the central region and the end regions. The central region is a region that primarily faces the front teeth. The end regions are a region that primarily faces the premolars to molars. The intermediate region is a region that primarily faces the canines to premolars. As shown in FIG. 17 , in the outer brush part 132, the central region is designated as the first region A1, the intermediate region is designated as the second region A2, and the end regions are designated as the third region A3. In the inner brush part 131, the central region is designated as the first region B1, the intermediate region is designated as the second region B2, and the end regions are designated as the third region B3.

[0183] The distance between the bristle tips between the first region A1 and the first region B1 is D1, the distance between the bristle tips between the second region A2 and the second region B2 is D2, and the distance between the bristle tips between the third region A3 and the third region B3 is D3. The distance between the bristle tips D1 is the distance between the bristle bundle 172 with the shortest bristle length of the outer brush part 132 in the first region A1 and the bristle bundle 142 with the shortest bristle length of the inner brush part 131 in the first region B1. The distance between the bristle tips D2 is the distance between the bristle bundle 172 with the shortest bristle length of the outer brush part 132 in the second region A2 and the bristle bundle 142 with the shortest bristle length of the inner brush part 131 in the second region B2. The distance between the bristle tips D3 is the distance between the bristle bundle with the shortest bristle length of the outer brush part 132 in the third region A3 and the bristle bundle 142 with the shortest bristle length of the inner brush part 131 in the third region B3. The shortest bristle distance is the distance between the shortest bristles in the depth direction between the inner and outer bristles on the same plane perpendicular to the circumferential direction (i.e., a plane extending in the depth direction) relative to the inner support 151. This bristle distance is measured when viewed in the interdigital direction (e.g., from above). In other words, the bristles measured as the bristle distance may be located at different positions in the interdigital direction. If the bristles with the shortest bristles in the depth direction are not on the same plane perpendicular to the circumferential direction, the plane is considered to be a virtual space with a thickness of ±0.5 mm in the circumferential direction, and the bristles are considered to be on the same plane if they fit within this virtual space. In other words, the bristles with the shortest bristles in the depth direction are considered to be on the same plane if the circumferential separation is within 1.0 mm. By arranging the brush unit 130 in a number corresponding to the area in the oral cavity, specifications suitable for cleaning each area (improved bristle stiffness, setting a step profile to match the tooth arch shape) can be achieved, allowing each area in the oral cavity to be thoroughly cleaned. The distances D1 and D3 between the bristle tips satisfy the relationship D3 > D1. In other words, the distance D3 between the bristle tips in the area facing mainly the back teeth, including the premolars and molars, is greater than the distance D1 between the bristle tips in the area facing mainly the front teeth. By setting the distance between the bristle tips to suit the size of the teeth in each area, such as the front teeth being thin and therefore having a small distance between them, and the back teeth being thick and therefore having a large distance between them, it is possible to improve the fit to the dentition and cleaning power. It is preferable that the distances D1, D2, and D3 between the bristle tips satisfy the relationship D3 > D2 > D1.That is, the gap in the depth direction between the outer brush part 132 and the inner brush part 131 is larger in the second areas A2, B2 than in the first areas A1, B1, and larger in the third areas A3, B3 than in the second areas A2, B2.

[0184] When the length from the center to the end in the circumferential direction of the support 150 is taken as 100%, the region from the center to 40% in the circumferential direction is taken as the first region A1, B1, the region from 40% to 65% is taken as the second region A2, B2, and the region from 65% to 100% is taken as the third region A3, B3, it is preferable that the distances D1, D2, D3 between the bristle tips satisfy the relationship D1<D2<D3.

[0185] Furthermore, when the mouthpiece 120 is electrically driven, the vibration is caused by the rotational motion of the shaft 114, and the amplitude is large in the third regions A3 and B3, which have a large radius of rotation around the shaft 114. Depending on this vibration characteristic, it is possible to provide an optimal space (range of motion) between the bristles, improving the cleaning feel and cleaning performance.

[0186] The distance D1 between the bristle ends is preferably 0.5 to 4.0 mm, the distance D2 between the bristle ends is preferably 2.0 to 9.0 mm, and the distance D3 between the bristle ends is preferably 4.0 to 12.0 mm.

[0187] The length in the meshing direction of the base portion 171 of the outer brush part 132 located in the first region A1 is defined as WA1. The length in the meshing direction of the base portion 171 of the outer brush part 132 located in the second region A2 is defined as WA2. The length in the meshing direction of the base portion 171 of the outer brush part 132 located in the third region A3 is defined as WA3. The length in the meshing direction of the base portion 141 of the inner brush part 131 located in the first region B1 is defined as WB1. The length in the meshing direction of the base portion 141 of the inner brush part 131 located in the second region B2 is defined as WB2. The length in the meshing direction of the base portion 141 of the inner brush part 131 located in the third region B3 is defined as WB3. It is preferable that the relationships WA1 > WA2 > WA3 and WB1 > WB2 > WB3 are satisfied, respectively.

[0188] Because the surface area of ​​the front teeth is larger in the occlusal direction than that of the back teeth, it is necessary to increase the length WA1 of the first region A1 facing the front teeth and the length WB1 of the first region B1. Furthermore, because back teeth are thicker in the depth direction than the front teeth and the space in the oral cavity around the back teeth is limited, reducing the occlusal direction length WA3 of the base portion 171 and the occlusal direction length WB3 of the base portion 141 can reduce the feeling of pressure in the oral cavity and the risk of reflex vomiting. This improves the cleaning feel and cleaning performance.

[0189] The relationship between the lengths of the outer brush portion 132 and the inner brush portion 131 in the meshing direction is preferably WA1 > WB1, WA2 > WB2, and WA3 > WB3. The length WA1 is preferably 5 to 10 mm. The length WA2 is preferably 4 to 9 mm. The length WA3 is preferably 2 to 9 mm. The length WB1 is preferably 4 to 9 mm. The length WB2 is preferably 3 to 8 mm. The length WB3 is preferably 2 to 8 mm.

[0190] The length in the occlusal direction of base portion 141 and base portion 171 is preferably 25 mm or less. By setting the length in the occlusal direction to 25 mm or less, outer brush portion 132 and inner brush portion 131 do not become too large, and discomfort in the oral cavity can be reduced. The total length in the occlusal direction of base portion 141 and base portion 171 for the upper and lower jaws is preferably 50 mm or less, and when separated into the upper and lower jaws, the upper jaw portion (mandibular portion) is preferably 25 mm or less.

[0191] When the bristle bundles 142, 172 are positioned away from the mating surface K to improve the cleaning feel, if the brush surfaces 141a, 171a are arranged perpendicular to the depth direction and the bristle holes 141b, 171b are arranged to extend in the normal direction of the brush surfaces 141a, 171a, the brush surfaces 141a, 171a become longer in the mating direction, and the bases 141, 171 become larger, reducing usability. On the other hand, if the brush surfaces 141a, 171a are arranged perpendicular to the depth direction and the bristle holes 141b, 171b are inclined with respect to the normal direction of the brush surfaces 141a, 171a, the bristle tips of the bristle bundles 142, 172 are positioned away from the mating surface K according to the inclination angle of the bristle holes 141b, 171b. In this case, the maximum dimension of the tufting holes 141b, 171b on the brush surfaces 141a, 171a is greater than the diameter of the tufting holes 141b, 171b. For example, if the diameter of the tufting holes 141b, 171b is d and the inclination angle of the tufting holes 141b, 171b with respect to the normal direction of the brush surfaces 141a, 171a is θ1, the maximum dimension S of the tufting holes 141b, 171b on the brush surfaces 141a, 171a is a value expressed as d / cos(θ1), which is greater than the diameter d. In the base portions 141, 171 in which the bristle implantation holes 141b, 171b are formed, a minimum thickness is specified to ensure strength, so if the bristle implantation holes 141b, 171b are inclined relative to the normal direction of the brush surfaces 141a, 171a, the maximum dimension S increases, and the dimension of the base portions 141, 171 in the meshing direction becomes longer.

[0192] In this embodiment, the normal direction of the brush surfaces 141a, 171a is inclined relative to the depth direction, and further, the bristle holes 141b, 171b are inclined relative to the normal direction of the brush surfaces 141a, 171a, so that the inclination angle θ1 is reduced, thereby reducing the maximum dimension S. As a result, compared to when the brush surfaces 141a, 171a are perpendicular to the depth direction, it is possible to position the bristle tips of the bristle bundles 142, 172 away from the meshing surface K while suppressing the dimension of the base portions 141, 171 in the meshing direction.

[0193] The bristles constituting the bristle bundles 142, 172 may be a mixture of one or more bristle types. Also, two or more bristle types may be used within the same brush unit 130 or within the same area. By using a bristle type suited to brushing each area, cleaning performance can be improved. Furthermore, since the brush unit 130 is detachable, it is possible to replace the brush unit 130 with one having a bristle type suited to the user's preferences, thereby improving the cleaning experience and cleaning performance.

[0194] The bristle diameter in the first areas A1 and B1 is preferably 3 to 6 mils. The bristle diameter in the second areas A2 and B2 is preferably 3 to 5 mils. The bristle diameter in the third areas A3 and B3 is preferably 4 to 8 mils. By using a bristle diameter suitable for brushing each area, cleaning performance can be improved. Furthermore, cleaning performance can be improved by designing the brush part 130 to the user's preferred hardness.

[0195] The number of bristles is planted so that the first region A1 > the second region A2 > the third region A3. The number of bristles is planted so that the first region B1 > the second region B2 > the third region B3. In the first region A1 and the first region B1, which have relatively large tooth surface areas, planting many bristles results in a structure in which the bristles contact the entire tooth surface, improving the cleaning feel and cleaning performance. Furthermore, planting a relatively small number of bristles in the third region A3 and the third region B3 reduces the feeling of pressure caused by the bristles contacting the gums and oral mucosa in the narrow oral cavity on the molar side, and also suppresses reflex vomiting, improving the cleaning feel.

[0196] The number of bristles in the first region A1 is preferably 150 to 500. The number of bristles in the second region A2 is preferably 150 to 500. The number of bristles in the third region A3 is preferably 70 to 250. The number of bristles in the first region B1 is preferably 100 to 500. The number of bristles in the second region B2 is preferably 100 to 500. The number of bristles in the third region B3 is preferably 50 to 250. If the number of bristles in each region is less than the above-mentioned preferred range, the brush unit 130 will feel sparse, and the cleaning experience will be reduced. Furthermore, if the number of bristles is more than the above-mentioned preferred range, the brush unit 130 will be overcrowded, preventing the bristle bundles 142, 172 from bending properly when the mouthpiece unit 120 is moved, and preventing smooth movement of the mouthpiece unit 120. By setting the number of bristles within the above-mentioned preferred range, the bristle bundles 142, 172 can bend appropriately, improving the cleaning experience. Note that the above-mentioned number of bristles is merely an example, and may exceed the upper limit. For example, when using large holes with non-flat wires, a range of 4,000 to 200,000 bristles is preferable.

[0197] The bristles with the longest length planted in the third region A3 are preferably longer, partially or entirely, than the bristles with the longest length planted in the first region A1 and the second region A2. The bristles with the longest length planted in the third region B3 are preferably longer, partially or entirely, than the bristles with the longest length planted in the first region B1 and the second region B2. By satisfying the above relationship, it is possible to ensure the ability to penetrate and clean molars with deep interdental spaces, and it is also possible to change the period of the arrangement profile according to tooth size, thereby improving the fit.

[0198] In the first region A1 and the first region B1, bristles with a maximum bristles length of 2 to 7 mm are planted at a single bristles length or at multiple bristles lengths. In the third region A3, bristles with a maximum bristles length of 3 to 8 mm are planted at a single bristles length or at multiple bristles lengths. The difference in bristles length between the bristles with the longest bristles planted in the third region A3 and the bristles with the shortest bristles planted in the first region A1 and the second region A2 is preferably 1 to 6 mm. Furthermore, at least in the third region A3 and the third region B3, a difference in bristles length is provided within the region. The difference in bristles length is preferably 1 to 5 mm.

[0199] Figures 22 and 23 are external perspective views of the support body 150 in a fifth embodiment of the mouthpiece portion 120. Figure 22 is a perspective view of the support body 150 as seen from the inside in the depth direction. Figure 23 is a cross-sectional view taken along line E-E in Figure 22, and is a perspective cross-sectional view of the support body 150 as seen from the outside in the depth direction. The shaft 114 is not shown in Figure 22.

[0200] The support body 150 supports the brush unit 130 in the circumferential direction. As shown in Figures 22 and 23 , the support body 150 has an inner support body 151, an outer support body 152, and a connecting portion 153.

[0201] The inner support body 151 is formed in a U-shape when viewed from above. The inner support body 151 has an upper wall portion 154 located at the upper end and extending in the circumferential direction, a lower wall portion 155 located at the lower end and extending in the circumferential direction, an intermediate wall portion 156 located between the upper wall portion 154 and the lower wall portion 155 in the meshing direction and extending in the circumferential direction, and connecting wall portions 157, 158, and 159 extending in the meshing direction and connecting the upper wall portion 154 and the lower wall portion 155 via the intermediate wall portion 156. The upper wall portion 154, the lower wall portion 155, and the intermediate wall portion 156 are arranged over the entire circumferential direction. The connecting wall portions 157 and 158 are arranged at a distance in the circumferential direction. The connecting wall portions 159 are formed at both ends in the circumferential direction.

[0202] The inner support body 151 has mating recesses 161A, 161B, and 161C located on the upper side and mating recesses 161D, 161E, and 161F located on the lower side. The mating recesses 161A, 161B, and 161C and the mating recesses 161D, 161E, and 161F are formed by being recessed inward from the surface of the inner support body 151 facing outward in the depth direction.

[0203] In the inner support body 151, the fitting recesses 161B and 161C are line-symmetrical in the left-right direction, and therefore the description of the fitting recess 161C may be omitted or simplified. Also, the fitting recesses 161D, 161E, and 161F are line-symmetrical in the meshing direction with the fitting recesses 161A, 161B, and 161C, respectively, and therefore the description of the fitting recesses 161D, 161E, and 161F may be omitted or simplified.

[0204] 19, the base portion 141 of the inner upper brush part 131A is removably fitted into the fitting recess 161A from the outside. In the fitting recess 161A, the upper wall portion 154 and the intermediate wall portion 156 are fitted into the connecting portion 143 of the inner upper brush part 131A in the meshing direction, and the connecting wall portions 157 and 158 are fitted into both ends of the base portion 141 in the circumferential direction, thereby removably joining the inner upper brush part 131A.

[0205] The base portion 141 of the inner upper brush part 131B is removably fitted into the fitting recess 161B from the outside. In the fitting recess 161B, the upper wall portion 154 and the intermediate wall portion 156 are fitted into the connecting portion 143 of the inner upper brush part 131B in the meshing direction, and the connecting wall portions 157 and 159 are fitted into both ends of the base portion 141 in the circumferential direction, thereby removably joining the inner upper brush part 131B.

[0206] Base portion 141 of lower inner brush portion 131D is removably fitted into fitting recess 161D from the outside. In fitting recess 161D, lower wall portion 155 and intermediate wall portion 156 are fitted into connecting portion 143 of lower inner brush portion 131D in the meshing direction, and connecting wall portions 157 and 158 are fitted into both ends of base portion 141 in the circumferential direction, thereby removably joining lower inner brush portion 131D.

[0207] The base portion 141 of the inner upper brush part 131C is removably fitted into the fitting recess 161C from the outside. The base portion 141 of the inner lower brush part 131E is removably fitted into the fitting recess 161E from the outside. The base portion 141 of the inner lower brush part 131F is removably fitted into the fitting recess 161F from the outside.

[0208] The outer support body 152 is U-shaped when viewed from above. The outer support body 152 has an upper wall portion 164 located at its upper end and extending in the circumferential direction, a lower wall portion 165 located at its lower end and extending in the circumferential direction, an intermediate wall portion 166 located between the upper wall portion 164 and the lower wall portion 165 in the meshing direction and extending in the circumferential direction, and connecting wall portions 167, 168, 169, 170, and 152A extending in the meshing direction and connecting the upper wall portion 164 and the lower wall portion 165 via the intermediate wall portion 166. The upper wall portion 164, the lower wall portion 165, and the intermediate wall portion 166 are arranged over the entire circumferential direction. The connecting wall portions 167 and 168 are spaced apart in the circumferential direction. The connecting wall portions 169 and 170 are arranged circumferentially outward of the connecting wall portions 167 and 168, respectively. The connecting wall portions 152A are formed on both ends in the circumferential direction. The intermediate wall portion 166 is positioned at the same position as the intermediate wall portion 156 in the meshing direction.

[0209] The outer support body 152 has mating recesses 162A, 162B, 162C, 162D, and 162E located on the upper side and mating recesses 162F, 162G, 162H, 162J, and 162K located on the lower side. The mating recesses 162A, 162B, 162C, 162D, and 162E and the mating recesses 162F, 162G, 162H, 162J, and 162K are formed by being recessed outward from the surface of the outer support body 152 facing inward in the depth direction.

[0210] In the outer supporting body 152, the fitting recesses 162B and 162D are line-symmetric in the left-right direction, and the fitting recesses 162C and 162E are line-symmetric in the left-right direction, so descriptions of the fitting recesses 162D and 162E may be omitted or simplified. Also, the fitting recesses 162F, 162G, 162H, 162J, and 162K are line-symmetric in the meshing direction with the fitting recesses 162A, 162B, 162C, 162D, and 162E, respectively, so descriptions of the fitting recesses 162F, 162G, 162H, 162J, and 162K may be omitted or simplified.

[0211] 19, the base portion 171 of the outer upper brush part 132A is detachably fitted into the fitting recess 162A from the inside. In the fitting recess 162A, the upper wall portion 164 and the intermediate wall portion 166 are fitted into the connecting portion 173 of the outer upper brush part 132A in the meshing direction, and the connecting wall portions 167 and 168 are fitted into both ends of the base portion 171 in the circumferential direction, thereby detachably joining the outer upper brush part 132A.

[0212] The base portion 171 of the outer upper brush part 132B is detachably fitted into the fitting recess 162B from the inside. In the fitting recess 162B, the upper wall portion 164 and the intermediate wall portion 166 are fitted into the connecting portion 173 of the outer upper brush part 132B in the meshing direction, and the connecting wall portions 167 and 169 are fitted into both ends of the base portion 171 in the circumferential direction, thereby detachably joining the outer upper brush part 132B.

[0213] The base portion 171 of the outer upper brush part 132C is detachably fitted into the fitting recess 162C from the inside. In the fitting recess 162C, the upper wall portion 164 and the intermediate wall portion 166 are fitted into the connecting portion 173 of the outer upper brush part 132C in the meshing direction, and the connecting wall portion 169 and the connecting wall portion 152A are fitted into both ends of the base portion 171 in the circumferential direction, thereby detachably joining the outer upper brush part 132C.

[0214] The base portion 171 of the outer lower brush part 132F is detachably fitted into the fitting recess 162F from the inside. In the fitting recess 162F, the lower wall portion 165 and the intermediate wall portion 166 are fitted into the connecting portion 173 of the outer lower brush part 132F in the meshing direction, and the connecting wall portions 167 and 168 are fitted into both ends of the base portion 171 in the circumferential direction, thereby detachably joining the outer lower brush part 132F.

[0215] The base portion 171 of the outer upper brush part 132D is detachably fitted into the fitting recess 162D from the inside. The base portion 171 of the outer upper brush part 132E is detachably fitted into the fitting recess 162E from the inside. The base portion 171 of the outer lower brush part 132G is detachably fitted into the fitting recess 162G from the inside. The base portion 171 of the outer lower brush part 132H is detachably fitted into the fitting recess 162H from the inside. The base portion 171 of the outer lower brush part 132J is detachably fitted into the fitting recess 162J from the inside. The base portion 171 of the outer lower brush part 132K is detachably fitted into the fitting recess 162K from the inside.

[0216] The connecting portion 153 connects the inner support body 151 and the outer support body 152 in the depth direction. The connecting portion 153 connects the inner support body 151 and the outer support body 152 at both ends in the circumferential direction. The connecting portion 153 of this embodiment configures the support body 150 as a molded body integrally molded with the inner support body 151 and the outer support body 152. Note that the connecting portion 153 may be manufactured separately from the inner support body 151 and the outer support body 152 without being integrally molded with them, and may be configured to be joined to the support body 150 in the same way as the brush portion 130, or may be configured to be fixed to the support body 150 with an adhesive or the like.

[0217] The connecting portion 153 has a connecting plate 153A and a bristle bundle 153B. The connecting plate 153A is plate-shaped and perpendicular to the meshing direction, extending to the lower end in the circumferential direction. The inner end of the connecting plate 153A is connected to the intermediate wall portion 156 of the inner support body 151. The outer end of the connecting plate 153A is connected to the intermediate wall portion 166 of the outer support body 152.

[0218] The bristle bundles 153B extend in the occlusal direction from the upper and lower surfaces of the connecting plate 153A. The bristle bundles 153B are arranged, for example, in positions facing the molars. Because the bristle bundles 153B are arranged in positions facing the molars and protrude upward and downward, they can effectively clean the occlusal surfaces of the molars, which are difficult for the brush unit 130 to reach.

[0219] As described above, the support body 150 is a molded body in which the inner support body 151, the outer support body 152, and the connecting portion 153 are integrally molded. Because the support body 150 is a molded body molded as a separate member from the brush portion 130, the support body 150 is not restricted by the brush portion 130 and can be made to expand appropriately, neither too tight nor too loose. This improves the fit of the support body 150 to the dentition.

[0220] The support 150 is molded from a different material than the base portions 141, 171 of the brush unit 130. The support 150 is formed from a resin with a lower hardness than the base portions 141, 171. Therefore, the base portions 141, 171 are at least partially covered by the support 150, which is formed from a different material. By covering the base portions 141, 171 at least partially with the support 150, which is softer than the base portions 141, 171, the risk of damaging the gums or oral mucosa due to contact of the mouthpiece unit 120 with the oral mucosa can be reduced, improving the cleaning experience. Furthermore, because the brush unit 130, on which the bristle bundles 142, 172 are implanted, is connected to the support 150, it is not necessary to implant the bristle bundles directly into the support 150, thereby improving manufacturability and cleaning performance.

[0221] The difference in hardness between the material constituting the base portions 141, 171 and the material constituting the support 150 is preferably a flexural modulus of 200 MPa or more, more preferably a flexural modulus of 500 MPa or more. The difference in hardness between the material constituting the base portions 141, 171 and the material constituting the support 150 is preferably a flexural modulus of 2800 MPa or less, more preferably a flexural modulus of 1500 MPa or less. The upper and lower limit values ​​of the material constituting the base portions 141, 171 and the material constituting the support 150 can be arbitrarily combined. If the hardness difference is below the above-mentioned lower limit, there is a risk that hard materials may break when fitted together, and soft materials may easily come loose, which may hinder proper fitting. Furthermore, the base portions 141, 171 need to be relatively hard to ensure implant strength, while the support 150 needs to be relatively flexible to improve fit to the dentition when the mouthpiece portion 120 is moved. If the hardness difference falls below the lower limit, one of the above roles will not be able to be fulfilled. If the hardness difference of the materials is within the above range, the base parts 141, 171 and the support body 150, which are made of different materials, can move with a moderate sense of interlocking. In this embodiment, by setting the hardness difference of the materials within the above range, even though they are different components, they can move with a moderate sense of interlocking, improving the cleaning experience.

[0222] The hardness of the material constituting the base portions 141, 171 is preferably a flexural modulus of 800 MPa or more and 3000 MPa or less. If the hardness of the material constituting the base portions 141, 171 is less than 800 MPa, cracks are likely to occur during implantation, making implanting the bristle bundles 142, 172 difficult. Furthermore, sufficient implant strength cannot be ensured when moving in conjunction with the support 150, and vibration transmission during electrical use may also be reduced. If the hardness of the material constituting the base portions 141, 171 exceeds 3000 MPa, there is a risk of injury to the oral cavity. Furthermore, there is a risk of damaging the support 150 when moving the mouthpiece portion 120 or fitting it into the support 150. By setting the hardness of the material constituting the base portions 141, 171 to a flexural modulus of elasticity of 800 MPa or more and a flexural modulus of elasticity of 3000 MPa or less, it is possible to reduce the possibility of damaging the oral cavity while ensuring sufficient hair implant strength to move in conjunction with the support body 150.

[0223] The hardness of the material constituting the support 150 is preferably 50 MPa or more and 1000 MPa or less. If the hardness of the material constituting the support 150 is less than 50 MPa, it may not be able to adequately support the base portions 141, 171. If the hardness of the material constituting the support 150 exceeds 1000 MPa, it may not be comfortable when it comes into contact with the buccal mucosa and tongue. It may also cause a strong feeling of pressure in the oral cavity, which may lead to reflex vomiting. Furthermore, when the mouthpiece portion 120 is moved, the shape may not follow, and it may not be possible to ensure a good fit to the dentition. By setting the hardness of the material constituting the support 150 to 50 MPa or more and 100 MPa or less, it is possible to adequately support the base portions 141, 171 and ensure a comfortable softness when it comes into contact with the buccal mucosa and tongue.

[0224] The separation area of ​​the contours of the inner support 151 and outer support 152 constituting the support 150 is preferably 20% or more, and more preferably 30% or more. The separation area of ​​the contours of the inner support 151 and outer support 152 constituting the support 150 is preferably 70% or less, and more preferably 60% or less. The upper and lower limits of the separation area of ​​the contours of the inner support 151 and outer support 152 constituting the support 150 can be arbitrarily combined. If the separation area is within the above range, the shape of the support 150 can be stabilized, and it can fit firmly to the dentition and ensure cleaning power. Furthermore, since the connection between the inner support 151 and outer support 152 is only partial, the area available for bristles to be implanted can be increased, improving cleaning power.

[0225] The part where the inner support 151 and the outer support 152 are connected is preferably the circumferential center or the occlusal surface of the molars. This allows vibration to be easily transmitted when the mouthpiece 120 is electrically operated, improving cleaning power. Also, when the occlusal surface of the molars is connected, the occlusion of the molars can be cleaned.

[0226] A manufacturing method of toothbrush 101 having the above-described configuration includes toothbrush 101 having gripping portion 110 and mouthpiece portion 120 connected to gripping portion 110, mouthpiece portion 120 having brush portion 130 having base portions 141, 171 on which bristles 142, 172 are provided, and support 150 molded from a material different from base portions 141, 171, covering at least a portion of base portions 141, 171, and supporting brush portion 130 in a circumferential direction centered on an axis extending in the meshing direction, the manufacturing method includes preparing brush portion 130, preparing support 150, and joining brush portion 130 to support 150.

[0227] Preparing the brush unit 130 includes preparing inner upper brush units 131A, 131B, and 131C and inner lower brush units 131D, 131E, and 131F, which constitute the inner brush unit 131 having bristle bundles 142 attached to a base unit 141. Preparing the brush unit 130 also includes preparing outer upper brush units 132A, 132B, 132C, 132D, and 132E and outer lower brush units 132F, 132G, 132H, 132J, and 132K, which constitute the outer brush unit 132 having bristle bundles 172 attached to a base unit 171. Preparing the brush unit 130 also includes implanting the bristle bundles 142 into the bristle implantation holes 141b of the base unit 141 and implanting the bristle bundles 172 into the bristle implantation holes 171b of the base unit 171.

[0228] Preparing the support 150 includes integrally molding the inner support 151, the outer support 152, and the connecting portion 153 by injection molding or the like. If the mouthpiece portion 120 is electric and the shaft 114 is insert-molded, preparing the support 150 includes molding the inner support 151, the outer support 152, the connecting portion 153, and the shaft 114 by injection molding or the like. If the mouthpiece portion 120 is electric and the shaft 114 is fixed after the inner support 151, the outer support 152, and the connecting portion 153 are integrally molded, preparing the support 150 includes integrally molding the inner support 151, the outer support 152, and the connecting portion 153 by injection molding or the like, and fixing the shaft 114.

[0229] Joining brush unit 130 to support body 150 includes fitting and joining base units 141, 171 of each prepared brush unit 130 into fitting recesses 161A, 161B, 161C and fitting recesses 161D, 161E, 161F of inner support body 151 of prepared support body 150, and fitting and joining base units 141, 171 of each prepared brush unit 130 into fitting recesses 162A, 162B, 162C, 162D, 162E and fitting recesses 162F, 162G, 162H, 162J, 162K of outer support body 152. By joining and supporting brush unit 130 to support body 150, mouthpiece unit 120 is produced in which brush units 130 are arranged in a U-shape along the circumferential direction, as shown in FIG.

[0230] As described above, in toothbrush 101 of this embodiment, brush section 130 and support 150, each having bristle bundles 142, 172 made of different materials, are joined to form mouthpiece section 120, so each section can be given an optimal shape, material, and other specifications without being restricted by the other. Therefore, toothbrush 101 of this embodiment can improve the cleaning performance of each area in the oral cavity and improve the cleaning experience due to the support 150's close fit to the dentition.

[0231] While the preferred embodiments of the toothbrush and toothbrush manufacturing method according to the second embodiment have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0232] For example, in the above embodiment, the inner support 151 and the outer support 152 are configured to be continuous in the circumferential direction, but the present invention is not limited to this configuration, and may alternatively be configured, for example, so that the locations supporting the brush unit 130 are arranged intermittently in the circumferential direction. When this configuration is adopted, for example, the connecting unit 153 may be arranged over the entire circumferential direction, the inner support 151 may be arranged intermittently inside the connecting unit 153, and the outer support 152 may be arranged intermittently outside the connecting unit 153. Furthermore, instead of being configured so that the mouthpiece unit 120 is provided over the entire circumferential direction, the mouthpiece unit 120 may alternatively be provided in only one of the left and right regions, and the connecting unit 153 may also be provided only in that region.

[0233] In the above embodiment, the connecting portion 153 connecting the inner support 151 and the outer support 152 is disposed at the circumferential end, but the present invention is not limited to this configuration. For example, as shown in Fig. 24, the connecting portion 153 may connect the inner support 151 and the outer support 152 at the circumferential center. In Fig. 24, the brush unit 130 and the support 150 are shown simply, and the bristle bundles are not shown.

[0234] Furthermore, similar to the connecting plate 153A described in the above embodiment, a flat protrusion may be provided from at least one of the inner support body 151 and the outer support body 152 toward the other. The protrusion may connect the inner support body 151 and the outer support body 152. By providing the protrusion, the meshing surfaces of the teeth can be rubbed, improving cleaning power. The thickness of the protrusion is preferably 0.5 to 3.0 mm.

[0235] Third Embodiment of Toothbrush A toothbrush and a method for manufacturing the toothbrush according to a third embodiment will now be described with reference to FIGS.

[0236] Figure 25 is a front view of toothbrush 201 of the third embodiment. As shown in Figure 25, toothbrush 201 is a mouthpiece-type toothbrush and has a grip portion 210 and a connector 220. Hereinafter, connector 220 will be referred to as mouthpiece portion 220. Vibrations are imparted to mouthpiece portion 220 via grip portion 210. A shaft 214 protrudes from grip portion 210 and is connected to mouthpiece portion 220. Note that a configuration in which shaft 214 protruding from mouthpiece portion 220 is connected to grip portion 210 may also be used. Vibrations are imparted to mouthpiece portion 220 from grip portion 210 via shaft 214.

[0237] The present invention is applicable to any of a configuration in which a brushing action is manually applied from grip portion 210 to mouthpiece portion 220 in up-down, left-right, front-rear, or a combination thereof, a configuration in which vibration is manually applied, and a configuration in which vibration is electrically applied from grip portion 210 to mouthpiece portion 220. In this embodiment, an electric drive unit is provided in grip portion 210, and vibrations generated by driving the electric drive unit are applied to mouthpiece portion 220.

[0238] The electric drive unit includes a power supply 211, a vibration element 212, and a control unit 213. The control unit 213 drives the vibration element 212 using power from the power supply 211. The power supply 211 is configured, for example, with a rechargeable battery or a cell. The vibration element 212 is configured, for example, with a piezoelectric element, an electromagnetic acoustic transducer, an unbalanced motor, or the like. The vibration generated by the vibration element 212 is a vibration that rotates around an axis extending in the depth direction, and repeatedly reverses its rotational direction at a predetermined rotation angle. A shaft 214 connected to the electric drive unit in the grip 210 vibrates by repeatedly reversing its rotational direction. When the vibration element 212 drives the shaft 214, the mouthpiece 220 vibrates by repeatedly reversing its rotational direction.

[0239] [Sixth embodiment of mouthpiece unit 220] The mouthpiece unit 220 has a first brush body 230, a second brush body 260, and a connecting unit 280. The first brush body 230 is located inside the grip unit 210 in the depth direction. The second brush body 260 is located between the grip unit 210 and the first brush body 230 in the depth direction, and is spaced apart from the first brush body 230. The second brush body 260 is located with a gap S between it and the first brush body 230.

[0240] When the mouthpiece part 220 is attached to the oral cavity, the first brush body 230 is located on the tongue side, which is inside the row of teeth, and the second brush body 260 is located on the cheek side, which is outside the row of teeth.

[0241] The first brush body 230 has a first support 231 and a first brush portion 241. The first support 231 supports the base end side of the first brush portion 241. When viewed from above, the first support 231 is formed in a U-shape (horseshoe shape) along the circumferential direction centered on the axis J. The first support 231 is open to the inside.

[0242] The second brush body 260 has a second support 261 and a second brush portion 271. The second support 261 supports the base end side of the second brush portion 271. When viewed from above, the second support 261 is formed in a U-shape (horseshoe shape) along the circumferential direction centered on the axis J. The second support 261 is open to the inside.

[0243] The range in which the first brush body 230 and the second brush body 260 face the tooth row is not limited to the entire tooth row, but may be a configuration in which they face only a portion of the front teeth (central incisors, lateral incisors), canines, and molars (first premolars, second premolars, first molars, second molars).

[0244] Figure 26 is an external perspective view of the mouthpiece portion 220 as seen from the inside in the depth direction. Figure 27 is a cross-sectional view taken along the line B-B in Figure 26. As shown in Figures 26 and 27, the dimension of the first support 231 in the interlocking direction is largest on the outside in the depth direction and gradually decreases toward the inside. The upper end of the first support 231 is located at the top on the outside in the depth direction and gradually slopes downward toward the inside. The lower end of the first support 231 is located at the bottom on the outside in the depth direction and gradually slopes upward toward the inside.

[0245] The dimension of the second support 261 in the meshing direction is largest on the outside in the depth direction and gradually decreases toward the inside. The upper end of the second support 261 is located at the top on the outside in the depth direction and gradually slopes downward toward the inside. The lower end of the second support 261 is located at the bottom on the outside in the depth direction and gradually slopes upward toward the inside.

[0246] The maximum dimension in the interlocking direction of the second support 261 at the outer side in the depth direction is larger than the maximum dimension in the interlocking direction of the first support 231 at the outer side in the depth direction. The minimum dimension in the interlocking direction of the second support 261 at the inner side in the depth direction is larger than the minimum dimension in the interlocking direction of the first support 231 at the inner side in the depth direction. The dimension in the interlocking direction of the second support 261 is larger than the dimension in the interlocking direction of the first support 231 throughout the entire depth direction.

[0247] Figure 28 is a cross-sectional view taken along the line CC in Figure 25. As shown in Figure 28, the first brush portions 241 are provided on the first support 231 at intervals above and below. The first brush portions 241 are provided on the upper and lower end sides of the first support 231. The first brush portions 241 extend outward in the depth direction from the outer brush surface 231a in the depth direction of the first support 231. The brush surface 231a has a portion that is curved in the circumferential direction in a direction that convex outward when viewed from above.

[0248] This embodiment of the toothbrush 201 uses the first brush part 241, which is arranged along the row of teeth and is designed to be moved manually or electrically. Therefore, the curved brush surface 231a allows the first brush part 241 to be aligned along the tongue side of the row of teeth, improving cleaning performance and fit. In addition, it is possible to maximize the installation area of ​​the first brush part 241, which, when electrically operated, contributes to improved vibration efficiency and cleaning power.

[0249] The first brush portion 241 includes first brush portions 241A, 241B, 241C and first brush portions 241D, 241E, 241F. The first brush portions 241A, 241B, 241C and the first brush portions 241D, 241E, 241F extend outward in the depth direction from the brush surface 231a. The first brush portion 241A extends outward from the upper end of the brush surface 231a. The first brush portion 241B extends outward from a position lower than the first brush portion 241A. The first brush portion 241C extends outward from a position lower than the first brush portion 241B. The first brush portion 241D extends outward from the lower end of the brush surface 231a. First brush portion 241E extends outward from a position higher than first brush portion 241D. First brush portion 241F extends outward from a position higher than first brush portion 241E. As shown in Figures 25 and 26 , a plurality of first brush portions 241 including first brush portions 241A, 241B, 241C and first brush portions 241D, 241E, 241F are provided at intervals throughout the entire circumferential direction.

[0250] If the position where the upper and lower teeth mate in the occlusion direction is defined as occlusion surface K, the inclination angle of the first brush part 241 relative to occlusion surface K in a side view parallel to occlusion surface K becomes smaller the closer it is to occlusion surface K and becomes larger the farther it is from occlusion surface K. Specifically, the inclination angle of the first brush parts 241A and 241D, which are closest to the gums and farthest from the occlusion surface K, is larger than the inclination angles of the first brush parts 241B and 241E and the first brush parts 241C and 241F. The inclination angle of the first brush parts 241C and 241F, which are closest to the occlusion surface K, is smaller than the inclination angles of the first brush parts 241A and 241D and the first brush parts 241B and 241E.

[0251] The mouth tends to open slightly when the mouthpiece portion 220 is held in the mouth. Furthermore, the dimension of the tooth surface in the meshing direction is often larger than the arrangement pitch in the meshing direction at the bases of the first brush portions 241A and 241C and the arrangement pitch in the meshing direction at the bases of the first brush portions 241D and 241F. Therefore, if the inclination angles of the first brush portions 241A to 241C and 241D to 241F are the same, it will be difficult for the tips of the first brush portions 241A to 241C and 241D to 241F to cover the entire tooth surface in the meshing direction.

[0252] In this embodiment, the inclination angle gradually increases from first brush portion 241C to first brush portion 241A, and from first brush portion 241F to first brush portion 241D, so that even when the mouth is slightly open, first brush portions 241C and 241F can fit against the tips of the teeth on the tongue side, and first brush portions 241A and 241D can fit against the gums on the tongue side.

[0253] The circumferential arrangement pitches of adjacent first brush portions 241A and 241B, first brush portions 241B and 241C, first brush portions 241D and 241E, and first brush portions 241E and 241F in the meshing direction are offset by, for example, half a pitch. That is, when viewed in the direction facing brush surface 231a, first brush portions 241A, 241B, 241C and first brush portions 241D, 241E, 241F are arranged in a staggered pattern. By arranging first brush portions 241A, 241B, 241C and first brush portions 241D, 241E, 241F in a staggered pattern, the gaps between first brush portions 241 can be reduced, improving fit to the tooth surface and cleaning performance.

[0254] The second brush portions 271 are provided at intervals above and below the second support 261. The second brush portions 271 are provided respectively at the upper and lower ends of the second support 261. The second brush portions 271 extend inward in the depth direction from a brush surface 261a on the inner side in the depth direction of the second support 261. The brush surface 261a has a portion that is curved in the circumferential direction in a direction that convex outward when viewed from above.

[0255] This embodiment is a toothbrush 201 that uses a second brush part 271 that is aligned along the tooth row and is intended to be moved manually or electrically, so the curved brush surface 261 a allows the second brush part 271 to be aligned along the cheek side of the tooth row, improving cleaning performance and fit. It also maximizes the installation area of ​​the second brush part 271, which, when electrically operated, contributes to improved vibration efficiency and cleaning power.

[0256] The second brush portion 271 includes second brush portions 271A, 271B, 271C, and 271D and second brush portions 271E, 271F, 271G, and 271H. Second brush portions 271A, 271B, 271C, and 271D and second brush portions 271E, 271F, 271G, and 271H extend inward in the depth direction from the brush surface 261a. Second brush portion 271A extends outward from the upper end of brush surface 261a. Second brush portion 271B extends inward from a position lower than second brush portion 271A. Second brush portion 271C extends inward from a position lower than second brush portion 271B. Second brush portion 271D extends inward from a position lower than second brush portion 271C.

[0257] Second brush portion 271E extends inward from the lower end of brush surface 261a. Second brush portion 271F extends inward from a position higher than second brush portion 271E. Second brush portion 271G extends inward from a position higher than second brush portion 271F. Second brush portion 271H extends inward from a position higher than second brush portion 271G. As shown in FIGS. 25 and 26 , a plurality of second brush portions 271, including second brush portions 271A, 271B, 271C, 271D and second brush portions 271E, 271F, 271G, 271H, are provided at intervals throughout the entire circumferential direction.

[0258] In a side view parallel to the occlusal surface K, the inclination angle of the second brush part 271 relative to the occlusal surface K decreases the closer it is to the occlusal surface K and increases the farther it is from the occlusal surface K. Specifically, the inclination angles of the second brush parts 271A and 271E, which are closer to the gums and farthest from the occlusal surface K, are greater than the inclination angles of the second brush parts 271B to 271D and 271F to 271H. The inclination angles of the second brush parts 271C, 271D, 271G, and 271H, which are closer to the occlusal surface K, are smaller than the inclination angles of the second brush parts 271A and 271B and the second brush parts 271E and 271F. As an example, the inclination angles of the second brush parts 271C and 271D are the same, and the inclination angles of the second brush parts 271G and 271H are the same. The inclination angle of second brush portion 271D may be smaller than the inclination angle of second brush portion 271C, and the inclination angle of second brush portion 271H may be smaller than the inclination angle of second brush portion 271G.

[0259] The mouth tends to open slightly when the mouthpiece portion 220 is held in the mouth. Furthermore, the dimension of the tooth surface in the meshing direction is often larger than the arrangement pitch in the meshing direction at the base of second brush portion 271A and second brush portion 271D and the arrangement pitch in the meshing direction at the base of second brush portion 271E and second brush portion 271H. Therefore, if the inclination angles of second brush portions 271A to 271D and 271E to 271H are the same, it will be difficult for the tips of second brush portions 271A to 271D and 271E to 271H to cover the entire tooth surface in the meshing direction.

[0260] In this embodiment, the inclination angle gradually increases from second brush portion 271C to second brush portion 271A, and from second brush portion 271G to second brush portion 271E, so that even when the mouth is slightly open, second brush portions 271C, 271D, 271G, and 271H can fit against the tips of the teeth on the tongue side, and second brush portions 271A and 271E can fit against the gums on the tongue side.

[0261] The arrangement pitches of second brush portions 271A and 271B, second brush portions 271B and 271C, second brush portions 271C and 271D, second brush portions 271E and 271F, second brush portions 271F and 271G, and second brush portions 271G and 271H that are adjacent in the meshing direction are each offset by, for example, half a pitch in the circumferential direction. In other words, when viewed in the direction facing brush surface 261a, second brush portions 271A, 271B, 271C, 271D and second brush portions 271E, 271F, 271G, 271H are each arranged in a staggered pattern. By arranging the second brush parts 271A, 271B, 271C, 271D and the second brush parts 271E, 271F, 271G, 271H in a staggered pattern, the gaps between the second brush parts 271 can be reduced, improving the fit to the tooth surface and cleaning performance.

[0262] 29 is a front view of the first brush body 230, the second brush body 260, and the connecting portion 280, excluding the connecting portions between the first brush portion 241, the second brush portion 271, and the grip portion 210. As shown in Fig. 29, the brush surfaces 231a and 261a of the first support body 231 and the second support body 261 face each other across a gap S in the depth direction, excluding the connecting region by the connecting portion 280. In other words, the first brush portion 241 and the second brush portion 271 face each other across a gap S in the depth direction. The first support body 231 of the first brush body 230 and the second support body 261 of the second brush body 260 are capable of relative movement independently in both the depth direction and the θ direction, including deformation characteristics, when the mouthpiece portion 220 is attached to the oral cavity and used to fit the dentition.

[0263] Because the first support 231 of the first brush body 230 and the second support 261 of the second brush body 260 are able to move independently relative to each other in at least one of the depth direction and circumferential direction, when the first brush body 230 and the second brush body 260 are moved during brushing, they can move freely without being restricted by each other and fit to the dentition. Furthermore, the first support 231 of the first brush body 230 and the second support 261 of the second brush body 260 can follow the shape of the dentition and the brushing action, and by fitting to both the cheek side and the tongue side of the dentition, cleaning power is improved.

[0264] More specifically, the first support 231 and the second support 261 differ in shape characteristics or material characteristics. Shape characteristics include dimensions in the depth direction, circumferential direction, and meshing direction. Material characteristics include hardness and flexural modulus.

[0265] In this embodiment, the first support 231 and the second support 261 differ in hardness as a material characteristic. The hardness of the first support 231 is preferably greater than that of the second support 261. The first support 231 is more preferably formed of a soft resin having a Shore A hardness of 50 or more and a Shore D hardness of 75 or less. The second support 261 is more preferably formed of a soft resin having a Shore A hardness of 40 or more and a Shore D hardness of 70 or less. "Shore A hardness" refers to the durometer A hardness of plastic measured in accordance with JIS K 7215 or JIS K 6253. "Shore D hardness" refers to the hardness of durometer type D specified in JIS K 6253.

[0266] Since the outer side of the dentition in the depth direction has a large change in curvature and also has a steric hindrance due to the buccal mucosa, the second support 261 located on the outer side is made softer than the first support 231 to facilitate relative movement in the depth direction relative to the first support 231, thereby deforming the second support 261 and improving the ability of the second brush part 271 to follow the dentition. On the other hand, the inner side of the dentition has a small change in curvature and less steric hindrance, so the first support 231 located on the inner side is made harder than the second support 261 to improve the ability of the first brush part 241 to follow the dentition at the first support 231.

[0267] Furthermore, the resistance to movement in the θ direction of the first support 231 and the second support 261 also differs depending on the presence or absence of the steric hindrance and the amount of change in curvature. In this embodiment, by making the second support 261, which is located on the outer side and has greater resistance to movement, softer than the first support 231, the second support 261 can easily move and deform in the θ direction relative to the first support 231, thereby improving the ability of the second brush unit 271 to follow the dentition. Therefore, by setting the hardness within the above range and making the hardness of the first support 231 greater than that of the second support 261, the independence of the movements of the first support 231 in the first brush body 230 and the second support 261 in the second brush body 260 is increased, allowing the first brush unit 241 and the second brush unit 271 to follow the shape of the dentition and the brushing action, and improving cleaning power by fitting to the buccal and lingual sides of the dentition, respectively. Furthermore, it is more preferable that the hardness of first brush part 241 and second brush part 271 also fall within the above range. If the hardness of the soft resin is below the above lower limit, the scraping force will be insufficient and, if mouthpiece part 220 is electrically operated, vibration transmission will also be insufficient, resulting in a decrease in cleaning function. If the hardness of the soft resin exceeds the above upper limit, first brush part 241 and second brush part 271 will be less flexible, reducing fit and cleaning function.

[0268] Various elastomers, such as polyurethane and silicone, can be used as the soft resin for the first brush body 230 and the second brush body 260. Polyurethane tends to have higher tensile strength and mechanical abrasion resistance than other elastomers, such as styrene-based or polyester-based elastomers. Therefore, using polyurethane as the soft resin makes the brush less likely to break even when thin-walled, ensuring mechanical strength and long-term use. Silicone, in particular, has high heat and chemical resistance, reducing deterioration in quality when boiled for disinfection or in the presence of toothpaste.

[0269] In the first brush body 230 and the second brush body 260 of this embodiment, the first support 231 and the second support 261, which face each other in the depth direction at the same position in the θ direction, have different depth dimensions. The depth dimension L1 of the first support 231 is preferably 1.5 mm or more and 7 mm or less. The depth dimension L2 of the second support 261 is preferably 1.5 mm or more and 6 mm or less. The depth dimension L1 of the first support 231 at the end in the θ direction is larger than the depth dimension L2 of the second support 261. In other words, at the end in the θ direction, the depth dimension L2 of the second support 261 is smaller (thinner) than the depth dimension L1 of the first support 231.

[0270] The depth dimensions of the first support 231 and the second support 261 are both sufficiently small, so that the first support 231 and the second support 261 can move in accordance with the shape of the tooth row and the brushing action, thereby improving the fit of the first brush part 241 and the second brush part 271 to the tooth row and the cleaning power.

[0271] Furthermore, the depth dimension L2 of the second support 261 located on the outer side is thinner than the depth dimension L1 of the first support 231 located on the inner side, allowing each support to have different movements, fitting to the buccal and lingual sides of the dentition and improving cleaning power. Specifically, the second support 261 on the outer side, which has a large change in curvature and is also subject to steric hindrance from the buccal mucosa, is made thinner and softer than the first support 231 to improve its ability to conform to the dentition. On the other hand, the first support 231 on the inner side, which has a small change in curvature, is made thicker and less soft than the second support 261 on the outer side to improve its conformability.

[0272] It is preferable that the depth dimensions of the first support 231 and the second support 261 gradually decrease from the center to the ends in the θ direction, i.e., from the front teeth side to the back teeth side. When the mouthpiece unit 220 is moved left and right, there is a high risk that both the first brush body 230 and the second brush body 260 will come off the dentition on the back teeth side. In contrast, by gradually decreasing the depth dimensions of the first support 231 and the second support 261 from the front teeth side to the back teeth side, flexibility is increased, particularly on the back teeth side of the first support 231 and the second support 261, and the ability of the first brush unit 241 and the second brush unit 271 to follow the dentition can be improved.

[0273] As shown in Figures 25 and 26, the connecting portion 280 extends in the circumferential direction, perpendicular to the meshing direction. The connecting portion 280 has a rectangular plate shape when viewed from above. Figure 30 is a cross-sectional view taken along line D-D in Figure 26. As shown in Figure 30, the connecting portion 280 connects the first support 231 and the second support 261 in the depth direction. The connecting portion 280 connects the first support 231 and the second support 261 at their ends in the circumferential direction. The connecting portion 280 connects the first support 231 and the second support 261 at a central position in the meshing direction. The connecting portion 280 has a third brush portion 281.

[0274] The third brush part 281 has a mountain-shaped bristle height profile with a peak at the midpoint in the depth direction. The bristle height profile of the third brush part 281 can be appropriately changed or selected depending on the purpose, such as an arched or domed shape. The mountain-shaped bristle height profile of the third brush part 281 results in a profile that fits the occlusal surfaces of the teeth, improving cleaning power. The third brush part 281 is positioned, for example, opposite the molars. Because the third brush part 281 is positioned opposite the molars and protrudes upward and downward, it can effectively clean the occlusal surfaces of the molars that are difficult for the first brush part 241 and the second brush part 271 to reach.

[0275] The first support 231 and the second support 261 are opposed to each other in the depth direction, and in the length in the θ direction, the region connected by the connecting portion 280 is not separated in the depth direction, while the region not connected by the connecting portion 280 is separated in the depth direction. A gap S is formed in the region where the first support 231 and the second support 261 are separated.

[0276] As shown in Figure 29, if the length in the θ direction of the first support 231 and the second support 261 facing each other in the depth direction is L11, and the length of the area where the first support 231 and the second support 261 are separated in the depth direction is L12, the proportion of the length L12 to the length L11 is preferably 20% or more and 70% or less, and more preferably 30% or more and 60% or less.

[0277] By forming a gap S, which is a separation region between the first support 231 and the second support 261 in the depth direction, one of the first support 231 and the second support 261 can move in accordance with the tooth shape and brushing action without being constrained by the other, thereby improving the fit and cleaning power of the first brush unit 241 and the second brush unit 271 to the tooth row. If the ratio of length L12 to length L11 is less than 20%, the area connected by the connecting portion 280 will be relatively large, resulting in excessive absorption of vibrations by the connecting portion 280. Furthermore, because the separation region is small, one of the first support 231 and the second support 261 will be more likely to be constrained by the other, making it more difficult for it to move in accordance with the tooth shape and brushing action.

[0278] On the other hand, if the proportion of length L12 in length L11 exceeds 70%, the area where connecting portion 280 exists becomes relatively small, making it difficult to bridge vibrations from outer-side second support 261 to inner-side first support 231 via connecting portion 280, or vibrations from inner-side first support 231 to outer-side second support 261 via connecting portion 280. In the embodiment of Fig. 25, the vibration source is present on the outer-side second support 261 side, and vibrations are transmitted from outer-side second support 261 to inner-side first support 231.

[0279] As a result, the vibration and brushing action are insufficiently transmitted from the first support 231 to the second support 261. By setting the ratio of the length L12 to the length L11 to be 20% or more and 70% or less, the deterioration of the vibration and brushing action can be suppressed, and the cleaning power can be improved.

[0280] The connecting position of the first support 231 and the second support 261 by the connecting portion 280, where the first support 231 and the second support 261 form a non-separation region in the depth direction, is preferably on the molar side. By locating the non-separation region on the molar side, it is possible to prevent the behavior of the first support 231 and the second support 261 from being excessively different. In addition, by locating the connecting portion 280 on the molar side, it is possible to fulfill the role of brushing and cleaning the occlusal surfaces.

[0281] Furthermore, when the region of the first support 231 and the second support 261 from the position of the front teeth to the molars, i.e., the region from the center to the end in the θ direction, is taken as 100%, the connection position of the first support 231 and the second support 261 by the connection portion 280, which forms the non-separation region, is preferably at least 30% away from the vibration source. If the distance from the vibration source to the connection position of the first support 231 and the second support 261 is less than 30% of the region from the center to the end in the θ direction, vibrations may not be sufficiently transmitted to the end in the θ direction. By making the distance from the vibration source to the connection position of the first support 231 and the second support 261 at least 30% of the region from the center to the end in the θ direction, vibrations can be sufficiently transmitted to the end in the θ direction.

[0282] The connecting portion 280 that connects the first support 231 and the second support 261 is preferably formed to include at least a portion of a material that is harder than the first support 231 and the second support 261. This makes it difficult for vibrations transmitted between the first support 231 and the second support 261 to be attenuated.

[0283] As described above, in toothbrush 201 of this embodiment, first support 231 and second support 261 are capable of relative movement independently in both the depth direction and the θ direction, so that when first brush body 230 and second brush body 260 are moved during brushing, they can move freely without being restricted by each other. Therefore, in toothbrush 201 of this embodiment, first brush part 241 and second brush part 271 each fit tightly to the row of teeth, improving cleaning power and providing a strong cleaning sensation.

[0284] [Seventh embodiment of mouthpiece portion 220] Next, a seventh embodiment of the mouthpiece portion 220 will be described with reference to Fig. 31. In this figure, elements that are the same as the components of the sixth embodiment shown in Figs. 25 to 30 are given the same reference numerals, and their description will be omitted.

[0285] Fig. 31 is a front view of the mouthpiece portion 220 according to the seventh embodiment. Illustrated in Fig. 31 are connection portions between the first brush portion 241, the second brush portion 271, and the grip portion 210. As shown in Fig. 31, curved portions 232 are provided at both ends of the first support 231 in the θ direction when viewed from above, and curve outward in the depth direction from an inflection point 230a.

[0286] When viewed from above, the second support 261 is provided at both ends in the θ direction with curved portions 262 that curve inward in the depth direction starting from inflection points 260a. The curved portions 232 and 262 curve inward in the depth direction as they move outward in the θ direction. The other configurations are the same as those of the sixth embodiment.

[0287] In the mouthpiece portion 220 of this embodiment, in addition to being able to obtain the same action and effect as in the sixth embodiment, the shape of the mouthpiece portion 220 is such that for molars located at the end in the θ direction, the curved portion 232 wraps around the distal surface of the tooth from the inside, while the curved portion 262 wraps around the distal surface of the tooth from the outside, thereby further improving the tracking ability and cleaning power of the first brush portion 241 and the second brush portion 271 with respect to the molars.

[0288] Eighth Embodiment of Mouthpiece Section 220 Next, an eighth embodiment of the mouthpiece section 220 will be described with reference to Fig. 32. In this figure, elements that are the same as those in the sixth embodiment shown in Figs. 25 to 30 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0289] Fig. 32 is a front view of the mouthpiece portion 220 according to the eighth embodiment. In Fig. 32, the connection portions between the first brush portion 241, the second brush portion 271, and the grip portion 210 are not shown.

[0290] As shown in Figure 32, when viewed from above, a brush surface 231a of the first support 231 facing the gap S has a plurality of V-shaped notches 233 (four in Figure 32, for example). The notches 233 are arranged at intervals in the θ direction. The notches 233 are arranged line-symmetrically in the θ direction. When viewed from above, a brush surface 261a of the second support 261 facing the gap S has a plurality of V-shaped notches 263 (four in Figure 32, for example). The notches 263 are arranged at intervals in the θ direction. The notches 263 are arranged line-symmetrically in the θ direction. The other configurations are the same as those of the sixth embodiment.

[0291] In the mouthpiece portion 220 having the above configuration, the first support 231 has a plurality of cutouts 233 formed in the brush surface 231a, so that the first support 231 is more likely to bend outward in the depth direction than inward. On the other hand, the second support 261 has a plurality of cutouts 263 formed in the brush surface 261a, so that the second support 261 is more likely to bend inward in the depth direction than outward. Therefore, in the mouthpiece portion 220 of this embodiment, in addition to being able to obtain the same functions and effects as those of the sixth embodiment, the distance in the depth direction between the first support 231 and the second support 261 changes from a wide state to a narrow state, thereby improving the followability of the first brush portion 241 and the second brush portion 271 with respect to the row of teeth.

[0292] [Ninth embodiment of mouthpiece portion 220] Next, a ninth embodiment of the mouthpiece portion 220 will be described with reference to Fig. 33. In this figure, elements that are the same as the components of the sixth embodiment shown in Figs. 25 to 30 are given the same reference numerals, and descriptions thereof will be omitted.

[0293] Fig. 33 is a front view of the mouthpiece portion 220 according to the ninth embodiment. In Fig. 33, the connection portions between the first brush portion 241, the second brush portion 271, and the grip portion 210 are not shown.

[0294] As shown in Figure 33, when viewed from above, a plurality of V-shaped notches 234 (four in Figure 33, for example) are formed in a surface 231b of the first support 231 opposite to the brush surface 231a. The notches 234 are arranged at intervals in the θ direction. The notches 234 are arranged line-symmetrically in the θ direction. When viewed from above, a plurality of V-shaped notches 264 (four in Figure 33, for example) are formed in a surface 261b of the second support 261 opposite to the brush surface 261a that faces the gap S. The notches 264 are arranged at intervals in the θ direction. The notches 264 are arranged line-symmetrically in the θ direction. The other configurations are the same as those of the sixth embodiment.

[0295] In the mouthpiece portion 220 configured as described above, the first support 231 has a plurality of cutouts 234 formed on the surface 231b thereof, so that the first support 231 is more likely to bend inward than outward in the depth direction.

[0296] On the other hand, in the second support 261, since a plurality of notches 264 are formed in the surface 261b, the second support 261 is more likely to bend outward in the depth direction than inward. Therefore, in the mouthpiece portion 220 of this embodiment, in addition to being able to obtain the same effects and advantages as those of the sixth embodiment, the distance in the depth direction between the first support 231 and the second support 261 changes from a narrow state to a wide state, thereby improving the ability of the first brush portion 241 and the second brush portion 271 to follow the tooth row.

[0297] In the eighth embodiment of the mouthpiece portion 220, the notch 233 is formed on the brush surface 231a, and in the ninth embodiment, the notch 234 is formed on the surface 231b opposite to the brush surface 231a. However, the present invention is not limited to this configuration. For example, the notch 233 may be formed on the brush surface 231a for the molars, and the notch 234 may be formed on the surface 231b opposite to the brush surface 231a at the corner of the tooth number 3 in the θ direction. In this case, the notch 233 formed on the brush surface 231a and the notch 234 formed on the surface 231b opposite to the brush surface 231a may be appropriately mixed.

[0298] [Tenth embodiment of mouthpiece portion 220] Next, a tenth embodiment of the mouthpiece portion 220 will be described with reference to Fig. 34. In this figure, elements that are the same as those in the eighth embodiment shown in Fig. 32 are given the same reference numerals, and descriptions thereof will be omitted.

[0299] Fig. 34 is a front view of the mouthpiece portion 220 according to the tenth embodiment. In Fig. 34, the connection points between the first brush portion 241, the second brush portion 271, and the grip portion 210 are not shown.

[0300] As shown in Figure 34, when viewed from above, a plurality of semicircular notches 235 (six in Figure 34 as an example) are formed on the brush surface 231a of the first support 231 that faces the gap S. The notches 235 are arranged at intervals in the θ direction. The notches 235 are arranged line-symmetrically in the θ direction. When viewed from above, a plurality of semicircular notches 265 (six in Figure 34 as an example) are formed on the brush surface 261a of the second support 261 that faces the gap S. The notches 265 are arranged at intervals in the θ direction. The notches 265 are arranged line-symmetrically in the θ direction. The other configurations are the same as those of the eighth embodiment.

[0301] In addition to providing the same effects and advantages as those of the eighth embodiment, the mouthpiece portion 220 of this embodiment allows the curved surfaces of the semicircular cutouts 235, 265 to conform to the curved surface of one of the teeth, further improving the ability of the first brush portion 241 and the second brush portion 271 to follow the dentition. Note that the cutouts 235, 265 can also be filled with materials of different hardness to improve cleaning performance.

[0302] [Eleventh embodiment of mouthpiece portion 220] Next, an eleventh embodiment of the mouthpiece portion 220 will be described with reference to Fig. 35. In this figure, elements that are the same as those in the sixth embodiment shown in Figs. 25 to 30 are designated by the same reference numerals, and their description will be omitted.

[0303] Fig. 35 is a front view of the mouthpiece portion 220 according to the eleventh embodiment. In Fig. 35, the connection portions between the first brush portion 241, the second brush portion 271, and the grip portion 210 are not shown.

[0304] 35 , the mouthpiece portion 220 according to this embodiment has at least one of a first hard plate 236 provided on the first brush body 230 and a second hard plate 266 provided on the second brush body 260. The mouthpiece portion 220 according to this embodiment has both the first hard plate 236 and the second hard plate 266, but may be configured to have only one of them.

[0305] The first hard plate 236 is provided on the first support 231 of the first brush body 230 along the θ direction. The first hard plate 236 is embedded in the first support 231. The first hard plate 236 is formed of a resin that is harder than the first brush body 230. When a load is applied to the first support 231 inward, that is, on one side in the depth direction, the first hard plate 236 applies tension to the first support 231 outward, that is, on the other side in the depth direction. This allows the first support 231 to maintain its basic U-shape and assists it in conforming to the shape of the dentition, thereby improving the fit and cleaning power of the first brush part 241 and making it easier to insert into the oral cavity.

[0306] When the shape of the first hard plate 236 embedded in the first support 231 is the same as the shape of the first support 231 when unloaded, the first hard plate 236 maintains the basic U-shape of the first support 231, and when a force is applied through the first support 231 and the first hard plate 236 elastically deforms inward in the depth direction, it applies an elastic restoring force outward in the depth direction.

[0307] On the other hand, if the radius of curvature of the unloaded first hard plate 236 is larger than the shape of the first hard plate 236 embedded in the first support 231, the first support 231 is subjected to outward tension in the depth direction by the elastic restoring force of the first hard plate 236. Therefore, the first support 231 is less likely to bend inward in the depth direction and more likely to bend outward in the depth direction. In other words, the first support 231 has anisotropy in terms of bending characteristics in the depth direction. The radius of curvature of the unloaded first hard plate 236 is preferably 15 mm or more and 40 mm or less.

[0308] The second hard plate 266 is provided on the second support 261 of the second brush body 260 along the θ direction. The second hard plate 266 is embedded in the second support 261. The second hard plate 266 is formed of a resin that is harder than the second brush body 260. The second hard plate 266 applies tension to the second support 261 toward the inside, that is, one side in the depth direction, when a load toward the outside, that is, the other side in the depth direction, is applied to the second support 261. This allows the second support 261 to maintain its basic U-shape and assists in conforming to the shape of the dentition, thereby improving the fit and cleaning power of the second brush part 271 and making it easier to insert into the oral cavity.

[0309] When the shape of the second hard plate 266 embedded in the second support 261 is the same as the shape of the second support 261 when it is unloaded, the second hard plate 266 maintains the basic U-shape of the second support 261, and when a force is applied through the second support 261 and the second hard plate 266 elastically deforms outward in the depth direction, it applies an elastic restoring force inward in the depth direction.

[0310] On the other hand, if the radius of curvature of the unloaded second hard plate 266 is smaller than the shape of the second hard plate 266 embedded in the second support body 261, the second support body 261 is applied with tension inward in the depth direction by the elastic restoring force of the second hard plate 266. Therefore, the second support body 261 is less likely to bend outward in the depth direction, but is more likely to bend inward in the depth direction. The radius of curvature of the unloaded second hard plate 266 is preferably 20 mm or more and 60 mm or less.

[0311] The hardness of the first hard plate 236 and the second hard plate 266 is preferably equal to or greater than 50 Shore A hardness and equal to or less than 75 Shore D hardness. The hardness of the first hard plate 236 is preferably greater than the hardness of the second hard plate 266. By setting the hardness of the first hard plate 236 and the second hard plate 266 to equal to or greater than 50 Shore A hardness, vibrations can be transmitted efficiently. By setting the hardness of the first hard plate 236 and the second hard plate 266 to equal to or less than 75 Shore D hardness, the ability of the first brush portion 241 and the second brush portion 271 to follow the tooth row can be improved.

[0312] As described above, since the outer side of the tooth row in the depth direction has a large change in curvature and also has a steric obstruction due to the buccal mucosa, by making the second hard plate 266 located on the outer side softer than the first hard plate 236 and making it easier for the second brush body 260 to move in the depth direction relative to the first brush body 230, it is possible to deform the second support body 261 and improve the ability of the second brush part 271 to follow the tooth row. On the other hand, the inner side of the tooth row has a small change in curvature and less steric obstruction, so by making the first hard plate 236 located on the inner side harder than the second hard plate 266, it is possible to improve the ability of the first brush part 241 of the first brush body 230 to follow the tooth row.

[0313] The depth dimension of the first hard plate 236 and the second hard plate 266 is preferably 0.5 mm or more and 2.0 mm or less. The depth dimension of the first hard plate 236 is preferably larger than the depth dimension of the second hard plate 266. By setting the depth dimension of the first hard plate 236 and the second hard plate 266 to 0.5 mm or more, vibrations can be transmitted efficiently. By setting the depth dimension of the first hard plate 236 and the second hard plate 266 to 2.0 mm or less, the ability of the first brush portion 241 and the second brush portion 271 to follow the tooth row can be improved.

[0314] Furthermore, when the region of the first support 231 and the second support 261 from the position of the front teeth to the molars, i.e., the region from the center to the end in the θ direction, is taken as 100%, the first hard plate 236 and the second hard plate 266 preferably exist in a region that is 15% or more and 95% or less from the center in the θ direction. By having the first hard plate 236 and the second hard plate 266 exist in a region that is 15% or more from the center in the θ direction, when a load is applied inward in the depth direction to the first support 231, tension can be applied outward in the depth direction to the first support 231, and when a load is applied outward in the depth direction to the second support 261, tension can be applied inward in the depth direction to the second support 261. By having the first hard plate 236 and the second hard plate 266 exist in a region that is 95% or less from the center in the θ direction, the appliance can be used without causing any discomfort due to pressure or vibration on the teeth.

[0315] It is preferable that the depth dimensions of the first hard plate 236 and the second hard plate 266 gradually decrease from the front teeth side to the back teeth side, i.e., from the center to the ends in the θ direction. When the mouthpiece portion 220 is moved left and right, there is a high risk that both the first brush body 230 and the second brush body 260 will come off the dentition on the back teeth side. In contrast, by gradually decreasing the depth dimensions of the first hard plate 236 and the second hard plate 266 from the front teeth side to the back teeth side, the flexibility of the first hard plate 236 and the second hard plate 266, particularly on the back teeth side, is increased, and the first brush portion 241 and the second brush portion 271 can be made to conform to the dentition more easily.

[0316] It is also preferable that the dimensions of the first hard plate 236 and the second hard plate 266 in the meshing direction gradually decrease from the front teeth side to the back teeth side, i.e., from the center to the ends in the θ direction, thereby achieving the same effect as gradually decreasing the dimensions of the first hard plate 236 and the second hard plate 266 in the depth direction from the front teeth side to the back teeth side.

[0317] 31 as the seventh embodiment, it is preferable to provide curved plate portions at both ends in the θ direction of the first hard plate 236 that curve from inflection points so as to warp outward in the depth direction, and to provide curved plate portions at both ends in the θ direction of the second hard plate 266 that curve from inflection points so as to warp inward in the depth direction. This results in shapes that move differently for molars located at the ends in the θ direction, such that the curved plate portions of the first hard plate 236 wrap around the distal surfaces of the teeth from the inside, and the curved plate portions of the second hard plate 266 wrap around the distal surfaces of the teeth from the outside, thereby further improving the followability and cleaning power of the first brush unit 241 and the second brush unit 271 with respect to the molars.

[0318] 34 as the tenth embodiment, it is preferable to provide a semicircular plate cutout on the outer surface in the depth direction of the first hard plate 236, and to provide a semicircular plate cutout on the inner surface in the depth direction of the second hard plate 266. This allows the first support 231 and the second support 261 located in the plate cutout to follow one curved surface of the tooth, further improving the ability of the first brush part 241 and the second brush part 271 to follow the tooth row.

[0319] [Twelfth embodiment of mouthpiece portion 220] Next, a twelfth embodiment of the mouthpiece portion 220 will be described with reference to Fig. 36. In this figure, elements that are the same as those in the sixth embodiment shown in Figs. 25 to 30 are designated by the same reference numerals, and their description will be omitted.

[0320] Figure 36 is a cross-sectional view taken along line B-B in Figure 26, and is a partial cross-sectional view of the mouthpiece portion 220 according to the twelfth embodiment of the present invention. Figure 36 shows the behavior of the connecting portion 280 when compressed in the meshing direction. The third brush portion 281 is not shown in Figure 36.

[0321] The connecting portion 280 of this embodiment is formed of an elastic material such as rubber, for example. The connecting portion 280 elastically deforms in the depth direction in response to deformation in the meshing direction. The other configurations are the same as those of the sixth embodiment.

[0322] As shown by the solid arrows in FIG. 36 , when the connecting portion 280 is compressed in the intermeshing direction, it elastically deforms in at least the direction of extension in the depth direction. When the intermeshing direction compression is reduced, the connecting portion 280 is subjected to a force in the direction of contraction in at least the depth direction, using the elastic restoring force as a biasing force, as shown by the dashed-dotted arrows in FIG. 36 . That is, when the intermeshing direction compression is reduced, a biasing force is applied to the first support 231 in a direction outward in the depth direction, such that the first brush part 241 fits inside the row of teeth. Furthermore, when the intermeshing direction compression is reduced, a biasing force is applied to the second support 261 in a direction inward in the depth direction, such that the second brush part 271 fits outside the row of teeth. This allows the mouthpiece portion 220 of this embodiment to improve the fit and cleaning power of the first brush part 241 and the second brush part 271 to the row of teeth.

[0323] [Thirteenth embodiment of mouthpiece portion 220] Next, a thirteenth embodiment of the mouthpiece portion 220 will be described with reference to Figures 37 to 39. In these figures, elements that are the same as the components of the sixth embodiment shown in Figures 25 to 30 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0324] Figures 37 and 38 are schematic cross-sectional views taken along line BB in Figure 26, and are partial cross-sectional views of the mouthpiece portion 220 according to the thirteenth embodiment of the present invention. In Figures 37 and 38, the third brush portion 281 is not shown.

[0325] As shown in Figure 37, the connecting portion 280 of this embodiment has a gap 282. The gap 282 has a rectangular cross section and is formed inside the connecting portion 280 in the meshing direction. The gap 282 is located at the center of the connecting portion 280 in the depth direction. The depth dimension of the gap 282 is shorter than the depth dimension of the connecting portion 280. The gap 282 penetrates the connecting portion 280 in the θ direction. The other configurations are the same as those of the sixth embodiment.

[0326] When the connecting portion 280 is compressed in the interlocking direction, as shown by the solid arrow in Figure 38, at least a portion of the first support 231 and the second support 261 move closer to the center of the connecting portion 280 in the depth direction.

[0327] 38 , as the connecting portion 280 above the gap 282 deforms downward, the first support 231 above the connecting portion 280 tilts outward in the depth direction, and the second support 261 above the connecting portion 280 tilts inward in the depth direction, as shown by the dash-dotted arrows. Also, as the connecting portion 280 below the gap 282 deforms upward, as shown by the dash-dotted arrows, as the connecting portion 280 above the gap 282 deforms upward, the first support 231 below the connecting portion 280 tilts outward in the depth direction, and the second support 261 below the connecting portion 280 tilts inward in the depth direction.

[0328] This allows the first brush part 241 and the second brush part 271, which are located above the connecting part 280, to move closer to each other toward the center of the depth direction of the connecting part 280, and also allows the first brush part 241 and the second brush part 271, which are located below the connecting part 280, to move closer to each other toward the center of the depth direction of the connecting part 280, thereby improving fit to the dentition and cleaning power.

[0329] 39, the first hard plate 236 is embedded in the first support 231, and the second support 261 and second hard plate 266 are embedded in the first support 231, and when the first support 231 and the second support 261 are compressed in the meshing direction, the upper and lower sides do not tilt in the depth direction, so as shown by the arrows, they approach horizontality in the direction toward the center in the depth direction of the connecting part 280. This improves the fit to the row of teeth and the cleaning power.

[0330] [Fourteenth embodiment of mouthpiece portion 220] Next, a fourteenth embodiment of the mouthpiece portion 220 will be described with reference to Figures 40 to 43. In these figures, elements that are the same as those in the sixth embodiment shown in Figures 25 to 30 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0331] Figures 40 and 41 are schematic cross-sectional views taken along line BB in Figure 26, and are partial cross-sectional views of the mouthpiece portion 220 according to the fourteenth embodiment of the present invention. The third brush portion 281 is not shown in Figures 40 to 43.

[0332] As shown in Figure 40, the connecting portion 280 of this embodiment has grooves 283. The grooves 283 are formed on the upper and lower surfaces of the connecting portion 280 at the same position in the depth direction. A plurality of grooves 283 (two in Figure 40) are arranged on each of the upper and lower surfaces of the connecting portion 280, spaced apart from each other on either side of the center of the connecting portion 280 in the depth direction. The grooves 283 have a V-shaped cross section that opens to the surface of the connecting portion 280. The grooves 283 extend in the θ direction and are formed across the entire connecting portion 280 in the θ direction. The other configurations are similar to those of the sixth embodiment.

[0333] The connecting portion 280 has a plurality of grooves 283 formed on both sides in the meshing direction and at the same position in the depth direction, and is therefore divided into three blocks B in the depth direction by the grooves 283. Since the bending strength of the connecting portion 280 is small in the region where the grooves 283 are formed, each block B can deform relative to the adjacent block B around an axis extending in the θ direction with the bottom of the groove 283 as the center.

[0334] 41 , when the depth dimension of the lower jaw teeth is greater than the depth dimension of the upper jaw teeth during occlusion, the blocks B on both sides in the depth direction are deformed upward relative to the central block B. At this time, the lower sides of the first brush part 241 and the second brush part 271 are separated from each other, causing the upper sides of the first brush part 241 and the second brush part 271 to move closer to each other. This allows the first brush part 241 and the second brush part 271, which are positioned above the connecting part 280, to improve their fit to the teeth and their cleaning power.

[0335] In Figure 42, a gap 282 is provided in the connecting portion 280 shown in Figure 40. The gap 282 has a rectangular cross section and is formed at the center of the interior of the connecting portion 280 in the meshing direction. The length of the gap 282 in the depth direction is approximately the same as the length of the connecting portion 280 in the depth direction. By providing the gap 282, the three blocks B are separated into six: three upper blocks B and three lower blocks B.

[0336] When the connecting portion 280 shown in FIG. 42 is compressed in the occlusion direction, the upper and lower blocks B located in the center of the depth direction deform in a direction that sinks toward the gap 282, as shown in FIG. 43 . As the central block B sinks toward the gap 282, the blocks B located on both sides of the depth direction tilt toward the center of the depth direction on the upper and lower sides. As a result, the three upper blocks B curve in a curved shape that convex downward, and the three lower blocks B curve in a curved shape that convex upward. The maximum depth dimension of the three curved blocks B is shorter on the upper and lower sides. Furthermore, the three upper blocks B and the three lower blocks B are vertically symmetrical. Therefore, the first brush part 241 and the second brush part 271 approach each other in the depth direction without tilting. This improves the fit and cleaning power of the first brush part 241 and the second brush part 271 to the dentition.

[0337] [Fifteenth embodiment of mouthpiece portion 220] Next, a fifteenth embodiment of the mouthpiece portion 220 will be described with reference to Fig. 44. In this figure, elements that are the same as those in the eleventh embodiment shown in Fig. 35 are given the same reference numerals, and descriptions thereof will be omitted.

[0338] 44 is a side view of the first hard plate 236 and the second hard plate 266 as viewed from the left side. The first hard plate 236 of this embodiment has recesses 237. A plurality of recesses 237 (two in FIG. 44 ) are provided at intervals in the θ direction. The recesses 237 penetrate the first hard plate 236 in the depth direction.

[0339] The second hard plate 266 of this embodiment has recesses 267. A plurality of recesses 267 (two in FIG. 44 ) are provided at intervals in the θ direction. The recesses 267 penetrate the second hard plate 266 in the depth direction.

[0340] The recesses 237 and 267 are provided at positions where the dimensions in the θ direction, the dimension in the interlocking direction, and the dimension in the depth direction change or at positions of inflection points. As a result, in the mouthpiece portion 220 of this embodiment, in addition to being able to obtain the same functions and effects as those of the eleventh embodiment, the bending strength of the first hard plate 236 and the second hard plate 266 changes at the positions where the recesses 237 and 267 are provided, so that the fit of the first brush portion 241 and the second brush portion 271, the cleaning power including the interlocking surface, and the vibration transmission can be adjusted depending on the position of the tooth row.

[0341] The recesses 237 and 267 are not limited to a configuration in which they penetrate the first hard plate 236 and the second hard plate 266 in the depth direction, but may also be a configuration in which they penetrate in the meshing direction, or a configuration in which both a recess that penetrates in the depth direction and a recess that penetrates in the meshing direction are provided. Furthermore, in addition to a configuration in which the recesses 237 and 267 penetrate the first hard plate 236 and the second hard plate 266, they may also be a configuration in which they do not penetrate but are thin-walled, or a configuration in which they are formed from a material with a different hardness from the first hard plate 236 and the second hard plate 266. In addition, if they are formed from a material with a different hardness, they do not necessarily have to be recessed.

[0342] While the preferred embodiment of the toothbrush according to the third embodiment has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to this example. The shapes and combinations of the components shown in the above example are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0343] For example, in the above embodiment, a configuration in which the first brush portion 241 and the second brush portion 271 are provided over the entire θ direction relative to the first support 231 and the second support 261 is illustrated, but this configuration is not limited thereto, and for example, the first brush portion 241 and the second brush portion 271 may be provided intermittently in the θ direction. Furthermore, in addition to a configuration in which the mouthpiece portion 220 is provided over the entire circumferential direction, it may also be a configuration in which the first brush portion 241 and the second brush portion 271 are provided only in one of the left and right regions, for example.

[0344] In the above embodiment, a configuration in which the gap S is provided between the first support 231 and the second support 261 in the depth direction has been exemplified, but the present invention is not limited to this configuration. A configuration in which a material is provided between the first support 231 and the second support 261 in the depth direction, which allows the first support 231 and the second support 261 to move relatively independently in both the depth direction and the θ direction and allows the teeth to mesh with each other may also be used.

[0345] In addition, in the above embodiment, the first brush part 241 and the second brush part 271 may be filaments integrally molded with the first support 231 and the second support 261, respectively, or may be bundles of bristles provided on the first support 231 and the second support 261, respectively.

[0346] [Fourth Embodiment of Toothbrush] A fourth embodiment of the toothbrush will now be described with reference to Figs.

[0347] Figure 45 is a front view of toothbrush 301. As shown in Figure 45, toothbrush 301 is a mouthpiece-type toothbrush and has a grip portion 310 and a connector 320. Hereinafter, connector 320 will be referred to as mouthpiece portion 320. Vibrations are imparted to mouthpiece portion 320 via grip portion 310. A shaft 314 protrudes from grip portion 310 and is connected to mouthpiece portion 320. Note that a configuration in which shaft 314 protruding from mouthpiece portion 320 is connected to grip portion 310 may also be used. Vibrations are imparted to mouthpiece portion 320 from grip portion 310 via shaft 314.

[0348] The present invention is applicable to any of a configuration in which a brushing action is manually applied from grip portion 310 to mouthpiece portion 320 in up-down, left-right, front-rear, or a combination thereof, a configuration in which vibration is manually applied, and a configuration in which vibration is electrically applied from grip portion 310 to mouthpiece portion 320. In this embodiment, an electric drive unit is provided in grip portion 310, and vibrations generated by the drive of the electric drive unit are applied to mouthpiece portion 320.

[0349] The electric drive unit includes a power supply 311, a vibration element 312, and a control unit 313. The control unit 313 drives the vibration element 312 using power from the power supply 311. The power supply 311 is configured, for example, with a rechargeable battery or other device. The vibration element 312 is configured, for example, with a piezoelectric element, an electromagnetic acoustic transducer, an unbalanced motor, or other device. The vibration generated by the vibration element 312 is a vibration that rotates around an axis extending in the depth direction and repeatedly reverses its rotational direction at a predetermined rotation angle. A shaft 314 connected to the electric drive unit in the grip 310 vibrates by repeatedly reversing its rotational direction. When the vibration element 312 drives the shaft 314, the mouthpiece 320 vibrates by repeatedly reversing its rotational direction.

[0350] [Sixteenth embodiment of mouthpiece portion 320] The mouthpiece portion 320 has a first brush body 330, a second brush body 360, an adjustment portion 350, and a connecting portion 380. The first brush body 330 is located inside the grip portion 310 in the depth direction. The second brush body 360 is located between the grip portion 310 and the first brush body 330 in the depth direction, and is spaced apart from the first brush body 330. The second brush body 360 is located with a gap S between it and the first brush body 330. The gap S is a space that passes through the mouthpiece portion 320 in the meshing direction.

[0351] When the mouthpiece part 320 is attached to the oral cavity, the first brush body 330 is positioned on the tongue side, which is inside the row of teeth, and the second brush body 360 is positioned on the cheek side, which is outside the row of teeth.

[0352] The first brush body 330 has a first support 331 and a first brush portion 341. The first support 331 supports the base end side of the first brush portion 341. When viewed from above, the first support 331 is formed in a U-shape (horseshoe shape) along the circumferential direction centered on the axis J. The first support 331 is open to the inside.

[0353] The second brush body 360 has a second support 361 and a second brush portion 371. The second support 361 supports the base end side of the second brush portion 371. When viewed from above, the second support 361 is formed in a U-shape (horseshoe shape) along the circumferential direction centered on the axis J. The second support 361 is open to the inside.

[0354] The range in which the first brush body 330 and the second brush body 360 face the tooth row is not limited to the entire tooth row, but may be a configuration in which they face only a portion of the front teeth (central incisors, lateral incisors), canines, and molars (first premolars, second premolars, first molars, second molars).

[0355] Figure 46 is an external perspective view of the mouthpiece portion 320 as seen from the inside in the depth direction. Figure 47 is a cross-sectional view taken along the line B-B in Figure 46. As shown in Figures 46 and 47, the dimension of the first support 331 in the interlocking direction is largest on the outside in the depth direction and gradually decreases toward the inside. The upper end of the first support 331 is located at the top on the outside in the depth direction and gradually slopes downward toward the inside. The lower end of the first support 331 is located at the bottom on the outside in the depth direction and gradually slopes upward toward the inside.

[0356] The dimension of the second support 361 in the meshing direction is largest on the outside in the depth direction and gradually decreases toward the inside. The upper end of the second support 361 is located at the top on the outside in the depth direction and gradually slopes downward toward the inside. The lower end of the second support 361 is located at the bottom on the outside in the depth direction and gradually slopes upward toward the inside.

[0357] The maximum dimension in the interlocking direction of the second support 361 at the outer side in the depth direction is larger than the maximum dimension in the interlocking direction of the first support 331 at the outer side in the depth direction. The minimum dimension in the interlocking direction of the second support 361 at the inner side in the depth direction is larger than the minimum dimension in the interlocking direction of the first support 331 at the inner side in the depth direction. The dimension in the interlocking direction of the second support 361 is larger than the dimension in the interlocking direction of the first support 331 throughout the entire depth direction.

[0358] Figure 48 is a cross-sectional view taken along the line CC in Figure 45. As shown in Figure 48, the first brush portions 341 are provided on the first support 331 at intervals above and below. The first brush portions 341 are provided on the upper and lower end sides of the first support 331. The first brush portions 341 extend outward in the depth direction from the outer brush surface 331a in the depth direction of the first support 331. The brush surface 331a has a portion that is curved in the circumferential direction in a direction that convex outward when viewed from above.

[0359] This embodiment is a toothbrush 301 that uses a first brush part 341 that is aligned along the tooth row and is intended to be moved manually or electrically, so the curved brush surface 331a allows the first brush part 341 to be aligned along the tongue side of the tooth row, improving cleaning performance and fit. It also maximizes the installation area of ​​the first brush part 341, which, when electrically operated, contributes to improved vibration efficiency and cleaning power.

[0360] The first brush portion 341 includes first brush portions 341A, 341B, 341C and first brush portions 341D, 341E, 341F. The first brush portions 341A, 341B, 341C and the first brush portions 341D, 341E, 341F extend outward in the depth direction from the brush surface 331a. The first brush portion 341A extends outward from the upper end of the brush surface 331a. The first brush portion 341B extends outward from a position lower than the first brush portion 341A. The first brush portion 341C extends outward from a position lower than the first brush portion 341B. The first brush portion 341D extends outward from the lower end of the brush surface 331a. First brush portion 341E extends outward from a position higher than first brush portion 341D. First brush portion 341F extends outward from a position higher than first brush portion 341E. As shown in Figures 45 and 46 , a plurality of first brush portions 341 including first brush portions 341A, 341B, 341C and first brush portions 341D, 341E, 341F are provided at intervals throughout the entire circumferential direction.

[0361] If the position where the upper and lower teeth mate in the occlusion direction is defined as occlusion surface K, the inclination angle of the first brush part 341 relative to occlusion surface K in a side view parallel to occlusion surface K becomes smaller the closer it is to occlusion surface K and becomes larger the farther it is from occlusion surface K. Specifically, the inclination angle of the first brush parts 341A and 341D, which are closer to the gums and farthest from the occlusion surface K, is larger than the inclination angles of the first brush parts 341B and 341E and the first brush parts 341C and 341F. The inclination angle of the first brush parts 341C and 341F, which are closest to the occlusion surface K, is smaller than the inclination angles of the first brush parts 341A and 341D and the first brush parts 341B and 341E.

[0362] The mouth tends to open slightly when the mouthpiece portion 320 is held in the mouth. Furthermore, the dimension of the tooth surface in the meshing direction is often larger than the arrangement pitch in the meshing direction at the base of first brush portion 341A and first brush portion 341C and the arrangement pitch in the meshing direction at the base of first brush portion 341D and first brush portion 341F. Therefore, if the inclination angles of first brush portions 341A to 341C and 341D to 341F are the same, it will be difficult for the tips of first brush portions 341A to 341C and 341D to 341F to cover the entire tooth surface in the meshing direction.

[0363] In this embodiment, the inclination angle gradually increases from first brush portion 341C to first brush portion 341A, and from first brush portion 341F to first brush portion 341D, so that even when the mouth is slightly open, first brush portions 341C and 341F can fit against the tips of the teeth on the tongue side, and first brush portions 341A and 341D can fit against the gums on the tongue side.

[0364] The circumferential arrangement pitches of adjacent first brush portions 341A and 341B, first brush portions 341B and 341C, first brush portions 341D and 341E, and first brush portions 341E and 341F in the meshing direction are offset by, for example, half a pitch. That is, when viewed in the direction facing the brush surface 331a, the first brush portions 341A, 341B, 341C and the first brush portions 341D, 341E, 341F are arranged in a staggered pattern. By arranging the first brush portions 341A, 341B, 341C and the first brush portions 341D, 341E, 341F in a staggered pattern, the gaps between the first brush portions 341 can be reduced, improving fit to the tooth surface and cleaning performance.

[0365] The second brush portions 371 are provided at intervals above and below the second support 361. The second brush portions 371 are provided at the upper and lower ends of the second support 361. The second brush portions 371 extend inward in the depth direction from the brush surface 61a on the inner side in the depth direction of the second support 361. The brush surface 61a has a portion that is curved in the circumferential direction so as to be convex outward when viewed from above.

[0366] This embodiment of the toothbrush 301 uses the second brush part 371, which is aligned along the tooth row and is designed to be moved manually or electrically. Therefore, the curved brush surface 61a allows the second brush part 371 to be aligned along the cheek side of the tooth row, improving cleaning performance and fit. Furthermore, it is possible to maximize the installation area of ​​the second brush part 371, which, when electrically operated, contributes to improved vibration efficiency and cleaning power.

[0367] The second brush portion 371 includes second brush portions 371A, 371B, 371C, and 371D and second brush portions 371E, 371F, 371G, and 371H. Second brush portions 371A, 371B, 371C, and 371D and second brush portions 371E, 371F, 371G, and 371H extend inward in the depth direction from the brush surface 361a. Second brush portion 371A extends outward from the upper end of the brush surface 361a. Second brush portion 371B extends inward from a position lower than second brush portion 371A. Second brush portion 371C extends inward from a position lower than second brush portion 371B. Second brush portion 371D extends inward from a position lower than second brush portion 371C.

[0368] Second brush portion 371E extends inward from the lower end of brush surface 361a. Second brush portion 371F extends inward from a position higher than second brush portion 371E. Second brush portion 371G extends inward from a position higher than second brush portion 371F. Second brush portion 371H extends inward from a position higher than second brush portion 371G. As shown in FIGS. 45 and 46 , multiple second brush portions 371, including second brush portions 371A, 371B, 371C, 371D and second brush portions 371E, 371F, 371G, 371H, are provided at intervals throughout the entire circumferential direction.

[0369] In a side view parallel to the occlusal surface K, the inclination angle of the second brush portion 371 relative to the occlusal surface K decreases the closer it is to the occlusal surface K and increases the farther it is from the occlusal surface K. Specifically, the inclination angles of the second brush portions 371A and 371E, which are closer to the gums and farthest from the occlusal surface K, are greater than the inclination angles of the second brush portions 371B to 371D and 371F to 371H. The inclination angles of the second brush portions 371C, 371D, 371G, and 371H, which are closer to the occlusal surface K, are smaller than the inclination angles of the second brush portions 371A and 371B and the second brush portions 371E and 371F. As an example, the inclination angles of the second brush portions 371C and 371D are the same, and the inclination angles of the second brush portions 371G and 371H are the same. The inclination angle of the second brush portion 371D may be smaller than the inclination angle of the second brush portion 371C, and the inclination angle of the second brush portion 371H may be smaller than the inclination angle of the second brush portion 371G.

[0370] The mouth tends to open slightly when mouthpiece portion 320 is held in the mouth. Furthermore, the dimension of the tooth surface in the meshing direction is often larger than the arrangement pitch in the meshing direction at the base of second brush portion 371A and second brush portion 371D and the arrangement pitch in the meshing direction at the base of second brush portion 371E and second brush portion 371H. Therefore, if the inclination angles of second brush portions 371A to 371D and 371E to 371H are the same, it will be difficult for the tips of second brush portions 371A to 371D and 371E to 371H to cover the entire tooth surface in the meshing direction.

[0371] In this embodiment, the inclination angle gradually increases from second brush portion 371C to second brush portion 371A, and from second brush portion 371G to second brush portion 371E, so that even when the mouth is slightly open, second brush portions 371C, 371D, 371G, and 371H can fit against the tips of the teeth on the tongue side, and second brush portions 371A and 371E can fit against the gums on the tongue side.

[0372] The arrangement pitches of second brush portions 371A and 371B, second brush portions 371B and 371C, second brush portions 371C and 371D, second brush portions 371E and 371F, second brush portions 371F and 371G, and second brush portions 371G and 371H that are adjacent in the meshing direction are shifted by, for example, half a pitch in the circumferential direction. In other words, when viewed in the direction facing brush surface 361a, second brush portions 371A, 371B, 371C, and 371D and second brush portions 371E, 371F, 371G, and 371H are each arranged in a staggered pattern. By arranging the second brush parts 371A, 371B, 371C, 371D and the second brush parts 371E, 371F, 371G, 371H in a staggered pattern, the gaps between the second brush parts 371 can be reduced, improving the fit to the tooth surface and cleaning performance.

[0373] 49 is a front view of the first brush body 330, the second brush body 360, and the connecting portion 380, excluding the connecting portions between the first brush portion 341, the second brush portion 371, and the grip portion 310. The adjustment portion 350 is capable of adjusting the distance in the depth direction between the first support 331 and the second support 361 in an unloaded state. The unloaded state of the first support 331 and the second support 361 refers to a state in which no load is applied, such as load from the teeth or cheeks in the oral cavity, other than gravity and loads generated when the user adjusts the distance.

[0374] 49 , the adjustment section 350 has a fitting protrusion 351 and a fitting cylinder 356. The fitting protrusion 351 is provided on the first support 331. The fitting protrusion 351 protrudes outward from the first support 331 and is located in the gap S. The fitting cylinder 356 is provided at a position facing the fitting protrusion 351 in the depth direction of the second support 361. The fitting cylinder 356 protrudes inward from the second support 361 and is located in the gap S.

[0375] FIG. 50 is a front view showing a state in which the fitting protrusion 351 and the fitting cylindrical portion 356 are spaced apart in the depth direction. As shown in FIG. 50 , the fitting protrusion 351 has a pair of fitting pieces 352. The pair of fitting pieces 352 extend parallel to each other and outward at a circumferentially spaced interval. The pair of fitting pieces 352 are elastically deformable in the circumferential direction, moving away from and toward each other. Each of the pair of fitting pieces 352 has a protrusion 353 and a slope 354. The protrusion 353 protrudes outward in the circumferential direction from the fitting piece 352. The protrusion 353 tapers toward the tip. The slope 354 is located at the outer tip of the fitting piece 352. The slope 354 extends from the outer end of the fitting piece 352 in the depth direction toward the inside of the depth direction, and then extends outward in the circumferential direction to connect to the tip of the protrusion 353.

[0376] The fitting cylinder 356 has a rectangular cylindrical shape extending inward from the second support 361. A circumferential distance W3 on an inner surface 357 of the fitting cylinder 356 is smaller than a distance W1 between the tips of the pair of protrusions 353 and is larger than a distance W2 between the outer ends in the depth direction of the pair of inclined surfaces 354. Figure 51 is a front view showing a state in which the fitting protrusion 351 is inserted into the fitting cylinder 356.

[0377] As shown in Figure 51 , the fitting protrusion 351 can be inserted into the fitting cylindrical portion 356 from the inside in the depth direction. When the fitting protrusion 351 is inserted into the fitting cylindrical portion 356, the inclined surface 354 comes into contact with the inner end of the inner surface 357 in the depth direction, causing the pair of fitting pieces 352 to elastically deform in directions approaching each other in the circumferential direction, as shown by the arrows in Figure 51 , and the fitting protrusion 351 is inserted into the fitting cylindrical portion 356 in a state where the protrusion 353 comes into contact with the inner surface 357 from the inside in the circumferential direction and fits into it. The elastic restoring force of the fitting pieces 352 that have elastically deformed and been inserted into the fitting cylindrical portion 356 acts as a biasing force that presses the inner surface 357 of the fitting cylindrical portion 356 outward in the circumferential direction via the protrusion 353.

[0378] As a result, when the fitting protrusion 351 inserted into the fitting cylindrical portion 356 moves in the depth direction relative to the fitting cylindrical portion 356, the frictional force between the protrusion 353 and the inner surface 357 acts as a resisting force. Therefore, the relative positional relationship between the fitting protrusion 351 and the fitting cylindrical portion 356 in the depth direction is maintained unless a force (load) exceeding the frictional force between the protrusion 353 and the inner surface 357 is applied. Furthermore, as shown in FIGS. 47 and 48 , the fitting protrusion 351 engages with the inner surface 357 of the fitting cylindrical portion 356 in the meshing direction and is held movable in the depth direction. Therefore, the relative positional relationship between the fitting protrusion 351 and the fitting cylindrical portion 356 in the depth direction can be adjusted by applying a force (load) exceeding the frictional force between the protrusion 353 and the inner surface 357 to move the fitting protrusion 351 relative to the fitting cylindrical portion 356.

[0379] This makes it possible to adjust the depth direction distance between the first support 331 and the second support 361 in an unloaded state. Furthermore, because the fitting protrusion 351 and the fitting cylinder 356 are slidable in the depth direction with the protrusion 353 in contact with the inner surface 357, it is possible to continuously change the depth direction distance between the first support 331 and the second support 361 in accordance with the load applied when adjusting the depth direction distance to the adjustment unit 350. Therefore, the depth direction distance between the first support 331 and the second support 361 in an unloaded state can be adjusted to any value.

[0380] Therefore, by adjusting the depthwise distance between the first support 331 and the second support 361 in accordance with differences in the depthwise dimensions, such as between men and women, or between adults and children, it is possible to improve the fit to the dentition. Furthermore, in this embodiment, the depthwise distance between the first support 331 and the second support 361 can be continuously changed in accordance with the load, so that when the mouthpiece part 320 is attached to the oral cavity, in addition to during the distance adjustment operation, the distance changes due to the load associated with brushing, thereby further improving the fit to the dentition.

[0381] As shown in FIGS. 47 and 48 , the adjustment unit 350 preferably includes a third brush portion 358 on at least one of the upper and lower sides in the interdigital direction. In this embodiment, the third brush portion 358 is provided on both the upper and lower sides of the adjustment unit 350 in the interdigital direction. The third brush portion 358 is provided on the upper and lower sides of the fitting tube portion 356, respectively. The third brush portion 358 has a mountain-shaped bristle height profile that peaks at the midpoint in the depth direction. The mountain-shaped bristle height profile of the third brush portion 358 results in a profile that fits the interdigital surfaces of the teeth, improving cleaning power. The third brush portion 358 is positioned, for example, opposite the front teeth. Because the third brush portion 358 is positioned opposite the front teeth and protrudes upward and downward, it can effectively clean the interdigital surfaces of the front teeth that are difficult to reach with the first brush portion 341 and the second brush portion 371.

[0382] One or more adjustment units 350 can be provided at any position in the circumferential direction, but it is preferable to place them at least at the circumferential center positions of the first support 331 and the second support 361. As shown in Fig. 49 , the circumferential center position refers to an area within ±10% of the maximum width H of the first support 331 and the second support 361, with the circumferential center as the reference. The maximum width H is the maximum dimension of the first support 331 and the second support 361 in the tangential direction at the circumferential center when viewed from the front.

[0383] Since the first support 331 and the second support 361 extend circumferentially with different circumferential curvatures, by positioning the adjustment unit 350 at the circumferential central position of the first support 331 and the second support 361, when adjusting the depth distance between the first support 331 and the second support 361 at the central position, it is possible to adjust the depth distance to a different distance from the distance adjusted at the central position depending on the circumferential position.

[0384] When the adjustment unit 350 is disposed at the center in the circumferential direction, the shaft 314 that imparts vibrations to the first support 331 and the second support 361 is located in the same region as the adjustment unit 350, and the vibrations to the first support 331 and the second support 361 are less likely to attenuate, thereby improving cleaning power. When the adjustment unit 350 is disposed at the center in the circumferential direction, it is preferable that the shaft 314 reach the first support 331, from the viewpoint of enhancing the above-mentioned effect.

[0385] The depth direction distance between the first support 331 and the second support 361 obtained by the adjustment unit 350 is preferably 4 mm or more and 18 mm or less when the adjustment unit 350 is positioned at the circumferential center position corresponding to the front teeth. If the distance adjustment amount by the adjustment unit 350 is less than 4 mm, it may come into contact with the teeth and become impossible to move. If the distance adjustment amount by the adjustment unit 350 exceeds 18 mm, the first support 331 may come into contact with the tongue and the second support 361 may come into contact with the lips, which may impair operability. By setting the distance adjustment amount by the adjustment unit 350 to 4 mm or more and 18 mm or less, it is possible to adjust the brush to fit the dentition regardless of the brush length.

[0386] The depth direction distance between the first support 331 and the second support 361 obtained by the adjustment unit 350 is preferably 7 mm or more and 21 mm or less when the adjustment unit 350 is positioned between the front teeth and the back teeth, or when positioned at the back teeth. If the distance adjustment amount by the adjustment unit 350 is less than 7 mm, there is a possibility that the adjustment unit 350 will come into contact with the teeth and become unable to move. If the distance adjustment amount by the adjustment unit 350 is more than 21 mm, there is a possibility that the first support 331 will come into contact with the tongue and the second support 361 will come into contact with the lips, thereby impairing operability.

[0387] By setting the distance adjustment amount by the adjustment unit 350 to 7 mm or more and 21 mm or less, it becomes possible to adjust the brush to fit the dentition regardless of the brush length. As described above, by providing a sufficient distance adjustment amount for each position where the adjustment unit 350 is placed, it is possible to adapt it to any oral cavity size and improve the fit.

[0388] In this embodiment, the first support 331 and the second support 361 differ in hardness as a material characteristic. The hardness of the first support 331 is preferably greater than that of the second support 361. The first support 331 is more preferably formed of a soft resin having a Shore A hardness of 50 or more and a Shore D hardness of 75 or less. The second support 361 is more preferably formed of a soft resin having a Shore A hardness of 40 or more and a Shore D hardness of 70 or less. "Shore A hardness" refers to the durometer A hardness of plastic measured in accordance with JIS K 7215 or JIS K 6253. "Shore D hardness" refers to the hardness of durometer type D specified in JIS K 6253.

[0389] Since the outer side of the dentition in the depth direction has a large change in curvature and also has a steric hindrance due to the buccal mucosa, the second support 361 located on the outer side is made softer than the first support 331 to facilitate relative movement in the depth direction relative to the first support 331, thereby deforming the second support 361 and improving the ability of the second brush part 371 to follow the dentition. On the other hand, the inner side of the dentition has a small change in curvature and less steric hindrance, so the first support 331 located on the inner side is made harder than the second support 361 to improve the ability of the first brush part 341 to follow the dentition at the first support 331.

[0390] Furthermore, the resistance to movement in the θ direction of the first support 331 and the second support 361 also differs depending on the presence or absence of the steric hindrance and the amount of change in curvature. In this embodiment, by making the second support 361, which is located on the outer side and has greater resistance to movement, softer than the first support 331, the second support 361 can easily move and deform in the θ direction relative to the first support 331, thereby improving the ability of the second brush unit 371 to follow the dentition. Therefore, by setting the hardness within the above range and making the hardness of the first support 331 greater than that of the second support 361, the independence of the movements of the first support 331 in the first brush body 330 and the second support 361 in the second brush body 360 is increased, allowing the first brush unit 341 and the second brush unit 371 to follow the shape of the dentition and the brushing motion, and improving cleaning power by fitting to the buccal and lingual sides of the dentition. Furthermore, it is more preferable that the hardness of first brush part 341 and second brush part 371 also fall within the above range. If the hardness of the soft resin is below the above lower limit, the scraping force will be insufficient and, if mouthpiece part 320 is electrically operated, vibration transmission will also be insufficient, resulting in a decrease in cleaning function. If the hardness of the soft resin exceeds the above upper limit, first brush part 341 and second brush part 371 will be less flexible, reducing fit and cleaning function.

[0391] Various elastomers, such as polyurethane and silicone, can be used as the soft resin forming the first brush body 330 and the second brush body 360. Polyurethane tends to have higher tensile strength and mechanical abrasion resistance than other elastomers, such as styrene-based or polyester-based elastomers. Therefore, using polyurethane as the soft resin makes the brush less likely to break even when thin-walled, ensuring mechanical strength and long-term use. Silicone, in particular, has high heat and chemical resistance, reducing deterioration in quality when boiled for disinfection or in the presence of toothpaste.

[0392] In the first brush body 330 and the second brush body 360 of this embodiment, the first support 331 and the second support 361, which face each other in the depth direction at the same position in the θ direction, have different depth dimensions. The depth dimension L1 of the first support 331 is preferably 1.5 mm or more and 7 mm or less. The depth dimension L2 of the second support 361 is preferably 1.5 mm or more and 6 mm or less. The depth dimension L1 of the first support 331 at the end in the θ direction is larger than the depth dimension L2 of the second support 361 at that end in the θ direction. In other words, the depth dimension L2 of the second support 361 at the end in the θ direction is smaller (thinner) than the depth dimension L1 of the first support 331.

[0393] The depth dimensions of the first support 331 and the second support 361 are both sufficiently small, so that the first support 331 and the second support 361 can move in accordance with the shape of the tooth row and the brushing action, thereby improving the fit of the first brush part 341 and the second brush part 371 to the tooth row and the cleaning power.

[0394] Furthermore, the depth dimension L2 of the second support 361 located on the outer side is thinner than the depth dimension L1 of the first support 331 located on the inner side, allowing each support to have different movements, fitting to the buccal and lingual sides of the dentition and improving cleaning power. Specifically, the second support 361 on the outer side, which has a large change in curvature and is also subject to steric hindrance from the buccal mucosa, is made thinner and softer than the first support 331 to improve its ability to conform to the dentition. On the other hand, the first support 331 on the inner side, which has a smaller change in curvature, is made thicker and less soft than the second support 361 on the outer side to improve its conformability.

[0395] As shown in Figures 45, 46, and 49, the connecting portion 380 extends in the circumferential direction, perpendicular to the meshing direction. When viewed from above, the connecting portion 380 has a rectangular plate shape. The connecting portion 380 connects the first support 331 and the second support 361 in the depth direction. The connecting portion 380 connects the first support 331 and the second support 361 at their ends in the circumferential direction. The connecting portion 380 connects the first support 331 and the second support 361 at a central position in the meshing direction.

[0396] As shown in FIG. 46 , the connecting portion 380 has a fourth brush portion 381. The fourth brush portion 381 has a mountain-shaped bristle height profile that peaks at the midpoint in the depth direction. The mountain-shaped bristle height profile of the fourth brush portion 381 results in a profile that fits the occlusal surfaces of the teeth, improving cleaning power. The fourth brush portion 381 is positioned, for example, opposite the molars. Because the fourth brush portion 381 is positioned opposite the molars and protrudes upward and downward, it can effectively clean the occlusal surfaces of the molars that are difficult for the first brush portion 341 and the second brush portion 371 to reach.

[0397] The first support 331 and the second support 361 are opposed to each other in the depth direction, and the region connected by the connecting portion 380 is not separated in the depth direction within the length in the θ direction, while the region not connected by the connecting portion 380 is separated in the depth direction. In other words, the first support 331 and the second support 361 have a region where they are separated in the depth direction. A gap S is formed in the region where the first support 331 and the second support 361 are separated.

[0398] The gap S, which is a separation region between the first support 331 and the second support 361 in the depth direction, does not hinder the movement (position adjustment) of the adjustment unit 350, making it easier for the user to adjust the distance. Furthermore, the distance between the separation region can be adjusted to follow the movement of the adjustment unit 350, further improving fit. Furthermore, one of the first support 331 and the second support 361 can move in accordance with the tooth shape and brushing motion without being constrained by the other, improving the fit and cleaning power of the first brush unit 341 and the second brush unit 371 relative to the tooth row. Furthermore, because the first support 331 and the second support 361 can vibrate independently, each can improve fit to the tooth row and improve cleaning power. Furthermore, since the brush can be operated left and right with the mouth closed, drooling can be prevented.

[0399] As shown in FIG. 49 , the gap S, which is the region where the first support 331 and the second support 361 are separated in the depth direction, is defined as L11, the length in the θ direction where the first support 331 and the second support 361 face each other in the depth direction, and L12, the length of the region where the first support 331 and the second support 361 are separated in the depth direction. The ratio of the length L12 to the length L11 is preferably 30% or more and 70% or less. If the ratio of the length L12 to the length L11 is less than 30%, when adjusting the depth distance between the first support 331 and the second support 361 using the adjustment unit 350, at least one of the first support 331 and the second support 361 will be less likely to move, resulting in a reduced distance adjustment function. If the ratio of the length L12 to the length L11 is more than 70%, the region where the adjustment unit 350 exists will be smaller, limiting the region affected by the distance adjustment by the adjustment unit 350 in the circumferential direction and reducing the distance adjustment function. Furthermore, the transmission rate of vibration between the first support 331 and the second support 361 becomes insufficient.

[0400] As for the circumferential positional relationship between the adjustment unit 350 and the connecting unit 380, in addition to the configuration in which the adjustment unit 350 is arranged in the circumferential center position and the connecting unit 380 is arranged at both circumferential ends as described above, a configuration in which the adjustment unit 350 is arranged in the circumferential center position without the connecting unit 380 being arranged at either of the circumferential ends, a configuration in which the connecting unit 380 is arranged in the circumferential center position and the adjustment unit 350 is arranged at both circumferential ends, or a configuration in which the adjustment unit 350 is arranged in the circumferential center position and at both circumferential ends without the connecting unit 380 being arranged may be selected.

[0401] In a configuration in which the adjustment part 350 is positioned at the circumferential center position and the connecting parts 380 are positioned at both circumferential ends, the connecting part 380 at the position of the last molar can fit the tooth row by pulling the first support 331 or the second support 361 depending on the change in the distance between the first support 331 and the second support 361 in the adjustment part 350.

[0402] In the case of a configuration in which the connecting portion 380 is not placed at either end in the circumferential direction but the adjustment portion 350 is placed in the central position in the circumferential direction, by ensuring the maximum separation area between the first support 331 and the second support 361, the operation of the adjustment portion 350 is not hindered, and the peripheral distance can be easily changed to follow the operation of the adjustment portion 350, thereby further improving the fit.

[0403] In a configuration in which the connecting portion 380 is disposed at the circumferential center and the adjustment portions 350 are disposed at both circumferential ends, a separation area can be secured around the adjustment portion 350, which does not hinder the operation of the adjustment portion 350 and also makes it easier to change the peripheral distance to follow the operation of the adjustment portion 350, thereby further improving the fit. In addition, because the first support 331 and the second support 361 are connected by the connecting portion 380 at the circumferential center, the mouthpiece portion 320 does not wobble and the shape can be stabilized after the distance is adjusted.

[0404] In a configuration in which the adjustment units 350 are disposed at the circumferential center and both circumferential ends without the connecting unit 380, the areas other than the adjustment unit 350 become the separation area. This ensures a sufficient separation area around the adjustment unit 350, which does not impede the operation of the adjustment unit 350. Furthermore, the peripheral distance can be easily adjusted to follow the operation of the adjustment unit 350, further improving fit. Additionally, because the first support 331 and the second support 361 are connected by the adjustment unit 350 at the circumferential center, the mouthpiece unit 320 does not wobble and can maintain a stable shape after distance adjustment. Furthermore, the distance adjustment function in the depth direction and the direction of the maximum width H described above can be maximized.

[0405] As described above, the toothbrush 301 of this embodiment is provided with an adjustment unit 350 that can adjust the depthwise distance between the first support 331 and the second support 361 in an unloaded state. Therefore, by adjusting the depthwise distance between the first support 331 and the second support 361 to correspond to differences in depthwise dimensions, such as between men and women, or between adults and children, it is possible to improve the fit to the dentition.

[0406] In the above embodiment, a configuration in which an engaging protrusion 351 is provided on the first support 331 and an engaging tube portion 356 is provided on the second support 361 is exemplified, but this configuration is not limited to this, and a configuration in which an engaging tube portion 356 is provided on the first support 331 and an engaging protrusion 351 is provided on the second support 361 may also be used.

[0407] [Seventeenth embodiment of mouthpiece portion 320] Next, a seventeenth embodiment of the mouthpiece portion 320 will be described with reference to Fig. 52. In this figure, elements that are the same as those in the sixteenth embodiment shown in Figs. 45 to 51 are designated by the same reference numerals, and descriptions thereof will be omitted.

[0408] Fig. 52 is a front view of the mouthpiece part 320 according to the seventeenth embodiment. In Fig. 52, the connection parts between the first brush part 341, the second brush part 371 and the grip part 310 are not shown.

[0409] 52, the mouthpiece portion 320 according to this embodiment has at least one of a first hard plate 336 provided on the first brush body 330 and a second hard plate 366 provided on the second brush body 360. The mouthpiece portion 320 according to this embodiment has both the first hard plate 336 and the second hard plate 366, but may be configured to have only one of them.

[0410] The first hard plate 336 is provided on the first support 331 of the first brush body 330 along the θ direction. The first hard plate 336 is embedded in the first support 331. The first hard plate 336 is formed of a resin that is harder than the first brush body 330. When a load is applied to the first support 331 inward, that is, on one side in the depth direction, the first hard plate 336 applies tension to the first support 331 outward, that is, on the other side in the depth direction. This allows the first support 331 to maintain its basic U-shape and assists it in conforming to the shape of the dentition, thereby improving the fit and cleaning power of the first brush part 341 and making it easier to insert into the oral cavity.

[0411] When the shape of the first hard plate 336 embedded in the first support 331 is the same as the shape of the first support 331 when unloaded, the first hard plate 336 maintains the basic U-shape of the first support 331, and when a force is applied through the first support 331 and the first hard plate 336 elastically deforms inward in the depth direction, it applies an elastic restoring force outward in the depth direction.

[0412] On the other hand, when the radius of curvature of the unloaded first hard plate 336 is larger than the shape of the first hard plate 336 embedded in the first support 331, tension is applied to the first support 331 outward in the depth direction by the elastic restoring force of the first hard plate 336. Therefore, the first support 331 is less likely to bend inward in the depth direction, but is more likely to bend outward in the depth direction. In other words, the first support 331 has anisotropy with respect to its bending characteristics in the depth direction.

[0413] The second hard plate 366 is provided on the second support 361 of the second brush body 360 along the θ direction. The second hard plate 366 is embedded in the second support 361. The second hard plate 366 is formed of a resin that is harder than the second brush body 360. The second hard plate 366 applies tension to the second support 361 toward the inside, that is, one side in the depth direction, when a load toward the outside, that is, the other side in the depth direction, is applied to the second support 361. This allows the second support 361 to maintain its basic U-shape and assists in conforming to the shape of the dentition, thereby improving the fit and cleaning power of the second brush part 371 and making it easier to insert into the oral cavity.

[0414] When the shape of the second hard plate 366 embedded in the second support 361 is the same as the shape of the second support 361 when it is unloaded, the second hard plate 366 maintains the basic U-shape of the second support 361, and when a force is applied through the second support 361 and the second hard plate 366 elastically deforms outward in the depth direction, it applies an elastic restoring force inward in the depth direction.

[0415] On the other hand, when the radius of curvature of the unloaded second hard plate 366 is smaller than the shape of the second hard plate 366 embedded in the second support 361, tension is applied to the second support 361 inward in the depth direction by the elastic restoring force of the second hard plate 366. Therefore, the second support 361 is less likely to bend outward in the depth direction, but is more likely to bend inward in the depth direction.

[0416] Furthermore, because the first hard plate 336 is embedded in the first support 331 and the second hard plate 366 is embedded in the second support 361, when the adjustment unit 350 adjusts the depth direction distance between the first support 331 and the second support 361, the distance adjustment function can be easily extended to the vicinity of the tip of the first hard plate 336 or the second hard plate 366, even if the portion of the first support 331 or the second support 361 is far from the adjustment unit 350. Furthermore, vibration can be transmitted with reduced attenuation sequentially to the shaft 314, the second support 361 (second hard plate 366), the adjustment unit 350 and the connecting unit 380, and the first support 331 (first hard plate 336), thereby improving the cleaning power for the dentition.

[0417] The hardness of the first hard plate 336 and the second hard plate 366 is preferably equal to or greater than 50 Shore A hardness and equal to or less than 75 Shore D hardness. The hardness of the first hard plate 336 is preferably greater than the hardness of the second hard plate 366. By setting the hardness of the first hard plate 336 and the second hard plate 366 to equal to or greater than 50 Shore A hardness, vibrations can be transmitted efficiently. By setting the hardness of the first hard plate 336 and the second hard plate 366 to equal to or less than 75 Shore D hardness, the ability of the first brush portion 341 and the second brush portion 371 to follow the tooth row can be improved.

[0418] The depth dimension of the first hard plate 336 and the second hard plate 366 is preferably 0.5 mm or more and 2.0 mm or less. The depth dimension of the first hard plate 336 is preferably larger than the depth dimension of the second hard plate 366. By setting the depth dimension of the first hard plate 336 and the second hard plate 366 to 0.5 mm or more, vibrations can be transmitted efficiently. By setting the depth dimension of the first hard plate 336 and the second hard plate 366 to 2.0 mm or less, the ability of the first brush portion 341 and the second brush portion 371 to follow the tooth row can be improved.

[0419] The material constituting the first hard plate 336 and the second hard plate 366 is preferably a material that easily achieves both strength and appropriate tension, such as silicone, urethane, acrylic, copper plate, stainless steel, etc. Among these, materials other than stainless steel are more preferable from the viewpoints of adhesiveness and recyclability.

[0420] [Eighteenth embodiment of mouthpiece portion 320] Next, an eighteenth embodiment of the mouthpiece portion 320 will be described with reference to Fig. 53. In this figure, elements that are the same as those in the sixteenth embodiment shown in Figs. 45 to 51 are given the same reference numerals, and their description will be omitted. In the eighteenth embodiment, the configuration of the fitting cylinder portion 356 in the adjustment portion 350 is different.

[0421] As shown in Figure 53, the fitting cylinder portion 356 of the adjustment portion 350 has fitting recesses 368 on the inner surface 357. The fitting recesses 368 are provided in pairs at the same depth position on the inner surfaces 357 located on both sides in the circumferential direction. The fitting recesses 368 are each recessed outward in the circumferential direction from the inner surface 357. A plurality of pairs of fitting recesses 368 (four pairs in Figure 53) are provided at a fixed interval in the depth direction. The other configuration is the same as that of the sixteenth embodiment.

[0422] The protrusion 353 of the fitting protrusion 351, which has been elastically deformed and inserted into the fitting cylindrical portion 356, fits into the paired fitting recesses 368 at the same position in the depth direction from the inside in the circumferential direction by elastic restoring force. By fitting the protrusion 353 of the fitting protrusion 351 into the fitting recess 368, the distance in the depth direction between the first support body 331 and the second support body 361 is adjusted to a value according to the position of the fitting recess 368 in the depth direction.

[0423] Then, when the protrusion 353 moves the fitting protrusion 351 fitted into the fitting recess 368 in the depth direction, the pair of fitting pieces 352 elastically deform in directions approaching each other in the circumferential direction, and the protrusion 353 fits into the inner surface 357. Furthermore, when the fitting protrusion 351 is moved in the depth direction, the protrusion 353 fits from the inside in the circumferential direction due to elastic restoring force into the fitting recess 368 adjacent in the depth direction to the fitting recess 368 with which it was previously fitted.

[0424] As a result, the distance in the depth direction between the first support 331 and the second support 361 is adjusted to a value different from that when the protrusion 353 was previously fitted into the fitting recess 368, depending on the depth direction position of the newly fitted fitting recess 368. That is, in the adjustment unit 350 of this embodiment, the distance in the depth direction between the first support 331 and the second support 361 is adjusted in stages.

[0425] In the above embodiment, a configuration in which an engaging protrusion 351 is provided on the first support 331 and an engaging tube portion 356 is provided on the second support 361 is exemplified, but this configuration is not limited to this, and in this embodiment, a configuration in which an engaging tube portion 356 is provided on the first support 331 and an engaging protrusion 351 is provided on the second support 361 may also be used.

[0426] [Nineteenth embodiment of mouthpiece portion 320] Next, a nineteenth embodiment of the mouthpiece portion 320 will be described with reference to Fig. 54. In this figure, elements that are the same as those in the sixteenth embodiment shown in Figs. 45 to 51 are designated by the same reference numerals, and their description will be omitted. In the nineteenth embodiment, the configuration of the adjustment portion 350 is different.

[0427] As shown in Figure 54, the adjustment unit 350 has a nut portion 351A and a screw shaft 356A. The nut portion 351A is fixed to the first support 331. The nut portion 351A has a female thread extending in the depth direction. The screw shaft 356A faces the nut portion 351A in the depth direction and extends inward from the second support 361. The screw shaft 356A extends in the depth direction and has a female thread that meshes with the female thread of the nut portion 351A. The other configurations are the same as those of the sixteenth embodiment.

[0428] In the mouthpiece unit 320 of this embodiment, by rotating one of the first support 331 and the second support 361 relative to the other and threading the male thread into the female thread, the depthwise distance between the first support 331 and the second support 361 can be adjusted to be shorter depending on the product of the number of rotations and the thread pitch. Conversely, by rotating the male thread in a direction that loosens the female thread, the depthwise distance between the first support 331 and the second support 361 can be adjusted to be longer depending on the product of the number of rotations and the thread pitch. The adjustment unit 350 of this embodiment can adjust the depthwise distance between the first support 331 and the second support 361 in stages depending on the product of the number of rotations and the thread pitch.

[0429] In the above embodiment, the configuration in which the nut portion 351A is provided on the first support body 331 and the screw shaft 356A is provided on the second support body 361 is exemplified, but the present invention is not limited to this configuration, and the screw shaft 356A may be provided on the first support body 331 and the nut portion 351A may be provided on the second support body 361. Alternatively, the screw shaft 356A may extend inward from the grip portion 310, penetrating the second support body 361, and mesh with the nut portion 351A fixed to the first support body 331.

[0430] [Twentieth Embodiment of Mouthpiece Section 320] Next, a twentieth embodiment of the mouthpiece section 320 will be described with reference to Fig. 55. In this figure, elements that are the same as those in the sixteenth embodiment shown in Figs. 45 to 51 are designated by the same reference numerals, and their description will be omitted. In the twentieth embodiment, the configuration of the adjustment section 350 is different.

[0431] As shown in Figure 55, the adjustment unit 350 has a tubular expandable section 356B. The tubular expandable section 356B has multiple (four in Figure 55) cylinders 367 of different diameters lined up in the depth direction. The cylinder 367 on the base end side, which has the largest diameter, is fixed to the second support 361. The cylinder 367 on the tip end side, which has the smallest diameter, is fixed to the first support 331.

[0432] The multiple cylinders 367 are arranged so that a cylinder 367 with a smaller diameter (called a small cylinder) is inserted from the outside in the depth direction into a cylinder 367 with a larger diameter (called a large cylinder) that is adjacent to the cylinder 367 in the depth direction and protrudes inward. The outer circumferential surface of the small cylinder is fitted into the inner circumferential surface of the large cylinder so as to be relatively movable in the depth direction. The small cylinder is engaged with the large cylinder from the outside in the depth direction, thereby restricting the length of its outward protrusion in the depth direction.

[0433] The above-mentioned cylindrical telescopic section 356B has a maximum depth length when all of the cylinders 367 have moved outward in the depth direction, which is the minimum distance in the depth direction between the first support 331 and the second support 361, and a maximum depth length when all of the cylinders 367 have moved inward in the depth direction and are engaged with adjacent cylinders 367, which is the maximum distance in the depth direction between the first support 331 and the second support 361.

[0434] Therefore, in the cylindrical expandable portion 356B, the adjustment portion 350 can set the depth direction distance between the first support 331 and the second support 361 by using the frictional force between the outer peripheral surface of the small cylinder and the inner peripheral surface of the large cylinder. Furthermore, in the cylindrical expandable portion 356B, the adjustment portion 350 can adjust the depth direction distance between the first support 331 and the second support 361 to any value by moving the cylinder 367 in the depth direction.

[0435] That is, the adjustment unit 350 can continuously change the distance in the depth direction between the first support 331 and the second support 361 in accordance with the load applied when adjusting the distance in the depth direction on the adjustment unit 350. Furthermore, in this embodiment, the distance in the depth direction between the first support 331 and the second support 361 can be continuously changed in accordance with the load, so that when the mouthpiece unit 320 is attached to the oral cavity, in addition to during the distance adjustment operation, the distance changes due to the load associated with brushing, thereby further improving the fit to the dentition.

[0436] In the above embodiment, a configuration has been described in which the distal cylinder 367 having the smallest diameter is fixed to the first support 331, and the proximal cylinder 367 having the largest diameter is fixed to the second support 361. However, the present invention is not limited to this configuration, and a configuration in which the proximal cylinder 367 having the largest diameter is fixed to the first support 331, and the distal cylinder 367 having the smallest diameter is fixed to the second support 361 may also be used. Alternatively, the tubular extendable portion 356B may extend inward from the grip portion 310, penetrating the second support 361, and the distal cylinder 367 having the smallest diameter may be fixed to the first support 331.

[0437] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based ...

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