Toothbrush

Abstract

To provide a toothbrush with a wide head that has excellent operability.SOLUTION: A toothbrush 1 includes multiple short bristle tufts 7 and multiple long bristle tufts 8, 9 including multiple long bristle tufts 12, 13 that are longer than the short bristle tufts 7. The maximum horizontal length of a head part 3 is 15 mm or more, the length of the long bristle tufts 12, 13 is 12 mm or less, and the value obtained by dividing the thickness of the head part 3 by the length of the long bristle tufts 12, 13 is 0.23 or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to toothbrushes. [Background technology]

[0002] In recent years, wide-head toothbrushes (referred to as "wide toothbrushes" in this disclosure) that can brush a wide area of ​​the teeth with one brushing have become popular. Wide toothbrushes have larger vertical and horizontal dimensions of the head than regular compact-head toothbrushes, and have a larger contact area with the teeth. Therefore, for people who are not good at brushing with a toothbrush and have difficulty moving the toothbrush in small movements, they can brush their teeth easily and efficiently. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-185447 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, wide toothbrushes have a problem in that the head portion is large and difficult to move in the oral cavity, making it difficult for the user to operate. If the maneuverability of a wide toothbrush is poor, there is a possibility that plaque will remain in the oral cavity when brushing the teeth.

[0005] In order to solve the above problems, the present disclosure aims to provide a toothbrush with a wide head that is easy to operate. [Means for solving the problem]

[0006] In order to solve the above problems, the toothbrush of the present disclosure encompasses as its subject the toothbrush described in item 1 below.

[0007] Item 1. A toothbrush in which a plurality of bristles are bundled and planted in a plurality of bristles planting holes formed in the head portion, The hair brush comprises a plurality of short hair bundles and a plurality of long hair bundles including a plurality of long hair bundles having a hair length longer than that of the short hair bundles. The maximum lateral length of the head portion is 15 mm or more, The hair length of the long hair is 12 mm or less, The toothbrush, wherein the value obtained by dividing the thickness of the head portion by the length of the long bristles is 0.23 or more.

[0008] Furthermore, the toothbrush of the present disclosure encompasses the toothbrush described in Item 2 below as a preferred embodiment of the toothbrush described in Item 1 above.

[0009] Item 2. The toothbrush according to item 1, wherein the thickness of the long bristles is 6 mil or less.

[0010] Furthermore, the toothbrush of the present disclosure encompasses the toothbrush described in the following item 3 as a preferred embodiment of the toothbrush described in items 1 and 2 above.

[0011] Item 3. The toothbrush according to item 1 or 2, wherein the thickness of the head portion is 2.5 mm or more and 3.5 mm or less. Effect of the Invention

[0012] According to the present disclosure, a toothbrush with a wide head that is easy to operate can be provided. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a plan view showing a schematic configuration of a toothbrush according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged plan view of the head portion of the toothbrush of FIG. [Diagram 3] FIG. 3 is an enlarged side view of the head portion of the toothbrush of FIG. [Figure 4] FIG. 4 is a diagram illustrating the area of ​​the front end portion of the head portion of the toothbrush in FIG. [Diagram 5] FIG. 5 is a cross-sectional view for explaining bristles contained in each of the first hair bundle, the second hair bundle, and the third hair bundle. [Figure 6] FIG. 6 is a diagram for explaining the twist of the long bristles included in the second bristle bundle. [Figure 7] FIG. 7 is a diagram illustrating the use of the toothbrush of FIG. [Figure 8] FIG. 8 is a diagram illustrating the use of the toothbrush of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the toothbrush of the present disclosure will be described with reference to the attached drawings. In this disclosure, unless otherwise specified, the vertical direction shown in FIG. 1 corresponds to the longitudinal direction of the handle 2 and head 3, and the horizontal direction corresponds to the width direction (direction perpendicular to the longitudinal direction) of the handle 2 and head 3. The direction perpendicular to both the vertical and horizontal directions is the height or thickness direction. In the vertical direction, the tip side where the head 3 is connected to the handle 2 is the "front side", and the opposite side is the "rear side".

[0015] Fig. 1 shows the appearance of toothbrush 1 of this embodiment. Fig. 2 shows an enlarged view of the appearance of head portion 3 of toothbrush 1. Toothbrush 1 includes a long, rod-shaped handle portion 2, a thin, flat head portion 3 connected to the tip of handle portion 2, and a plurality of bristle bundles 7-9 provided on head portion 3.

[0016] As shown in FIG. 1, the handle 2 is a portion that a user holds when using the toothbrush 1. The handle 2 has a dimension that is longer in the vertical direction than the head 3. The handle 2 may be molded integrally with the head 3, or may be formed as a separate member from the head 3, with the head 3 joined to the tip of the handle 2. The handle 2 of this embodiment is made of a material such as polypropylene resin, and is molded integrally with the head 3. The outer shape and cross section (cross section perpendicular to the vertical direction of the handle 2) of the handle 2 are not particularly limited, and various shapes that have been known in the art can be adopted.

[0017] 2, head portion 3 has a generally octagonal shape that is elongated in the vertical direction when viewed from above, for example, with the four corners of a rectangle gently cut off. Head portion 3 is preferably symmetrical (bilaterally symmetrical) with respect to a center line that is parallel to the vertical direction and passes through the center in the horizontal direction.

[0018] The front end 4, which is a part of the front end side in the vertical direction of the head part 3, is formed in a tapered shape in which the horizontal length (width) gradually decreases toward the front in a plan view. In other words, the left and right side edges 40, 41 of the front end 4 extend so as to approach each other toward the front. The left and right side edges 40, 41 of the front end 4 are connected to a tip edge 42 (the tip of the head part 3). The tip edge 42 of the front end 4 extends linearly in the left-right direction, or in a convex, concave, or zigzag curved shape, and the front end 4 has, for example, a triangular shape (including an approximately triangular shape with rounded tip corners) or a trapezoid shape (including an approximately trapezoid shape with rounded two tip corners) in a plan view. The front end 4 does not necessarily have to be formed in a triangular shape or trapezoid shape in a plan view, and may be formed in a tapered shape while being curved overall, such as a semicircular shape or semielliptical shape.

[0019] The rear end 5, which is a part of the vertical rear end side of the head 3, is formed in a narrowed shape in which the horizontal length (width) gradually decreases toward the rear in a plan view. In other words, the left and right side edges 50, 51 of the rear end 5 extend so as to approach each other toward the rear. The rear end 5 is not particularly limited, but may have a substantially inverted trapezoid shape, for example. The left and right side edges 50, 51 of the rear end 5 are connected to the left and right side edges of the handle 2. The boundary between the head 3 and the handle 2 is the position of the boundary line if a clear boundary line is shown. On the other hand, if the head 3 and the handle 2 are seamlessly molded as one piece, the boundary between the head 3 and the handle 2 can be determined based on the position where the head 3 is narrowest on the inside, or the position where the thickness changes if the head 3 and the handle 2 have different thicknesses.

[0020] In a plan view, an intermediate portion 6 between the front end portion 4 and the rear end portion 5 of the head portion 3 has left and right side edges 60, 61 that extend parallel to each other in the front-rear direction. The intermediate portion 6 of the head portion 3 is not particularly limited, but may have, for example, a substantially rectangular shape.

[0021] The tapered front end 4 of the head 3 increases the force with which the toothbrush 1 penetrates into the oral cavity, allowing the toothbrush 1 to clean even the back teeth well. In addition, the discomfort felt by the user due to the tip of the head 3 touching the cheek can be reduced. The shape of the head 3 in a plan view is not limited to a substantially octagonal shape, and various known shapes can be adopted.

[0022] From the viewpoint of favorably increasing the force of the toothbrush 1 entering the oral cavity, the area of ​​the front end 4 of the head portion 3 in plan view is preferably set as follows. Specifically, as shown in FIG. 3, the area of ​​the front end 4 (area of ​​the part painted in gray in FIG. 3) is preferably 75% or less, more preferably 65% ​​or less, in terms of the ratio to the area of ​​a virtual rectangle 16 in plan view, in which the vertical length L1 of the front end 4 is the length of the short side and the maximum horizontal length L2 of the front end 4 (=the maximum horizontal length W of the head portion 3) is the length of the long side. According to this, the front end 4 can increase the taper angle (the gradient angle of each side edge 40, 41) in plan view. Therefore, the force of the toothbrush 1 entering the oral cavity is favorably increased, and the toothbrush 1 can be used to clean even the back teeth.

[0023] In this disclosure, all areas of the head portion 3 refer to the area of ​​the front surface 30 which is the bristles implanted surface.

[0024] As shown in FIG. 2, the maximum horizontal length W of the head part 3 (the horizontal length of the middle part 6 in this embodiment) is 15 mm or more and 20 mm or less, and preferably 15 mm or more and 18 mm or less. If the head part 3 is wide and the maximum horizontal length W is 15 mm or more, the number of bristle bundles 7-9 that can be arranged side by side in the head part 3 increases, and a large cleaning area can be secured by the head part 3. If the head part 3 is wide and the maximum length W is 15 mm or more, preferably six or more bristle bundles 7-9 can be arranged side by side, more preferably seven or more. On the other hand, if the maximum length W is 20 mm or less, the head part 3 can be easily handled in the oral cavity even if it is wide.

[0025] The thickness of the head portion 3 is preferably 2.5 mm to 3.5 mm, more preferably 2.8 mm to 3.3 mm. By forming the head portion 3 thin while maintaining a certain degree of strength, the toothbrush 1 can be more easily inserted into the oral cavity, allowing the toothbrush 1 to clean well even the back teeth.

[0026] The front surface 30 of the head portion 3 forms a tufting surface. A plurality of tufting holes 10 (shown in FIG. 4) are formed on the front surface 30 of the head portion 3. The plurality of tufting holes 10 are arranged at intervals in the vertical and horizontal directions on the front surface 30 of the head portion 3. The shape of the tufting holes 10 is not particularly limited, and examples thereof include a circle, an ellipse, a polygon, etc. in a plan view. It is preferable that the shapes and dimensions of the plurality of tufting holes 10 are all substantially the same. For example, if the shape of the tufting holes 10 is a circle in a plan view, the dimensions of the tufting holes 10 can be exemplified as a diameter of 1.40 mm to 1.60 mm, preferably 1.45 mm to 1.55 mm.

[0027] As shown in Fig. 4, a bristle bundle 7-9 consisting of a bundle of bristles is implanted in each of the multiple bristle implantation holes 10. For example, each bristle bundle 7-9 is made by bundling a bundle of bristles and folding it in half, attaching a known flat wire 18 to the folded portion, and driving and fixing the folded portion together with the flat wire 18 into the bristle implantation hole 10, thereby implanting it in each bristle implantation hole 10. Examples of materials for the bristles include saturated polyester resins such as polybutylene terephthalate, nylon, etc., but it is preferable to use polybutylene terephthalate as the material for the bristles from the viewpoint of high durability.

[0028] As shown in Fig. 2, the multiple bristle bundles 7-9 are arranged on the front surface 30 of the head unit 3 at intervals in the vertical and horizontal directions of the head unit 3 according to the arrangement of the multiple bristle implantation holes 10. In this embodiment, the multiple bristle bundles 7-9 include three types of bristle bundles, namely, multiple first bristle bundles 7, multiple second bristle bundles 8, and multiple third bristle bundles 8. In Fig. 2, for ease of explanation, the bristle bundles are colored according to type, with the first bristle bundles 7 indicated by black circles, the second bristle bundles 8 indicated by white circles, and the third bristle bundles 8 indicated by gray circles.

[0029] The first bristle bundles 7 are arranged in the horizontal center of the head portion 3. The first bristle bundles 7 are arranged continuously along the vertical direction of the head portion 3, forming a first bristle bundle group extending in the vertical direction. The first bristle bundles 7 are provided on the head portion 3 mainly for the purpose of cleaning the tooth surfaces when brushing the teeth.

[0030] The first hair bundle group extends from a position that is a predetermined length away from the tip of the head portion 3 (the tip edge 42 of the front end portion 4) in the vertical direction to the vicinity of the boundary between the head portion 3 and the handle portion 2. At least one first hair bundle 7 is arranged along the horizontal direction of the head portion 3, and the number of first hair bundles 7 arranged in the horizontal direction varies depending on the vertical position of the head portion 3. In this embodiment, the first hair bundles 7 are arranged in the horizontal direction in the order of 3, 3, 4, 4, 4, 2, 1, 1 from the front side in the vertical direction of the head portion 3. Note that the first hair bundles 7 do not necessarily need to be arranged in a straight line in the horizontal direction, and may be arranged in a convex curve as in this embodiment, or may be arranged in a concave or zigzag curve.

[0031] Some of the second bristle bundles 8 are arranged on both sides of the lateral side of the head unit 3, more so than the first bristle bundle group. In other words, some of the second bristle bundles 8 are arranged so as to sandwich the first bristle bundle group from the lateral side. The second bristle bundles 8 sandwiching the first bristle bundle group from the lateral side are provided on the head unit 3 mainly for the purpose of cleaning periodontal pockets when brushing teeth. At least one second bristle bundle 8 sandwiching the first bristle bundle group from the lateral side is arranged along the lateral side of the head unit 3, and the number of second bristle bundles 8 arranged in the lateral direction varies depending on the vertical position of the head unit 3. In this embodiment, the second bristle bundles 8 are arranged in the lateral direction, one, one, one, one, one, two, two, in order from the front side of the vertical direction of the head unit 3.

[0032] Further, some of the second bristle bundles 8 are arranged in a tip region 43 (shown in FIG. 5) of the front end portion 4, which is located forward of the first bristle bundle group. The second bristle bundles 8, which are arranged forward of the first bristle bundle group, are provided on the head portion 3 mainly for the purpose of cleaning between the teeth and the back teeth when brushing the teeth.

[0033] In this disclosure, the tip region 43 of the front end 4 is a region extending from the tip of the head portion 3 (tip edge 42 of the front end 4) to a position spaced a predetermined length vertically, as shown in Fig. 5. In other words, the tip region 43 is a region surrounded by the front edge 42 of the front end 4, the left and right side edges 40, 41 of the front end 4, and an imaginary line extending laterally between the left and right side edges 40, 41 of the front end 4 (the region painted gray in Fig. 5).

[0034] In this embodiment, the tip region 43 is located in front of the three first hair bundles 7 in the front row of the first hair bundle group. At least one hair implantation hole 10, preferably a plurality of hair implantation holes 10, are formed in the tip region 43, and a second hair bundle 8 is implanted in each of the hair implantation holes 10. In this embodiment, six second hair bundles 8 are arranged in the tip region 43.

[0035] The second bristle bundles 8 in the tip region 43 may be arranged in a single row in the horizontal direction, but are preferably arranged in at least two rows of at least one second bristle bundle 8 arranged in the horizontal direction in the vertical direction. In this embodiment, the six second bristle bundles 8 in the tip region 43 are arranged in rows of two and four in the horizontal direction from the front side. This allows the second bristle bundles 8 arranged in the tip region 43 to clean the back teeth well when brushing the teeth.

[0036] From the viewpoint of being able to clean the molars well with the toothbrush 1, the area of ​​the tip region 43 of the front end portion 4 is preferably set as follows, as will be described in detail later. Specifically, in terms of the area of ​​the tip region 43 in a plan view, it is preferable that the area of ​​the tip region 43 is 8% or more and 15% or less, and more preferably 8% or more and 11% or less, as a ratio to the area of ​​the head portion 3 in a plan view. In the head portion 3, the tip region 43 of the front end portion 4 is a portion that reaches the molars when the toothbrush 1 is advanced into the oral cavity. If the area of ​​the tip region 43 is large, a large number of second bristle bundles 8 for cleaning the molars can be arranged accordingly, and therefore the molars can be cleaned well by the second bristle bundles 8 arranged in the tip region 43. On the other hand, if the area of ​​the tip region 43 is 15% or less of the area of ​​the head portion 3, the molars can be cleaned well.

[0037] As shown in FIG. 2, the third bristle bundles 9 are arranged on both outer sides of the second bristle bundles 8 in the lateral direction of the head portion 3. In other words, the third bristle bundles 9 are arranged so as to sandwich some of the second bristle bundles 8 in the lateral direction. In this embodiment, the third bristle bundles 9 are continuously lined up one by one in the vertical direction along the left and right side edges 60, 61 of the widest central portion 6 in the head portion 3. The third bristle bundle 9 is arranged on the outermost side of the three types of bristle bundles 7-9 in the lateral direction of the head portion 3. The third bristle bundle 9 is provided on the head portion 3 mainly for the purpose of stimulating the gums when brushing teeth.

[0038] In the present disclosure, the first hair bundle 7 may be referred to as the "inner hair bundle", and the second hair bundle 8 and the third hair bundle 9 may be collectively referred to as the "outer hair bundle".

[0039] As described above, the second hair bundles 8 and the third hair bundles 9 are arranged on the left and right of the first hair bundles 7 in the first hair bundle group, and the second hair bundles 8 are arranged in front of the first hair bundle 7 in the forefront row in the first hair bundle group. On the other hand, there are no second hair bundles 8 or third hair bundles 9 behind the last first hair bundle 7 in the first hair bundle group.

[0040] Therefore, the multiple second hair bundles 8 and the third hair bundles 9 are arranged to surround the first hair bundle group, except for the rearmost part in the vertical direction of the head portion 3. In other words, the first hair bundle group is not completely surrounded by the multiple second hair bundles 8 and the third hair bundles 9, and the rearmost first hair bundle 7 in the first hair bundle group, which is arranged closest to the handle portion 2, is exposed from the surrounding of the multiple second hair bundles 8 and the third hair bundles 9.

[0041] The rearmost first hair bundle 7 may be aligned horizontally with the rearmost two second hair bundles 8, but it is preferable that the rearmost first hair bundle 7 protrudes further rearward than the rearmost two second hair bundles 8.

[0042] It is preferable that the rearmost first hair bundle 7 has the smallest number of first hair bundles 7 arranged horizontally in the first hair bundle group. In this embodiment, the first hair bundle group has 3, 3, 4, 4, 4, 2, 1, 1 first hair bundles 7 arranged horizontally in the vertical direction of the head part 3 from the front side, and the rearmost and second-to-last first hair bundles 7 have the smallest number of first hair bundles 7 arranged horizontally.

[0043] In addition, it is preferable that some of the first hair bundles 7 near the rear end of the first hair bundle group are arranged in the vertical direction of the head part 3 while the number of first hair bundles 7 arranged in the horizontal direction is reduced toward the rear to the minimum number. In this embodiment, for example, from the fourth hair bundle from the rear, the number of first hair bundles 7 arranged in the horizontal direction is gradually reduced to the minimum number of one, such as four, two, one, one, and so on. In accordance with this, the multiple second hair bundles 8 and third hair bundles 9 sandwiching the first hair bundle group from the horizontal direction extend inward in the horizontal direction near the rearmost first hair bundle 7 of the first hair bundle group, forming a narrowed portion 17 at the rearmost part of the first hair bundle group.

[0044] The number of first hair bundles 7 aligned in the horizontal direction may gradually decrease to the minimum number, for example, from the fourth last to the fourth last, such as 4, 3, 2, 1, and so on, and the number of first hair bundles 7 aligned in the horizontal direction may be different between the last and second last. Also, the number of first hair bundles 7 aligned in the horizontal direction may suddenly decrease to the minimum number of 1, for example, from the fourth last to the fourth last, such as 4, 4, 3, 1, or 4, 4, 1, 1, etc.

[0045] As in this embodiment, the minimum number is preferably 1. In the first hair bundle group, the number of first hair bundles 7 that are not surrounded by the plurality of second hair bundles 8 and third hair bundles 9 is as small as 1, so that the plurality of second hair bundles 8 and third hair bundles 9 can surround the first hair bundle group while making the narrowed portion 17 as small as possible.

[0046] Each of the above-mentioned first hair bundle 7, second hair bundle 8 and third hair bundle 9 is an assembly of a large number of bristles, but the first hair bundle 7 is composed of a plurality of short bristles 11, while the second hair bundle 8 and third hair bundle 9 are mainly composed of a plurality of long bristles 12, 13, which have a long bristles.

[0047] In this disclosure, the first hair bundle 7, which is composed of a plurality of short hairs 11, may be referred to as the "short hair bundle," and the second hair bundle 8 and the third hair bundle 9, which are mainly composed of a plurality of long hairs 12, 13, may be collectively referred to as the "long hair bundle."

[0048] As shown in Fig. 4, the short bristles 11 included in the first bristle bundle 7 have a shorter bristles length than the long bristles 12, 13 included in the second bristle bundle 8 and the third bristle bundle 9. It is preferable that the short bristles 11 constituting the first bristle bundle 7 all have the same bristles length, from the viewpoint of uniformly cleaning the tooth surface during brushing. The concept of bristles having the same bristles length includes not only cases where the bristles are exactly the same length, but also cases where the bristles are substantially the same length (for example, the difference in bristles length is about 1 mm).

[0049] The bristles length of the short bristles 11 included in the first bristle bundle 7 is preferably 8 mm or more and 12 mm or less, more preferably 8 mm or more and 10 mm or less, so as to enable good cleaning of the tooth surface during brushing.

[0050] In the present disclosure, the bristles 11-15 refer to lengths from the front surface 30 of the head unit 3 to the tips of the respective bristles. When there is variation in the bristles of the multiple bristles, the average of the bristles of the multiple bristles is regarded as the bristles of the respective bristles.

[0051] The short bristles 11 included in the first bristle bundle 7 can be of various shapes known for bristles used in toothbrushes, such as flat bristles having a roughly uniform thickness over the entire length, round bristles with rounded tips, branched bristles with a portion of the tip branched, tapered bristles with at least a portion of the tip tapered, etc. The short bristles 11 are preferably round bristles from the viewpoints of being less prone to bending and being able to effectively remove plaque adhering to the tooth surface.

[0052] From the viewpoint of improving the cleaning effect of the short bristles 11 when brushing teeth, the cross-sectional shape of the short bristles 11 included in the first bristle bundle 7 is preferably a polygonal shape, and preferably a regular square shape, a regular hexagon shape, etc. Note that the cross-sectional shape of the short bristles 11 may be a circle, etc.

[0053] From the standpoint of cleaning effect and irritation to the gums, the thickness of the short bristles 11 contained in the first bristle bundle 7 is preferably 6 mils or more and 9 mils or less (0.1524 mm or more and 0.2286 mm or less), and more preferably 6 mils or more and 8 mils or less (0.1524 mm or more and 0.2032 mm or less).

[0054] In the present disclosure, the thickness of each of the bristles 11-15 is the thickness measured at the root of the bristles (a portion 5 mm away from the front surface 30 of the head part 3). The thickness of the bristles is the maximum thickness in the cross section of the bristles. When the cross section of the bristles is, for example, a circular shape, the maximum thickness is the diameter, and when the cross section of the bristles is a regular square or regular hexagon, the maximum thickness is the length of the diagonal. The thickness of the bristles can be measured by pinching the root of the bristles using a digital thickness gauge.

[0055] The number of short bristles 11 included in the first bristle bundle 7 is preferably 16 or more and 30 or less, and more preferably 16 or more and 24 or less.

[0056] As shown in FIG. 4, the bristles 12 for long length included in the second bristle bundle 8 are longer than the bristles 11 for short length included in the first bristle bundle 7. The bristles 12 for long length have a bristles length of preferably 9 mm or more, more preferably 10 mm or more, so that the bristles 12 can enter and clean periodontal pockets or gaps during tooth brushing. The bristles 12 for long length are shorter than the bristles of a general wide toothbrush, at 12 mm or less, so that the total height of the toothbrush 1 (the sum of the thickness of the head portion 3 and the bristles lengths of the long bristles 12 and 13 included in the second bristle bundle 8 and the third bristle bundle 9) can be reduced. This increases the force of the toothbrush 1 to enter the oral cavity, allowing the toothbrush 1 to clean even the back teeth well.

[0057] The difference in bristle length between the long bristles 12 included in the second bristle bundle 8 and the short bristles 11 included in the first bristle bundle 7 is preferably greater than 1.0 mm and less than 3.0 mm, more preferably 1.5 mm or more and 2.5 mm or less. If the difference in bristle length between the long bristles 12 and the short bristles 11 is small, the long bristles 12 are less likely to enter periodontal pockets or gaps between teeth when brushing, and if the difference in bristle length between the long bristles 12 and the short bristles 11 is large, the short bristles 11 are less likely to contact the tooth surface when brushing. When the difference in bristle length between the long bristles 12 and the short bristles 11 is within the above range, the long bristles 12 included in the second bristle bundle 8 are more likely to enter periodontal pockets and gaps between teeth, and the short bristles 11 included in the first bristle bundle 7 are more likely to contact the tooth surface, so that the tooth surface, gaps, periodontal pockets, etc. can be effectively cleaned.

[0058] The long bristles 12 included in the second bristle bundle 8 can be of various shapes known for bristles used in toothbrushes, such as flat bristles having a roughly uniform thickness over the entire length, round bristles with rounded tips, branched bristles with a portion of the tip branched, tapered bristles with at least a portion of the tip tapered, etc. From the viewpoint of smoothly entering periodontal pockets or between teeth during brushing, the long bristles 12 are preferably tapered bristles.

[0059] From the viewpoint of smoothly entering periodontal pockets or gaps between teeth during brushing, the long bristles 12 included in the second bristle bundle 8 are preferably spiral bristles twisted in the length direction as shown in Fig. 6. By having the twist in the long bristles 12, the stiffness of the long bristles 12 is increased, and the angle at which the long bristles 12 enter the periodontal pockets or gaps between teeth is stabilized. Therefore, the long bristles 12 smoothly enter the periodontal pockets or gaps between teeth.

[0060] In addition, all of the multiple long bristles 12 that mainly constitute the second bristles 8 may be spiral bristles, or the majority (for example, about 80%) of the multiple long bristles 12 included in the second bristles 8 may be spiral bristles.

[0061] The shape of the cross section (cross section perpendicular to the longitudinal direction of the bristles) of the long bristles 12 included in the second bristle bundle 8 is preferably polygonal, such as a regular square or a regular hexagon, from the viewpoint of improving the cleaning effect of the long bristles 12 when brushing teeth.

[0062] From the viewpoint of cleaning effect, the thickness of the long bristles 12 included in the second bristle bundle 8 is preferably 5 mil to 7.5 mil (0.1270 mm to 0.1905 mm), more preferably 5 mil to 6.5 mil (0.1270 mm to 0.1651 mm). In addition, the long bristles 12 having a length of 12 mm or less are shorter than the long bristles provided on a general wide toothbrush, and therefore feel harder due to loss of flexibility, and the long bristles do not contact the gums, etc., well when brushing teeth, which may cause pain to the gums, etc. Therefore, by making the thickness of the long bristles 12 6 mil or less, the long bristles 12 can gently contact the gums, etc., when brushing teeth.

[0063] The number of long bristles 12 included in the second bristle bundle 8 is preferably 25 or more and 45 or less, and more preferably 28 or more and 40 or less.

[0064] 4, the second bristle bundle 8 may include a plurality of short bristles 14 having a shorter length than the long bristles 12. In other words, the second bristle bundle 8 may be configured by bundling a plurality of long bristles 12, or may be configured by bundling a plurality of long bristles 12 and a plurality of short bristles 14.

[0065] When the second bristle bundle 8 includes the short bristles 14, the short bristles 14 support the long bristles 12, making the long bristles 12 less likely to fall over, compared to when the second bristle bundle 8 does not include the short bristles 14. This stabilizes the angle at which the long bristles 12 enter the periodontal pocket or between the teeth, making it easier for the long bristles 12, which have a long bristles length, to enter the periodontal pocket or between the teeth when brushing. This allows the long bristles 12 to effectively clean the periodontal pocket or between the teeth.

[0066] The short bristles 14 included in the second bristle bundle 8 can be of various shapes known for bristles used in toothbrushes, such as flat bristles having a roughly uniform thickness over the entire length, round bristles with rounded tips, branched bristles with a portion of the tip side branched, tapered bristles with at least a portion of the tip side tapered, etc. The short bristles 14 included in the second bristle bundle 8 may also be spiral bristles twisted in the length direction, like the long bristles 12.

[0067] The hair length of the short hairs 14 included in the second hair bundle 8 may be longer, shorter, or the same as the hair length of the short hairs 11 included in the first hair bundle 7. The difference in hair length between the long hairs 12 and the short hairs 14 included in the second hair bundle 8 is preferably 1.5 mm or more and 2.5 mm or less, more preferably 1.7 mm or more and 2.3 mm or less.

[0068] The cross-sectional shape of the short bristles 14 included in the second bristle bundle 8 is not particularly limited, but it is preferable that the cross-sectional shape is the same as that of the long bristles 12 .

[0069] The thickness of the short bristles 14 included in the second bristles 8 is not particularly limited, but it is preferable that the thickness is the same as that of the long bristles 12 .

[0070] As shown in FIG. 4, the bristles 13 for long length included in the third bristle bundle 9 are longer than the bristles 11 for short length included in the first bristle bundle 7, and preferably the same as the bristles 12 for long length included in the second bristle bundle 8. The bristles 13 for long length are preferably 9 mm or more, more preferably 10 mm or more, so that the bristles 13 can be brought into contact with the gums and cleaned well when brushing teeth. The bristles 13 for long length are 12 mm or less, which is shorter than the bristles of long length bristles provided in a general wide toothbrush, and therefore the total height of the toothbrush 1 (the thickness of the head portion 3 and the sum of the bristles 12 and 13 for long length included in the second bristle bundle 8 and the third bristle bundle 9) can be reduced. This increases the force of the toothbrush 1 to enter the oral cavity, and the toothbrush 1 can clean well even the back teeth.

[0071] The difference in bristle length between the long bristles 13 included in the third bristle bundle 9 and the short bristles 11 included in the first bristle bundle 7 is preferably greater than 1.0 mm and less than 3.0 mm, more preferably 1.5 mm or more and 2.5 mm or less. If the difference in bristle length between the long bristles 13 and the short bristles 11 is small, the long bristles 13 do not easily contact the gums when brushing teeth, and if the difference in bristle length between the long bristles 13 and the short bristles 11 is large, the short bristles 11 do not easily contact the tooth surface when brushing teeth. When the difference in bristle length between the long bristles 13 and the short bristles 11 is within the above range, the long bristles 13 included in the third bristle bundle 9 easily contact the gums when brushing teeth, and the short bristles 11 included in the first bristle bundle 7 easily contact the tooth surface, so that the tooth surface and gums can be effectively cleaned.

[0072] The long bristles 13 included in the third bristle bundle 9 can be of various shapes known for bristles used in toothbrushes, such as flat bristles having a roughly uniform thickness over the entire length, round bristles with rounded tips, branched bristles with a portion branched on the tip side, tapered bristles with at least a portion tapered on the tip side, etc. It is preferable that the long bristles 13 are tapered bristles, from the viewpoint of gently contacting the gums during brushing to prevent damage to the gums and providing a high massage effect on the gums.

[0073] The shape of the cross section (cross section perpendicular to the length direction of the hair) of the long bristles 13 included in the third bristles 9 is not particularly limited, but is preferably circular.

[0074] The thickness of the long bristles 13 included in the third bristles bundle 9 is preferably smaller than the thickness of the long bristles 12 included in the second bristles bundle 8. In other words, it is preferable that the long bristles 13 included in the third bristles bundle 9 are thinner than the long bristles 12 included in the second bristles bundle 8. This makes the long bristles 13 included in the third bristles bundle 9 softer, so that the long bristles 13 can be gently applied to the gums when they come into contact with the gums during brushing. This allows the gums to be cleaned and massaged while preventing damage to the gums.

[0075] The thickness of the long bristles 13 is preferably 4 mils to 7 mils (0.1016 mm to 0.1778 mm) and more preferably 4 mils to 6 mils (0.1016 mm to 0.1524 mm) from the viewpoint of softening the long bristles 13 and gently touching the gums when brushing teeth. The long bristles 13 are shorter than the long bristles of a typical wide toothbrush, and therefore feel harder due to loss of flexibility, which reduces the contact with the gums and the like when brushing teeth, and may cause pain to the gums and the like. Therefore, by making the thickness of the long bristles 13 6 mils or less, the long bristles 13 can gently touch the gums and the like when brushing teeth.

[0076] The number of the long bristles 13 included in the third bristle bundle 9 is preferably 30 or more and 60 or less, and more preferably 35 or more and 55 or less.

[0077] The third bristle bundle 9 may include a plurality of short bristles 15 having a shorter length than the long bristles 13. In other words, the third bristle bundle 9 may be configured by bundling a plurality of long bristles 13, or may be configured by bundling a plurality of long bristles 13 and a plurality of short bristles 15.

[0078] When the third bristle bundle 9 includes the short bristles 15, the short bristles 15 support the long bristles 13, making the long bristles 13 less likely to fall over, compared to when the third bristle bundle 9 does not include the short bristles 15. This stabilizes the angle at which the long bristles 13 come into contact with the gums, making it easier for the long bristles 13, which have a long bristles length, to come into contact with the gums when brushing the teeth. This allows the long bristles 13 to effectively clean and massage the gums.

[0079] The short bristles 15 included in the third bristle bundle 9 can be of various shapes known for use in toothbrushes, such as flat bristles having a generally uniform thickness along their entire length, round bristles with rounded tips, branched bristles with a portion of the tip that branches out, and tapered bristles whose tip is tapered by tapering at least a portion of the tip.

[0080] The hair length of the short hairs 15 included in the third hair bundle 9 may be longer, shorter, or the same as the hair length of the short hairs 11 included in the first hair bundle 7. The difference in hair length between the long hairs 13 and the short hairs 15 included in the third hair bundle 9 is preferably 1.5 mm or more and 2.5 mm or less, and more preferably 1.7 mm or more and 2.3 mm or less.

[0081] The cross-sectional shape of the short bristles 15 included in the third bristle bundle 9 is not particularly limited, but it is preferable that the cross-sectional shape is the same as that of the long bristles 13 .

[0082] The thickness of the short bristles 15 included in the third bristles 9 is not particularly limited, but it is preferable that the thickness is the same as that of the long bristles 13 .

[0083] The sum of the thickness of head portion 3 and the bristles length of long bristles 12, 13 included in second bristles 8 and third bristles 9 defines the total height of toothbrush 1. From the viewpoint of increasing the ability of toothbrush 1 to penetrate into the oral cavity, the total height of toothbrush 1 is preferably 12.0 mm or more and 16.0 mm or less, and more preferably 12.0 mm or more and 15.5 mm or less.

[0084] Furthermore, if the value obtained by dividing the thickness of the head portion 3 by the bristles length of the long bristles 12, 13 is large, the ratio of the thickness of the head portion 3 to the total height of the toothbrush 1 increases (the ratio of the bristles length of the long bristles 12, 13 decreases). As a result, the total height of the toothbrush 1 decreases, and the back teeth that are difficult to reach with the toothbrush 1 can be brushed efficiently. Therefore, the value obtained by dividing the thickness of the head portion 3 by the bristles length of the long bristles 12, 13 is 0.23 or more, and preferably 0.25 or more.

[0085] The ratio of the area occupied by the second bristle bundle 8 and the third bristle bundle 9 including the long bristles 12, 13 to the area of ​​the head portion 3 in a plan view is preferably 10% or more and less than 40%, and more preferably 10% or more and 25% or less. When the second bristle bundle 8 and the third bristle bundle 9 including the long bristles 12, 13 occupy the above-mentioned range in the head portion 3, the tooth surface, periodontal pockets, and gums can be efficiently brushed in one go.

[0086] In addition, when calculating the ratio of the area of ​​the second hair bundle 8 and the third hair bundle 9, the area of ​​the second hair bundle 8 and the third hair bundle 9 can be regarded as being the same as the area of ​​the hair transplant hole 10 in which the second hair bundle 8 and the third hair bundle 9 are implanted.

[0087] Next, the method of using the toothbrush 1 of the present embodiment described above will be described with reference to Figs. 7 and 8. The short bristles 11 included in the first bristles bundle 7 have short bristles, and are arranged in the center of the head part 3 in the horizontal direction. As shown in Fig. 7, the toothbrush 1 is inserted into the oral cavity so that the tips of the first bristles bundle 7 come into contact with the tooth surface. When the toothbrush 1 is moved vertically so that the head part 3 moves in the direction in which the teeth are arranged to brush the teeth, the tips of the second bristles bundle 8, which have longer bristles and are located outside the first bristles bundle 7 in the horizontal direction of the head part 3, enter the periodontal pocket, and the tips of the third bristles bundle 9, which have longer bristles and are located outside the second bristles bundle 8, come into contact with the gums. In addition, as shown in Fig. 8, the second bristles bundle 8, which have longer bristles and are located in front of the first bristles bundle 7 in the vertical direction of the head part 3, enter between the teeth. Therefore, when brushing the teeth, the teeth surface can be cleaned, and the gaps between the teeth, periodontal pockets, and gums can be cleaned, and the gums can be massaged.

[0088] Furthermore, when the toothbrush 1 is advanced to the back of the oral cavity, the second bristles 8, which have longer bristles and are located in front of the first bristles 7 in the longitudinal direction of the head 3, reach the molars. This allows the tooth surfaces, spaces between the teeth, periodontal pockets, and gums to be cleaned even at the molars.

[0089] When cleaning the occlusal surfaces of the teeth, the head portion 3 is held parallel to the occlusal surface, and the bristles 7-9 are pressed against the occlusal surface while brushing.

[0090] In addition, the first bristle bundles 7, which have short bristles and are arranged in the lateral center of the head unit 3, are mostly surrounded, except for a portion, by the second bristle bundles 8 and the third bristle bundles 9, which have long bristles. Therefore, when brushing teeth, the toothpaste is stirred while air is taken in inside the second bristle bundles 8 and the third bristle bundles 9, which have long bristles, so that the toothpaste is easily foamed. This makes it easier for the toothpaste to spread over a wide area, allowing for effective cleaning of the teeth.

[0091] Here, by surrounding the multiple first bristle bundles 7 with the multiple second bristle bundles 8 and the third bristle bundles 9 while forming a narrowed portion 17 at a portion close to the rear end of the multiple first bristle bundles 7, it is possible to surround more of the multiple first bristle bundles 7 with the multiple second bristle bundles 8 and the third bristle bundles 9. Therefore, the toothpaste can be satisfactorily foamed inside the multiple second bristle bundles 8 and the third bristle bundles 9 when brushing teeth.

[0092] Furthermore, if the second and third bristle bundles 8 and 9 completely surround the first bristle bundles 7, the bristle stiffness of the second and third bristle bundles 8 and 9 will be too strong, making it difficult for the tips of the first bristle bundles 7, which have a short bristle length, to reach the tooth surface when brushing the teeth, making it difficult to clean the tooth surface. On the other hand, by surrounding the first bristle bundles 7 with the second and third bristle bundles 8 and 9 except for the rearmost part around the first bristle bundles 7, the bristle stiffness of the second and third bristle bundles 8 and 9 can be appropriately reduced, so that the tips of the first bristle bundles 7, which have a short bristle length, can easily reach the tooth surface when brushing the teeth. Furthermore, since the rearmost first bristle bundle 7 of the first bristle bundles 7 is exposed from the surrounding of the second and third bristle bundles 8 and 9, the tip of the rearmost first bristle bundle 7 can easily reach the tooth surface when moving the toothbrush 1 vertically to brush the teeth. Therefore, the tips of the multiple first bristle bundles 7, starting from the rearmost first bristle bundle 7, can easily reach the tooth surface, allowing the first bristle bundles 7 to clean the tooth surface well.

[0093] In addition, when the number of first bristle bundles 7 arranged horizontally at the rearmost end of the multiple first bristle bundles 7 is one, the multiple second bristle bundles 8 and the third bristle bundles 9 can surround more of the multiple first bristle bundles 7. Therefore, the toothpaste can be satisfactorily foamed inside the multiple second bristle bundles 8 and the third bristle bundles 9 when brushing teeth.

[0094] Furthermore, if the rearmost first bristle bundle 7 of the multiple first bristle bundles 7 protrudes vertically further rearward than the second bristle bundles 8 and the third bristle bundles 9, the tip of the rearmost first bristle bundle 7 can easily reach the tooth surface when the toothbrush 1 is moved vertically to brush the teeth. Therefore, the tip of the multiple first bristle bundles 7 can more easily reach the tooth surface starting from the rearmost first bristle bundle 7, and the tooth surface can be cleaned well by the first bristle bundle 7.

[0095] Next, the action and effect of the toothbrush 1 of this embodiment will be described.

[0096] The toothbrush 1 of this embodiment is a wide toothbrush that includes multiple short bristles (first bristles 7) and multiple long bristles (second bristles 8 and third bristles 9) that are longer than the short bristles (first bristles 7), and the maximum lateral length of the head portion 3 is 15 mm or more. The toothbrush 1 of this embodiment is characterized in that in the wide toothbrush, the bristles 12, 13 included in the long bristles (second bristles 8 and third bristles 9) have a bristles length of 12 mm or less, and the value obtained by dividing the thickness of the head portion 3 by the bristles length of the long bristles 12, 13 is 0.23 or more.

[0097] According to the toothbrush 1 of this embodiment, the above-mentioned features make it possible to reduce the total height (the sum of the thickness of the head portion 3 and the length of the long bristles 12, 13) at the tip of the toothbrush 1. This increases the force with which the toothbrush 1 penetrates into the oral cavity, allowing for good cleaning even to the back teeth.

[0098] Furthermore, toothbrush 1 of the present embodiment is characterized in that long bristles 12, 13 have a thickness of 6 mils or less.

[0099] According to the toothbrush 1 of this embodiment, due to the above-mentioned characteristics, the long bristles 12, 13 are shorter than the long bristles provided on a typical wide toothbrush, and therefore, due to loss of flexibility, they feel hard and may not contact well with the gums when brushing the teeth, but because the thickness of the long bristles 12, 13 is thin, at 6 mils or less, the long bristles 12, 13 can gently contact the gums when brushing the teeth. This makes it possible to prevent damage to the gums when brushing the teeth.

[0100] Toothbrush 1 of the present embodiment is characterized in that head portion 3 has a thickness of 2.5 mm or more and 3.5 mm or less.

[0101] According to the toothbrush 1 of this embodiment, the head portion 3 is formed thin due to the above-mentioned characteristics, so that the toothbrush 1 can advance more easily into the oral cavity, and the toothbrush 1 can clean even the back teeth well. Furthermore, the head portion 3 can be easily handled in the oral cavity, improving the operability of the toothbrush 1. Furthermore, even with the head portion 3 that is wide and has a large area, discomfort felt by the user in the cheeks can be reduced.

[0102] Although one embodiment of the toothbrush of the present disclosure has been described above, the toothbrush of the present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present disclosure, including the following modifications. In addition, the gist of the following modifications can be combined as appropriate.

[0103] The number of bristle bundles 7-9 on the front surface 30 (hair implantation surface) of the head unit 3 is not particularly limited and can be changed as appropriate. The arrangement of the bristle bundles 7-9 can also be changed as appropriate, except for the arrangement required to solve the problems of the present disclosure.

[0104] The number of bristles constituting the bristles 7-9, the thickness of the bristles, and the thickness of the bristles (= the size of the bristles implantation hole 10) are not particularly limited and can be changed as appropriate.

[0105] The method of implanting each of the hair bundles 7-9 into the implantation hole 10 is not particularly limited. [Explanation of symbols]

[0106] 1 Toothbrush 2 Handle 3 Head section 7 First hair bundle (short hair bundle, inner hair bundle) 8. Second hair bundle (long hair bundle, outer hair bundle) 9. Third bundle (long bundle, outer bundle) 10. Hair transplant hole 11 Short hair 12 Long hair 13 Long hair

Claims

1. A toothbrush in which a plurality of bristles are bundled and planted in a plurality of bristles planting holes formed in a head portion, The hair brush comprises a plurality of short hair bundles and a plurality of long hair bundles including a plurality of long hair bundles having a hair length longer than that of the short hair bundles. The maximum lateral length of the head portion is 15 mm or more, The hair length of the long hair is 12 mm or less, The toothbrush has a value obtained by dividing the thickness of the head portion by the length of the long bristles of 0.23 or more.

2. 2. The toothbrush of claim 1, wherein the long bristles have a thickness of 6 mils or less.

3. 2. The toothbrush according to claim 1, wherein the thickness of the head portion is 2.5 mm or more and 3.5 mm or less.

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