toothbrush

Abstract

To provide a toothbrush capable of securing tender contact feeling to a gingiva and not damaging cleaning force and cleaning actual sensation.SOLUTION: A toothbrush comprises a plurality of bristle bundles planted on a planting plane. The plurality of bristle bundles are arranged on the planting plane, in an axial direction and in a width direction being orthogonal to the axial direction. The planting plane comprises: a center region; a first outside region arranged on one side of the center region along the width direction; and a second outside region arranged on the other side of the center region along the width direction. The plurality of bristle bundles include a first bristle bundle formed of harder bristles, and a second bristle bundle formed of softer bristles. On each of the first and second outside regions, a ratio of the second bristle bundles with respect to total sum of the first and second bristle bundles is higher than that in the center region. On the first and second outside regions, at least one first bristle bundle is arranged, and on both the ends of the axial direction, there are provided the second bristle bundles.SELECTED DRAWING: Figure 2

Description

Technical Field

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[0001] The present invention relates to a toothbrush.

Background Art

[0002] When the gums are inflamed due to periodontal abscess or the like, a toothbrush with soft bristles is preferably used to avoid damage to the gums. However, in such a toothbrush, since the bristle waist is weak, the cleaning power for removing dental plaque is insufficient, and furthermore, a sufficient feeling of cleaning cannot be obtained.

[0003] Patent Document 1 discloses a toothbrush in which tufts of harder bristles are arranged in the central region of the bristle-planting surface of the head portion of the toothbrush, and tufts of softer bristles are arranged in the regions outside the central region in the left-right direction. According to this toothbrush, while ensuring the massage effect on the tooth surface and gums with the outer tuft row, the cleaning power is ensured with the inner tuft row.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the toothbrush of Patent Document 1, when the outer tuft row is moved along the tooth surface or gums so as to slide, since the outer tuft row is soft, it will fall along the sliding direction. Even if a gentle touch on the gums can be ensured by the outer tuft row, the cleaning power will decrease because the tuft row does not firmly contact the tooth surface or gums, and furthermore, the feeling of cleaning may be impaired.

[0006] An object of the present invention is to provide a toothbrush that ensures a gentle touch on the gums while not impairing the cleaning power or the feeling of cleaning. [Means for solving the problem]

[0007] A toothbrush according to a first aspect of the present invention comprises a rod-shaped handle portion, a head portion connected to the axial end of the handle portion and having a bristle-planted surface, and a plurality of bristle bundles planted on the bristle-planted surface, The plurality of hair bundles are arranged on the bristle surface in the axial direction and in the width direction perpendicular to the axial direction. The bristle surface includes a central region, a first outer region located on one side of the central region along the width direction, and a second outer region located on the other side of the central region along the width direction. The plurality of hair bundles include a first hair bundle made of stiffer hairs and a second hair bundle made of softer hairs. In both the first and second outer regions, the ratio of the second hair bundle to the sum of the first and second hair bundles is higher than in the central region. In both the first and second outer regions, at least one first hair bundle is arranged, and the second hair bundles are arranged at both ends in the axial direction.

[0008] A toothbrush according to a second aspect of the present invention is a toothbrush according to a first aspect, wherein in both the first outer region and the second outer region, the ratio of the first bristle bundle to the sum of the first and second bristle bundles is 50% or less.

[0009] A toothbrush according to a third aspect of the present invention is a toothbrush according to the first or second aspect, wherein in both the first outer region and the second outer region, the first bristle bundle is positioned in the central part in the axial direction.

[0010] A toothbrush according to the fourth aspect of the present invention is a toothbrush according to any of the first or third aspects, wherein in both the first outer region and the second outer region, at least two rows of bristle bundles are arranged, and these at least two rows of bristle bundles are arranged in the width direction and each consists of a plurality of bristle bundles arranged in the axial direction.

[0011] A toothbrush according to the fifth aspect of the present invention is a toothbrush according to the fourth aspect, wherein in both the first outer region and the second outer region, the outermost row of bristle bundles in the width direction does not include the first bristle bundle.

[0012] A toothbrush according to the sixth aspect of the present invention is a toothbrush according to any of the first or fifth aspects, wherein in both the first outer region and the second outer region, only two rows of bristle bundles are arranged, and these two rows of bristle bundles are aligned in the width direction and each consists of a plurality of bristle bundles aligned in the axial direction.

[0013] A toothbrush according to the seventh aspect of the present invention is a toothbrush according to any of the first or sixth aspects, wherein in both the first outer region and the second outer region, only one of the first bristle bundles is arranged. [Effects of the Invention]

[0014] From the above perspective, the bristle surface is implanted with a first bristle bundle consisting of stiffer bristles and a second bristle bundle consisting of softer bristles. Furthermore, in the widthwise direction of the bristle surface, in both the outer regions (first outer region and second outer region), the ratio of the second bristle bundle to the sum of the first and second bristle bundles is higher than in the central region. Therefore, the bristle bundles in the outer regions are generally composed of relatively soft bristles. In addition, second bristle bundles are positioned at both ends in the axial direction of the outer regions. Thus, when brushing by sliding the bristle bundles in the outer regions along the tooth surface (including the cervical area; the same applies hereinafter), the softer second bristle bundles located at the leading end in the sliding direction first gently contact the tooth surface and gums. As a result, the entire bristle bundle then begins to slide smoothly. Therefore, excessive force is not applied to the gums during such brushing. In addition, at least one stiffer first bristle bundle is positioned in both the first and second outer regions. As a result, when brushing, the bristle rows in the outer region slide along the tooth surface and gums, the harder first bristle row provides resistance, making it less likely for the softer second bristle row to bend in the sliding direction, thus making it easier to maintain an upright position. Therefore, the bristle rows in the outer region can thoroughly clean the tooth surface and gums. In summary, this provides a toothbrush that ensures a gentle feel against the gums while not compromising cleaning power or the feeling of thorough cleaning. [Brief explanation of the drawing]

[0015] [Figure 1] A perspective view of a toothbrush according to one embodiment of the present invention. [Figure 2] A plan view of the head portion of the toothbrush shown in Figure 1 and the multiple bristle bundles attached thereto. [Figure 3] Side view of Figure 2. [Figure 4] Front view of Figure 2. [Figure 5] Side view of a single hair within a hair bundle. [Figure 6A] A plan view of the head portion and the multiple bristles attached thereto in a modified example. [Figure 6B]Plan view of the head part according to another modification example and a plurality of tufts of bristles attached thereto. [Figure 6C] Plan view of the head part according to yet another modification example and a plurality of tufts of bristles attached thereto. [Figure 6D] Plan view of the head part according to yet another modification example and a plurality of tufts of bristles attached thereto. [Figure 6E] Plan view of the head part according to yet another modification example and a plurality of tufts of bristles attached thereto.

Mode for Carrying Out the Invention

[0016] Hereinafter, a toothbrush according to an embodiment of the present invention will be described with reference to the drawings.

[0017] <1. Overview of the Toothbrush> As shown in FIG. 1, the toothbrush 100 according to the present embodiment includes a rod-shaped handle portion 1, a head portion 2 connected to the axial front end portion of the handle portion 1, and a plurality of tufts of bristles 3 implanted on the bristle-implanted surface A1 of the head portion 2. Unless otherwise specified, in the description of this specification, front and rear, left and right, and up and down are defined as shown in FIGS. 1 and 2. The front-rear direction coincides with the axial direction of the handle portion 1, the front end side to which the head portion 2 is connected is "front", and the opposite side is "rear". The left-right direction is parallel to the bristle-implanted surface A1 and perpendicular to the axial direction of the handle portion 1. The left side toward the bristle-implanted surface A1 is "left", and the right side is "right". The up-down direction is perpendicular to the front-rear direction and the left-right direction. The root side of the tuft of bristles 3 is "down", and the tip side of the tuft of bristles 3 is "up". Hereinafter, each part 1, 2, and 3 will be described in detail.

[0018] <1-1. Handle Portion> The handle portion 1 comprises a rod-shaped base portion 11 for the user to grip with their hand, and a connecting portion 12 that connects the base portion 11 and the head portion 2. These portions 11 and 12 are integrally formed. The connecting portion 12 is formed in a rod shape that is thinner than the base portion 11. The upper, lower, and side surfaces of the tip of the base portion 11 are formed with resting portions 13 for the user to place their fingers on. The resting portions 13 can be formed with a bumpy surface to provide a non-slip effect for the fingers, and rubber or the like can be placed in this portion.

[0019] The material of the handle portion 1 is not particularly limited, but typically it can be made of synthetic resin, except for the portion where the rubber or the like described above is placed.

[0020] <1-2. Head section> Figure 2 is a plan view of the head portion 2 and the multiple bristle bundles 3 attached thereto, Figure 3 is a side view thereof, and Figure 4 is a front view thereof. As shown in these figures, the head portion 2 is formed in a thin plate shape in the vertical direction and has a bristle surface A1 on its upper side. In this embodiment, the bristle surface A1 is substantially planar. The bristle surface A1, which is the upper surface of the head portion 2, has a roughly octagonal shape that is long in the front-to-back direction. The contour of the bristle surface A1 has a tip edge 21, a first right edge 22, a first left edge 23, a second right edge 24, a second left edge 25, a third right edge 26, and a third left edge 27.

[0021] The tip edge 21 is the shortest edge of the head portion 2, and is slightly rounded, extending in the left-right direction. The first right edge 22 and the first left edge 23 are connected to both ends of the tip edge 21, respectively, and these edges 22 and 23 extend apart from each other as they move backward from the tip edge 21. The second right edge 24 and the second left edge 25 are connected to the rear ends of the first right edge 22 and the first left edge 23, respectively, and extend parallel to each other and parallel in the front-rear direction. The third right edge 26 and the third left edge 27 are connected to the rear ends of the second right edge 24 and the second left edge 25, respectively. These edges 27 and 26 extend closer to each other as they move backward, and are connected to both ends in the left-right direction of the tip of the handle portion 1, respectively.

[0022] As described above, the fuzzy surface A1 has a roughly rectangular central region A11, a roughly trapezoidal front region A12 adjacent to the front side of the central region A11, and a roughly inverted trapezoidal rear region A13 adjacent to the rear side of the central region A11. Furthermore, when the fuzzy surface A1 is divided from another perspective, it includes a central region A21 in the left-right direction, a first outer region A22 located on one side of the central region A21 along the left-right direction, and a second outer region A23 located on the other side of the central region A21 along the left-right direction. In Figure 2, the boundaries of these regions A21 to A23 are shown by dashed lines. The first outer region A22 is adjacent to the left side of the central region A21 and touches the left edge of the fuzzy surface A1. The second outer region A23 is adjacent to the right side of the central region A21 and touches the right edge of the fuzzy surface A1.

[0023] Multiple hair flocking holes 28 are formed on the hair flocking surface A1 of the head portion 2, into which hair bundles 3 are implanted (see Figure 3). In the side view of Figure 3, the hair flocking holes 28 are not normally visible, but for convenience, their positions are indicated by dotted lines in the figure. The hair flocking holes 28 are arranged in the front-to-back and left-to-right directions on the hair flocking surface A1. The shape of the hair flocking holes 28 is not particularly limited and can be, for example, a perfect circle, an ellipse, a polygon, etc. In this embodiment, the shape and diameter of the multiple hair flocking holes 28 on the hair flocking surface A1 are all substantially the same. The diameter of each hair flocking hole 28 can be, for example, 0.5 mm to 2 mm. The shape of the hair flocking hole 28 referred to here is the shape in a plan view, and the diameter of the hair flocking hole 28 referred to here is the maximum diameter of the outline of the hair flocking hole 28 in a plan view.

[0024] The width W of the head portion 2 is not particularly limited as long as it does not cause any problems in handling the head portion 2 in the oral cavity, but is preferably 10 mm to 20 mm, more preferably 13 mm to 17 mm, and even more preferably 14 mm to 16 mm. The larger the width W of the head portion 2, the more rows of bristle bundles can be planted in the left-right direction on the bristle surface A1, allowing for cleaning of a larger area at once. For example, it is possible to arrange five or more rows of bristle bundles 3 in the left-right direction on the bristle surface A1, more preferably six or more rows. The width of the head portion 2 refers to the maximum width of the head portion 2 in the left-right direction, and in this embodiment, it corresponds to the distance between the second right side 24 and the second left side 25.

[0025] The material of the head portion 2 is not particularly limited, but it can typically be made of synthetic resin. The head portion 2 can be integrally formed from the same material as the handle portion 1.

[0026] <1-3. Hair bundles> Multiple hair bundles 3 are implanted on the hair implantation surface A1 of the head portion 2. Each hair bundle 3 is a collection of many individual hairs. These hair bundles 3 are implanted one bundle each into multiple hair implantation holes 28 on the hair implantation surface A1.

[0027] As shown in Figure 2, on the hair implantation surface A1, multiple hair bundles 3 are arranged in a two-dimensional manner in the front-to-back and left-to-right directions, thereby forming multiple rows of hair bundles aligned in the left-to-right direction. Here, "row" refers to a row of elements aligned in the front-to-back direction, and each row of hair bundles consists of multiple hair bundles 3 aligned in the front-to-back direction. Note that the rows of hair bundles are not necessarily in a straight line in the front-to-back direction, and include anything that can be visually recognized as a row.

[0028] In this embodiment, as shown in Figure 2, six rows of hair bundles are arranged on the hair implantation surface A1. More specifically, in the central region A21 in the left-right direction of the hair implantation surface A1, two rows of hair bundles (hereinafter sometimes referred to as inner hair bundles) L1 extend in the front-to-back direction. In addition, another row of hair bundles (hereinafter sometimes referred to as intermediate hair bundles) L2 extends in the front-to-back direction, flanking these two rows of inner hair bundles L1 from both sides in the left-right direction. The intermediate hair bundles L2 consist of two rows, one on each side of the inner hair bundles L1. Furthermore, another row of hair bundles (hereinafter referred to as outer hair bundles) L3 extends in the front-to-back direction, flanking these two rows of intermediate hair bundles L2 from both sides in the left-right direction. The outer hair bundles L3 consist of two rows, one on each side of the intermediate hair bundles L2. The outer hair bundles L3 are located furthest to the left in the left-right direction among all the hair bundles. Therefore, the two rows of outer hair bundles L3 extend along the second right side 24 and the second left side 25, respectively, in their vicinity. The first outer region A22 has one row each of intermediate hair bundles L2 and outer hair bundles L3, and the second outer region A23 also has one row each of intermediate hair bundles L2 and outer hair bundles L3.

[0029] In this embodiment, as described above, since the bristle-implanted surface A1 is a roughly octagonal shape that is long in the front-to-back direction, the inner bristle bundle row L1 and the intermediate bristle bundle row L2 do not extend parallel to the front-to-back direction along their entire length. More specifically, on the bristle-implanted surface A1, in the roughly rectangular central region A11, the inner bristle bundle row L1, the intermediate bristle bundle row L2, and the outer bristle bundle row L3 all extend parallel to the front-to-back direction. However, in the front region A12, the inner bristle bundle row L1 and the intermediate bristle bundle row L2 are bent outward in the left-to-right direction from the front end of the central region A11, and in the rear region A13, they are shifted outward in the left-to-right direction from the rear end of the central region A11. Furthermore, in this way, multiple other bristle bundles 3 are arranged in the gaps between the two rows of inner bristle bundle rows L1 formed in the front region A12 and the rear region A13 to fill the gaps.

[0030] Figure 5 is a side view of a single bristle included in the bristle bundle 3. As shown in the figure, in this embodiment, each bristle planted on the bristle surface A1 has a tip (upper end) 32 composed of multiple branched bristles. That is, each bristle included in the bristle bundle 3 has a single base 31 that stands upright from the bristle surface A1, and a tip 32 consisting of multiple branched bristles that branch out from the upper end of the base 31. Although not limited to this, the number of branched bristles branching from the single base 31 is typically 2 to 7, and more preferably 3 to 5. Since each branched bristles at the tip 32 is thinner than the base 31, they can get into narrow gaps such as between teeth and in periodontal pockets, thereby increasing the cleaning power in the mouth. In addition, when the tip 32 has a structure with many branched bristles, the surface area of ​​the bristles that come into contact with the tooth surface is larger compared to when they are not branched, thus increasing the cleaning power. Furthermore, the branched bristles can also have the function of holding toothpaste.

[0031] In this embodiment, the length H of all hairs implanted on the hair implantation surface A1 is generally uniform. However, some variation exists. The hair length H is not particularly limited, but its average value is preferably 8 mm to 13 mm, more preferably 9 mm to 13 mm, and even more preferably 10 mm to 12 mm. Note that the hair length H is the length from the hair implantation surface A1 to the tip of the hair.

[0032] The hair bundles 3 implanted on the hair implantation surface A1 include multiple types of hair bundles. In this embodiment, hair bundles 3 include two types of hair bundles, more specifically, a first hair bundle 3a which is a stiffer hair bundle and a second hair bundle 3b which is a softer hair bundle. In Figure 2, the first hair bundle 3a is shown in white, and the second hair bundle 3b is shown in a darker color. The same applies to Figures 6A to 6E, which will be described later. However, this is for the sake of explanation, and in reality, all hair bundles can be colored the same color, or they can be colored differently depending on the type of hair bundle, as shown in Figures 2 and 6A to 6E.

[0033] In this context, "hard" refers to bristles with strong stiffness, and the first bristle bundle 3a can effectively remove plaque and other oral debris when it comes into contact with the teeth and gums. On the other hand, "soft" refers to bristles with weak stiffness, and the second bristle bundle 3b can provide a gentle touch when it comes into contact with the teeth and gums. In other words, the first bristle bundle 3a contributes to enhancing the cleaning power and the feeling of cleaning during brushing. Meanwhile, the second bristle bundle 3b has a high gum massage effect, which helps to avoid gum damage during brushing.

[0034] In this embodiment, each bristle in the second bristle bundle 3b is thinner than each bristle in the first bristle bundle 3a. The diameter of each bristle in the second bristle bundle 3b is not particularly limited as long as it can exhibit the massage effect described above, but is preferably 3 mil (0.0762 mm) to 7 mil (0.1778 mm), and more preferably 4 mil (0.1016 mm) to 6 mil (0.1524 mm). On the other hand, the diameter of each bristle in the first bristle bundle 3a is not particularly limited as long as sufficient cleaning power and a sense of cleaning can be obtained, but is preferably 4 mil (0.1016 mm) to 10 mil (0.254 mm), and more preferably 5 mil (0.127 mm) to 9 mil (0.2286 mm). The bristles used in toothbrush 100 include various types, such as branched bristles with a branched tip 32 as described above, flat bristles with a generally uniform diameter along their entire length, tapered bristles that become thinner towards the tip, and rounded bristles with a rounded tip. However, the bristle diameter referred to here is the diameter measured at the base of the bristle. Furthermore, the bristle diameter referred to here is the maximum diameter of the cross-section perpendicular to the longitudinal direction of the bristle.

[0035] In this embodiment, the number of hairs per bundle in the second hair bundle 3b is greater than the number of hairs per bundle in the first hair bundle 3a. The number of hairs per bundle in the second hair bundle 3b is not particularly limited, but is preferably 60 to 200, and more preferably 80 to 120. The number of hairs per bundle in the first hair bundle 3a is also not particularly limited, but is preferably 40 to 150, and more preferably 60 to 100. The number of hairs per bundle referred to here is the number of hairs per bundle that protrude from the hair implantation surface A1.

[0036] As shown in Figure 2, in this embodiment, the inner hair bundle row L1 located in the central region A21 in the left-right direction on the hair implantation surface A1 does not include the second hair bundle 3b, but only the first hair bundle 3a. Similarly, all the hair bundles 3 located between the two rows of inner hair bundle rows L1 in the front region A12 and the rear region A13 are also first hair bundles 3a. On the other hand, the outer hair bundle row L3 located on the outermost side in the left-right direction on the hair implantation surface A1 does not include the first hair bundle 3a, but only the second hair bundle 3b. Furthermore, the intermediate hair bundle row L2 sandwiched between the inner hair bundle row L1 and the outer hair bundle row L3 contains a small amount of first hair bundle 3a, but is mainly composed of second hair bundles 3b. More specifically, each intermediate hair bundle row L2 includes one first hair bundle 3a in the center in the front-back direction, and second hair bundles 3b arranged to sandwich this first hair bundle 3a from both sides in the front-back direction. Within each intermediate hair bundle row L2, the second hair bundle 3b is arranged in a total of six units, three in front of and three behind the first hair bundle 3a, and is positioned on the outermost side along the front-to-back direction.

[0037] With the first hair bundle 3a and the second hair bundle 3b arranged as described above, in this embodiment, in both the first outer region A22 and the second outer region A23, one first hair bundle 3a is placed, and furthermore, this first hair bundle 3a is placed in the center in the front-to-back direction. In addition, in both the first outer region A22 and the second outer region A23, the second hair bundle 3b is placed at both ends in the front-to-back direction. Furthermore, in both the first outer region A22 and the second outer region A23, the ratio of the number of second hair bundles 3b to the sum of the number of first hair bundles 3a and second hair bundles 3b (hereinafter referred to as the second hair bundle ratio) is higher than in the central region A21. Also, the second hair bundle ratio increases in the order of inner hair bundle row L1, intermediate hair bundle row L2, and outer hair bundle row L3. Therefore, the inner hair bundles 3 in the left-to-right direction are hard, and the outer hair bundles 3 in the left-to-right direction are soft.

[0038] Here, the ratio of the number of first hair bundles 3a to the total number of first hair bundles 3a and second hair bundles 3b is defined as the first hair bundle ratio. In this case, the first hair bundle ratio in both the first outer region A22 and the second outer region A23 is preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, and particularly preferably 20% or less. On the other hand, the first hair bundle ratio in the central region A21 is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, particularly preferably 90% or more, and most preferably 95% or more.

[0039] The material that makes up the hair of the hair bundle 3 is not particularly limited, but can be saturated polyester resin, nylon, etc.

[0040] <2. How to use a toothbrush> The usage instructions for the toothbrush 100, which is configured as described above, are explained below.

[0041] First, let's consider how to brush the occlusal surface of the teeth. When brushing the occlusal surface, slide the toothbrush 100 back and forth while applying the entire upper surface of bristle bundle 3 to the occlusal surface. This ensures that the inner bristle bundle row L1, located in the central region A21 in the left-right direction, makes firm contact with the occlusal surface. At this time, the inner bristle bundle row L1, consisting only of the first bristle bundle 3a, is relatively hard and has high cleaning power, so it can effectively remove plaque and other dirt attached to the occlusal surface. At this time, you can also get a good sense of thorough cleaning.

[0042] Next, let's consider cleaning the tooth surface. When cleaning the tooth surface, the toothbrush 100 is slid back and forth while applying the entire side of the bristle bundle 3 to the tooth surface and gums. This causes the bristle bundle rows L2 and L3, which are included in the first outer region A22 or the second outer region A23, and especially the outer bristle bundle row L3, which is located furthest out in the left-right direction, to come into contact with the tooth surface and gums. At this time, the outer bristle bundle row L3, which consists only of the second bristle bundle 3b, is relatively soft and therefore makes gentle contact with the gums. Also, the intermediate bristle bundle row L2, which is adjacent to the inside of the outer bristle bundle row L3 in the left-right direction, also mainly includes the second bristle bundle 3b and is therefore relatively soft, though not as soft as the outer bristle bundle row L3. Thus, the entire bristle bundle 3 included in the first outer region A22 or the second outer region A23 can be used to brush the tooth surface and gums as if gently massaging them.

[0043] Furthermore, when brushing with bristle rows L2 and L3, which are included in the first outer region A22 or the second outer region A23, sliding along the tooth surface and gums (hereinafter, this type of brushing may be referred to as lateral brushing), the softer second bristle 3b, located at the tip in the sliding direction within bristle rows L2 and L3, first gently contacts the tooth surface and gums. As a result, the entire bristle rows L2 and L3 then begin to slide smoothly. Therefore, excessive force is not applied to the gums during lateral brushing. Thus, during lateral brushing, it is possible to clean the gums and tooth surface as if massaging them, while being gentle on and protecting the gums. In addition, during lateral brushing, the tip 32 of the outer bristle row L3 can enter the periodontal pocket and scrape out dirt.

[0044] As mentioned above, the intermediate bristle rows L2 of both the first outer region A22 and the second outer region A23 each contain a harder first bristle 3a at positions other than their front-to-back ends. Therefore, during lateral brushing, this first bristle 3a provides resistance, making it more difficult for the second bristle 3b, which is included in the intermediate bristle row L2 and sandwiches the first bristle 3a, to tilt in the sliding direction, thus making it easier to maintain an upright position. Furthermore, as the intermediate bristle row L2 moves in this way, the second bristle 3b included in the outer bristle row L3 also becomes easier to maintain an upright position. Therefore, the outer bristle row L3 and the intermediate bristle row L2 can thoroughly clean the tooth surface and gums. In summary, toothbrush 100 ensures a gentle feel against the gums while maintaining both cleaning power and a sense of cleanliness.

[0045] <3. Variant> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention. The gist of the following modifications can be combined as appropriate.

[0046] <3-1> The number of hair bundle rows included in the central region A21, the first outer region A22, and the second outer region A23 is not limited to those described above. For example, the central region A21 may contain only one hair bundle row, or it may contain three or more rows. Similarly, the first outer region A22 may contain only one hair bundle row, or it may contain three or more rows. Similarly, the second outer region A23 may contain only one hair bundle row, or it may contain three or more rows. However, it is preferable that the same number of hair bundle rows are arranged in the first outer region A22 and the second outer region A23.

[0047] <3-2> In the above embodiment, all the hairs implanted on the hair implantation surface A1 had a branched structure at the tip 32 consisting of multiple branched hairs. However, the hairs implanted on the hair implantation surface A1 are not limited to hairs with a branched structure; for example, they may be flat hairs, tapered hairs, round hairs, etc., as described above, or multiple types of hair may be mixed and used from among these various types. In this case, different types of hair may be mixed in one hair bundle, or the same type of hair may be used in one hair bundle, while different types of hair may be used in different hair bundles.

[0048] <3-3> The arrangement of the first hair bundles 3a and the second hair bundles 3b in the central region A21, the first outer region A22, and the second outer region A23 is not limited to those described above. For example, the intermediate hair bundle row L2 included in the first outer region A22 and the second outer region A23 may contain multiple first hair bundles 3a, as shown in Figures 6A and 6B. Also, as shown in Figure 6C, the outer hair bundle row L3 may contain first hair bundles 3a. In particular, as in the example in Figure 6C, it is preferable that the first hair bundles 3a included in the outer hair bundle row L3 are located in the center in the front-to-back direction, and also preferably arranged adjacent to the left and right of the first hair bundles 3a included in the intermediate hair bundle row L2. Also, as shown in Figures 6D and 6E, the inner hair bundle row L1 may contain a small amount of second hair bundles 3b.

[0049] In the first outer region A22 and the second outer region A23, multiple first bristle bundles 3a may be arranged adjacent to each other in the front-to-back direction, but it is preferable that they are not arranged adjacent to each other in the front-to-back direction, as shown in the examples in Figures 2 and 6A to 6E. In the latter case, when brushing the sides, the second bristle bundle 3b is less likely to bend due to the presence of the first bristle bundle 3a, improving the feeling of cleaning. [Explanation of Symbols]

[0050] 100 toothbrushes 1. Handle section 2 Head section 3 strands of hair 3a First hair bundle 3b 2nd hair bundle 31 Base 32 Tip A1 Hair implantation surface L1 Inner hair bundle row L2 Intermediate hair bundle row L3 Outer hair bundle row

Claims

1. A rod-shaped handle section, A head portion having a bristle surface is connected to the axial end of the handle portion, Multiple bundles of hair implanted on the aforementioned hair-implanted surface, Equipped with, The head portion has a shape that extends in the axial direction, The plurality of hair bundles are arranged on the hair implantation surface in the axial direction and in the width direction perpendicular to the axial direction. The bristled surface includes a central region, a first outer region located on one side of the central region along the width direction, and a second outer region located on the other side of the central region along the width direction. The aforementioned plurality of hair bundles include a first hair bundle made of stiff hair and a second hair bundle made of softer hair than the stiff hair. The first hair bundle is harder than the second hair bundle. In both the first outer region and the second outer region, only two rows of hair bundles are arranged, and these two rows of hair bundles are aligned in the width direction and each is composed of multiple hair bundles aligned in the axial direction. In both the first outer region and the second outer region, the ratio of the second hair bundle to the sum of the first and second hair bundles is higher than in the central region. In both the first outer region and the second outer region, at least one of the first hair bundles is arranged, and the second hair bundles are arranged at both ends in the axial direction. In both the first outer region and the second outer region, the ratio of the first hair bundle to the sum of the first and second hair bundles is 30% or less. The lengths of the multiple hair bundles implanted on the aforementioned hair implantation surface are substantially equal. toothbrush.

2. The number of hairs per bundle in the second bundle is greater than the number of hairs per bundle in the first bundle. The toothbrush according to claim 1.

3. In both the first outer region and the second outer region, the first hair bundle is positioned in the central part in the axial direction. The toothbrush according to claim 1 or 2.

4. In both the first outer region and the second outer region, only one of the first hair bundles is arranged. A toothbrush according to any one of claims 1 to 3.

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