Toothbrush

Abstract

Provided is a toothbrush that does not impair feeling of use while irradiating teeth with high illuminance light. This toothbrush comprises: a head portion in which a brush portion extending to one side in a first direction orthogonal to a bristle implanting surface is provided on the bristle implanting surface; a light emitting body that is provided in the head portion and emits light of a predetermined color; and an opaque portion that is provided in the head portion so as to be opened to the one side in the first direction, is formed of a first material that is light non-transmissible, and has a recess for accommodating at least a part of the light emitting body. The opaque portion reflects the light inside the recess.

Description

toothbrush

[0001] This application claims priority to Japanese Patent Application No. 2023-150063, filed on September 15, 2023, the contents of which are incorporated herein by reference.

[0002] 2. Description of the Related Art There are toothbrushes available that are equipped with light emitters such as light-emitting diodes and that can perform various functions by irradiating the oral cavity with light having a specific peak wavelength.

[0003] For example, Patent Document 1 discloses a toothbrush in which a head portion is provided with a replacement toothbrush part having a translucent resin plate with a bristle surface, and an upper cover part to which the replacement toothbrush part is attached and which has a light-emitting diode arranged inside.

[0004] Patent Document 2 discloses a toothbrush in which an emission part of an illumination device is provided at the center of the head in the width direction, and a brush is provided around the emission part.

[0005] JP 2023-61573 A JP 2004-350834 A

[0006] An example of the function of light irradiation by a light emitter is tooth whitening, which involves brushing the teeth while irradiating them with light using a toothpaste containing hydrogen peroxide or titanium oxide. In this case, it is necessary to irradiate the teeth, which are the target area, with high-intensity light, but irradiating the gums or oral cavity, which are non-target areas, with high-intensity light may be harmful.

[0007] When a light-emitting element is mounted on the head and the top of the head is covered with a light-transmitting plate having a bristled surface as in Patent Document 1, the bristles block the light, making it difficult to deliver high-intensity light to the target area, the teeth. Furthermore, the light is dispersed in various directions, resulting in the problem of reaching untargeted areas.

[0008] When the light emitter is mounted in the center of the head as in Patent Document 2, the number of light emitters that can be mounted is limited. Therefore, in Patent Document 2, the light emitter is positioned closer to the tip of the bristles than the implanted surface in order to irradiate the teeth with light of sufficient illuminance. In this case, the light emitter hinders the movement of the bristles, which causes a problem of impaired usability.

[0009] The present invention has been made in consideration of the above points, and an object of the present invention is to provide a toothbrush that can irradiate teeth with high-intensity light without impairing the feeling of use.

[0010] The present invention has the following aspects. [1] A toothbrush comprising: a head portion having a brush portion extending on one side of a bristle-implanted surface in a first direction perpendicular to the bristle-implanted surface and provided on the bristle-implanted surface; a light-emitting body provided on the head portion and emitting light of a predetermined color; and a non-transparent portion provided on the head portion with an opening on one side of the first direction, the non-transparent portion having a recess formed of a first material that is non-transparent to the light and accommodating at least a portion of the light-emitting body, wherein the non-transparent portion reflects the light inside the recess. [2] The toothbrush described in [1] above, having a transparent portion covering at least the light-emitting body exposed on one side of the first direction and formed of a second material that transmits the light, wherein at least a portion of a side of the transparent portion is surrounded by the non-transparent portion. [3] The toothbrush described in [2] above, having a grip portion extending in the longitudinal direction, wherein the transparent portion is interposed between the light-emitting body and the non-transparent portion in at least one of a cross section perpendicular to the longitudinal direction and a cross section perpendicular to a second direction perpendicular to the longitudinal direction and the first direction. [4] The toothbrush according to any one of [1] to [3], wherein the position of the light-emitting body furthest to one side in the first direction is closer to the other side in the first direction than the position of the non-transparent portion furthest to one side in the first direction. [5] The toothbrush according to [4], which includes a grip portion extending in the longitudinal direction, and wherein the recess is inclined in a direction away from the recess as it approaches one side in the first direction in at least one of a cross section perpendicular to the longitudinal direction and a cross section perpendicular to both the longitudinal direction and the first direction. [6] The toothbrush according to any one of [1] to [5], wherein, in a front view seen from the side facing the bristle surface in the first direction, the ratio of the sum of the maximum areas of one or more of the recesses to the area of ​​the head portion is 5.0% or more and 15.0% or less. [7] The toothbrush according to any one of [1] to [6], wherein the brush portion is provided in the non-transparent portion and is arranged to surround at least a portion of the periphery of the recess. [8] The toothbrush according to any one of [1] to [7], wherein the non-transparent portion has a color tone in which the R value, G value, and B value in the RGB color model are all 240 or more and 255 or less.

[0011] The present invention can provide a toothbrush that can irradiate teeth with high-intensity light without impairing the feeling of use.

[0012] FIG. 2 is a diagram showing an embodiment of the present invention, and is a front view of a toothbrush according to a first embodiment. FIG. 3 is a front view of a head portion. FIG. 4 is a cross-sectional view taken along the line A-A in FIG. 2. FIG. 5 is a front view of the head portion. FIG. 6 is a cross-sectional view of a head portion according to a second embodiment of the toothbrush. FIG. 7 is a cross-sectional view of a head portion according to a third embodiment of the toothbrush. FIG. 8 is a cross-sectional view of a head portion according to a fourth embodiment of the toothbrush. FIG. 9 is a cross-sectional view of a head portion according to a modified example of the fourth embodiment of the toothbrush. FIG. 10 is a cross-sectional view of a head portion according to a fifth embodiment of the toothbrush. FIG. 11 is a front view of a head portion according to a fifth embodiment of the toothbrush. FIG. 12 is a front view of a head portion according to a sixth embodiment of the toothbrush.

[0013] An embodiment of the toothbrush of the present invention will be described below with reference to Figures 1 to 11. 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.

[0014] 1 is a front view of a first embodiment of a toothbrush 1. The toothbrush 1 includes a grip portion 2 that is held by a user, and a brush body 3 that is detachably attached to the grip portion 2. The toothbrush 1 of this embodiment can emit light of a predetermined color from the brush body 3.

[0015] The grip portion 2 is, for example, cylindrical, and has a power switch 4 located on a portion of its outer periphery. A battery 5 serving as a power source is detachably housed inside the grip portion 2, making it replaceable. The battery 5 may be replaceable or non-replaceable. A connector portion (not shown) is provided at the detachable portion between the grip portion 2 and the brush body 3 to connect a power supply line (not shown) inside the grip portion 2 to a circuit board 30 (described later) inside the brush body 3.

[0016] The brush body 3 has a connecting base 6 , a neck 7 , a head 10 , a substrate 30 , and a light emitter 40 .

[0017] The connecting base 6, neck 7, and head 10 are made of a first material that is opaque to light L (see FIG. 3) emitted by the light emitter and reflects light L. "Opnea" is indicated by a total light transmittance of 20% or less. The total light transmittance is specified in accordance with, for example, JIS K7375:2008 "Plastics - Determination of total light transmittance and total light reflectance."

[0018] The first material may be a resin. Suitable materials for the first material include polypropylene resin (PP), polyacetal resin (POM), polystyrene resin (PS), polybutylene terephthalate resin (PBT), etc. Polycarbonate resin (PC) can also be used if it is white, since it has a total light transmittance of 10% or less. From the perspective of reflecting light L, it is preferable that the color of the light L and the color of the resin are similar.

[0019] The connecting base 6 is formed in a conical shape and is detachably attached to one end side of the grip portion 2 in the longitudinal direction. The head portion 10 is formed in a substantially elliptical shape when viewed from the front from the side opposite the tufted surface 12 described below. The head portion 10 is disposed on the other end side of the grip portion 2 in the longitudinal direction. The neck portion 7 is disposed between the connecting base 6 and the head portion 10. The neck portion 7 gradually becomes wider from the head portion 10 toward the connecting base 6 when viewed from the front. The boundary between the neck portion 7 and the head portion 10 in the longitudinal direction is the position where the width of the head portion 10 gradually narrows and then starts to widen when viewed from the front.

[0020] Fig. 2 is a front view of the head unit 10. Fig. 3 is a cross-sectional view taken along line A-A in Fig. 2. As shown in Figs. 2 and 3, the head unit 10 has a brush unit 11, a light-emitting region 41, a non-transparent unit 43, and a transparent unit 45. The brush unit 11 is provided on the bristle-implanted surface 12 of the head unit 10.

[0021] In the following description, the longitudinal direction of the grip portion 2 will be simply referred to as the longitudinal direction, the direction perpendicular to the bristle-implanted surface 12 will be referred to as the thickness direction, and the direction parallel to the bristle-implanted surface 12 and perpendicular to the longitudinal direction of the grip portion 2 will be referred to as the width direction. The thickness direction corresponds to the first direction. In addition, in the thickness direction, the side of the bristle-implanted surface 12 will be referred to as the front side, and the side opposite the bristle-implanted surface 12 will be referred to as the back side, as appropriate. The front side corresponds to one side of the first direction. The back side corresponds to the other side of the first direction. In addition, in the longitudinal direction, the side on which the brush body 3 is arranged will be referred to as the tip side, and the side on which the grip portion 2 is arranged will be referred to as the rear side.

[0022] The brush portion 11 has a plurality of bristle bundles 13. The bristle bundles 13 are implanted in bristle implantation holes 14 formed in the bristle implantation surface 12. A plurality of bristle implantation holes 14 are provided in the bristle implantation surface 12. The bristle implantation holes 14 are recesses recessed from the bristle implantation surface 12 toward the rear side. The bristle bundles 13 are implanted in the bristle implantation surface 12 by sandwiching a flat wire between two folded bristle bundles and driving the flat wire into the bristle implantation holes 14. Note that the present invention is not limited to the "flat wire type" and may also be a form in which the bristle bundles are welded together. The thickness of the head portion 10 is not particularly limited, but is preferably 5 mm or less from the viewpoint of ease of insertion into the oral cavity.

[0023] The light-emitting region 41 is provided on the front side of the head unit 10. The light-emitting region 41 is located at the center in the width direction of the head unit 10. The light-emitting region 41 is formed in a rectangular shape extending in the longitudinal direction when viewed from the front. The light-emitting region 41 is located closer to the rear end than the center in the longitudinal direction of the head unit 10.

[0024] The light-emitting region 41 has a recess 42 and a protrusion 44. The recess 42 extends in the thickness direction and opens to the front side. The recess 42 is formed in the head portion 10. That is, the recess 42 is formed in a non-transparent portion 43 made of a first material. Note that as long as the recess 42 is formed in the non-transparent portion 43 made of the first material, the head portion 10 does not necessarily have to be made of the first material; for example, the outside of the non-transparent portion 43 having the recess 42 may be made of a material different from the first material.

[0025] The non-transmitting portion 43 preferably has a color tone in which the R value, G value, and B value in the RGB color model are all 240 or more and 255 or less, and more preferably has a color tone in which the R value, G value, and B value in the RGB color model are all 250 or more and 255 or less. When the R value, G value, and B value in the RGB color model are all 240 or more and 255 or less, the non-transmitting portion 43 easily reflects and collects light L, allowing sufficient light L to reach the teeth.

[0026] The brush part 11 provided in the non-transparent part 43 is arranged to surround at least a portion of the periphery of the recess 42. In this embodiment, the brush part 11 surrounds both sides in the width direction and the tip side in the longitudinal direction of the periphery of the recess 42. By arranging the brush part 11 to surround at least a portion of the periphery of the recess 42, the light L emitted from the light emitter 40 is reflected by the bristle bundles 13, thereby improving the directivity toward the front side.

[0027] Since the light-emitting area 41 extends in the brushing direction of the brush part 11, one area can be continuously illuminated, which is efficient. From the viewpoint of continuously irradiating the teeth with blue light when brushing using the scrubbing method, which is a common brushing method, it is preferable that the light-emitting area 41 extends in the longitudinal direction and the bristle bundles 13 are arranged longitudinally along the light-emitting area 41 on both sides of the width of the light-emitting area 41. In this case, it is preferable that the ratio of the maximum width dimension of the recess 42 to the maximum width dimension of the bristle implantation area where the bristle implantation holes 14 are located in the head part 10 be 10% or more and 40% or less.

[0028] Furthermore, the arrangement of the tufting holes 14 surrounding the recess 42 is preferably a staggered arrangement in which rows of tufting holes 14 spaced at a predetermined pitch in the longitudinal direction are offset by half a pitch from adjacent rows in the width direction. By adopting this configuration, it is possible to eliminate gaps between the tufts 13 when viewed from the side in the width direction, and the directivity of the light L toward the front side can be further improved by the reflection of the tufts 13.

[0029] It is preferable that the bristles of the bristle bundle 13 have a PF (packing factor) of 70 to 90%, a bristle diameter of 5 to 8 mil, and a hole diameter of 1.4 to 1.8 mm for the bristle implantation holes 14. The PF (packing factor) means the ratio (C / B x 100%) of the total cross-sectional area C of the bristle implantation holes 14 (excluding the area B of the bristle implantation holes 14 in the case of the flat-line type, excluding the area covered by the flat line) when sliced ​​flush at the implantation surface 12 in Figure 2 and viewed from the front.

[0030] In addition, since the bristles themselves reflect light, it is preferable that the cross section of the bristles be polygonal and that the sides be aligned to form the bristles 13 and be densely packed together. Furthermore, it is preferable that the cross section of the bristles 13 be polygonal and that one side of the bristles be aligned in the longitudinal direction of the light emitter 40.

[0031] It is also preferable that the bristle bundle 13 is inclined so that it moves away from the light emitter 40 as it approaches the front side. In this case, the angle formed by the light L and the bristle bundle 13 becomes smaller, and as a result, the directivity of the head unit 10 toward the front side can be improved.

[0032] The bristles of the bristle bundle 13 preferably have a color tone in which the R value, G value, and B value in the RGB color model are all 240 or more and 255 or less, and more preferably have a color tone in which the R value, G value, and B value in the RGB color model are all 250 or more and 255 or less. When the R value, G value, and B value in the RGB color model are all 240 or more and 255 or less, the bristles are more likely to reflect light L, allowing sufficient light L to reach the teeth.

[0033] The recess 42 is formed by being recessed from the protrusion 44 toward the rear side. The protrusion 44 protrudes toward the front side from the tufting surface 12. The protrusion 44 is located at the center of the head portion 10 in the width direction.

[0034] The recess 42 accommodates at least a portion of the light emitter 40. In this embodiment, the front end of the light emitter 40 protrudes from the recess 42 toward the front. The recess 42 accommodates the rear side of the light emitter 40 relative to the end protruding toward the front. The non-transmitting portion 43 is non-transmitting to the light L emitted by the light emitter 40, and reflects the light L inside the recess 42.

[0035] When viewed from the front, the ratio of the maximum area of ​​the recesses 42 to the area of ​​the head unit 10 is preferably 5.0% or more and 15.0% or less. When multiple recesses 42 are provided, the ratio of the sum of the maximum areas of the multiple recesses 42 to the area of ​​the head unit 10 is preferably 5.0% or more and 15.0% or less. If the ratio of the maximum area of ​​the recesses 42 (or the sum if there are multiple recesses 42) to the area of ​​the head unit 10 is less than 5.0%, the illuminance of the light L reaching the teeth may be insufficient. If the ratio of the maximum area of ​​the recesses 42 (or the sum if there are multiple recesses 42) to the area of ​​the head unit 10 exceeds 15.0%, the total area of ​​the bristle implantation holes 14 where the bristle bundles 13 are provided becomes smaller, which may impair the brushing experience. Furthermore, the light L emitted from the light emitter 40 may disperse through gaps between the bristle bundles 13, potentially reaching unintended areas such as the gums.

[0036] By setting the ratio of the maximum area of ​​the recesses 42 to the area of ​​the head portion 10 to 5.0% or more and 15.0% or less, it is possible to allow light L of sufficient illuminance to reach the teeth without impairing the feeling of use during brushing. For example, when the area of ​​the head portion 10 is 250 to 500 mm in a front view, ２ In this case, the maximum area of ​​the recess 42 is 30 mm in order to allow light L of sufficient illuminance to reach the teeth. ２ can be secured.

[0037] 4 is a front view of the head unit 10. As shown in FIG. 4, the area enclosed by the dashed two-dot line connecting the outermost edges of the tufting holes 14 in the width and length directions, excluding the light-emitting regions 41, is defined as the tufting area. The ratio of the tufting area to the area of ​​the non-transparent portions 43 that make up the head unit 10 is preferably 40% or more and 80% or less. The area of ​​the non-transparent portions 43 is the area of ​​the head unit 10 including the tufting holes 14 when viewed from the front, excluding the area of ​​the transparent portions 45 exposed on the front side.

[0038] If the ratio of the bristle implantation area to the area of ​​the non-transparent portion 43 is less than 40%, the packing density of the bristle bundles 13 will be low, and the light blocking effect will not be obtained, and there is a possibility that light L will reach non-target areas such as the gums, and there is a possibility that the feel of use when brushing will be impaired.If the ratio of the bristle implantation area to the area of ​​the non-transparent portion 43 exceeds 80%, the bristles will be too dense, and there is a possibility that the feel of use when brushing will be impaired.

[0039] By setting the ratio of the bristle area to the area of ​​the non-transparent portion 43 to 40% or more and 80% or less, it is possible to allow light L of sufficient illuminance to reach the teeth while preventing light L from reaching non-target areas such as the gums, without compromising the feel of use when brushing.

[0040] The ratio of the total area of ​​the bristle holes 14 to the area of ​​the non-transmitting portions 43 is preferably 15% or more and 35% or less. If the ratio of the total area of ​​the bristle holes 14 to the area of ​​the non-transmitting portions 43 is less than 15%, the packing density of the bristle bundles 13 will be low, and the light blocking effect will not be obtained, which may allow light L to reach non-target areas such as the gums, and may impair the feel of use when brushing. If the ratio of the total area of ​​the bristle holes 14 to the area of ​​the non-transmitting portions 43 exceeds 35%, the bristles will be too dense, and the illuminance of light L reaching the teeth may be insufficient.

[0041] By setting the ratio of the total area of ​​the bristle holes 14 to the area of ​​the non-transparent portion 43 to 15% or more and 35% or less, it is possible to allow light L of sufficient illuminance to reach the teeth while preventing light L from reaching non-target areas such as the gums, without impairing the feel of use when brushing.

[0042] As shown in FIG. 2, a plurality of light emitters 40 (eight in FIG. 2) are arranged in the longitudinal direction. The light emitters 40 emit light when excited by voltage. Examples of the light emitters 40 include LEDs, laser diodes, small lamps, and semiconductor laser light sources. LEDs are preferred as the light emitters 40 because they are small, relatively inexpensive, and can easily emit light of the desired wavelength. Light emitters 40 include those that emit not only visible light, but also ultraviolet light and infrared light. It is preferable that the light emitter 40 has a peak wavelength of 400 to 700 nm.

[0043] Generally, light L attenuates inversely proportional to the square of the optical path length. In order to allow sufficient light L to reach the teeth, it is preferable that the distance from the light-emitting body 40, which is the light source, to the tip of the bristle bundle 13 is short. For example, if the light-emitting body 40 is mounted on the neck portion 7, this is not preferable because it will result in irradiation of non-target areas. By placing the light-emitting body 40 on the head portion 10, the distance to the tip of the bristle bundle 13 is shortened, which is preferable.

[0044] Furthermore, in order to irradiate sufficient light L onto target areas (e.g., teeth) and not irradiate non-target areas (e.g., gums) during brushing with the toothbrush 1, it is preferable that the light emitter 40 emits light with sufficient illuminance and that the emitted light L does not spread beyond the front side of the head unit 10. In this embodiment, by reflecting the light L emitted inside the recess 42 from the light emitter 40 by the non-transparent portion 43, it is possible to increase the illuminance of the light L that travels toward the front side and reaches the target areas (teeth).

[0045] The transmitting portion 45 covers at least the light-emitting body 40 exposed on the front side. The transmitting portion 45 is formed of a second material that transmits light L. Transmitting light L means that the total light transmittance is 70% or more. The total light transmittance is defined, for example, in accordance with the above-mentioned JIS K7375:2008 "Plastics - Determination of total light transmittance and total light reflectance."

[0046] As the second material constituting the transmitting portion 45, polyolefin resin, acrylic resin, polycarbonate resin, silicone, or the like, which has high translucency to the light L, is suitable.

[0047] The transparent portion 45 has an outer diameter larger than the outer diameter of the light emitter 40 and the inner peripheral surface of the recess 42, and is embedded from the front end face to the back side of the protrusion 44. The transparent portion 45 embedded from the front end face to the back side of the protrusion 44 covers the portion of the light emitter 40 exposed to the front side and the side surface protruding from the recess 42.

[0048] From the viewpoint of safety, taking into consideration the risk of electric shock, etc., it is necessary to avoid contact between the light-emitting body 40 and the oral cavity. Therefore, it is preferable that the portion of the light-emitting body 40 exposed on the front side is covered with the transmitting portion 45. Furthermore, the transmitting portion 45 transmits light L, so that sufficient light L can reach the teeth.

[0049] Furthermore, at least a portion of the side surface of the transmissive portion 45 is surrounded by the non-transmissive portion 43. The side surface of the transmissive portion 45 on the rear side is surrounded by the non-transmissive portion 43. By reflecting the light L emitted from the light emitter 40, which is emitted from the side surface protruding from the recess 42 and transmitted through the transmissive portion 45, at the non-transmissive portion 43, it is possible to increase the illuminance of the light L that travels toward the front side and reaches the target site (tooth).

[0050] The substrate 30 is embedded inside the brush body 3 in a non-exposed state. As shown in FIG. 2, the substrate 30 is located at the center in the width direction and extends in the longitudinal direction. As shown in FIG. 3, the substrate 30 is disposed at the bottom of the recess 42. The light emitter 40 is mounted on the front side of the substrate 30. The substrate 30 has a power supply line (not shown). When the brush body 3 is attached to the handle 2, the power supply line is connected to a connector portion provided on the handle 2. Power from the battery 5 can be supplied to the power supply line via the connector portion. The light emitter 40 emits light when current is applied. Power may be supplied from the handle 2 to the brush body 3 wirelessly.

[0051] As an example, the substrate 30 is formed from a composite substrate in which the base material is paper or glass and the resin is a combination of phenolic resin, epoxy resin, or the like. The composite substrate constituting the substrate 30 is formed from a first material that is opaque to light L and reflects light L. That is, the substrate 30 constitutes a non-transparent portion 43A. By reflecting light L emitted inside the recess 42 of the light emitter 40 by the non-transparent portion 43A, the illuminance of light L that travels toward the front side and reaches the target site (tooth) can be increased. The front side of the substrate 30 that constitutes the non-transparent portion 43A is preferably subjected to a reflective finish with high reflectivity. Examples of reflective finishes include mirror finishes.

[0052] As described above, in the toothbrush 1 of this embodiment, the non-transparent portions 43, 43A having the recess 42 that accommodates at least a portion of the light-emitting body 40 reflect light L inside the recess 42, so that high-intensity light L can be irradiated onto the teeth while preventing the user experience from being impaired.

[0053] Second Embodiment Next, a second embodiment of the toothbrush 1 will be described with reference to Fig. 5. In this figure, elements that are the same as those in the first embodiment shown in Figs. 1 to 4 are designated by the same reference numerals, and their description will be omitted.

[0054] As shown in FIG. 5 , in the toothbrush 1 of this embodiment, the frontmost position of the light-emitting body 40 is located behind the frontmost position of the non-transmitting portion 43 .

[0055] The transmitting portion 45 covers the light-emitting body 40 exposed on the front side inside the recess 42. The front end of the transmitting portion 45 protrudes from the protruding portion 44. The other configurations are the same as those of the first embodiment.

[0056] In this embodiment, in addition to obtaining the same functions and effects as those of the first embodiment, a high light-collecting effect can be obtained by reflecting light L emitted from the light emitter 40 in directions other than those perpendicular to the flocked surface 12, including the front surface of the light emitter 40, at the non-transparent portion 43. The distance in the thickness direction between the front-most position of the light emitter 40 and the front-most position of the non-transparent portion 43 is preferably 0.5 mm or more and 2.0 mm or less.

[0057] [Third Embodiment] Next, a third embodiment of the toothbrush 1 will be described with reference to Fig. 6. In this figure, the same components as those of the second embodiment shown in Fig. 5 are designated by the same reference numerals, and their description will be omitted.

[0058] 6, in the toothbrush 1 of this embodiment, the front-most position of the transparent portion 45 is the same as (flush with) the front-most position of the non-transparent portion 43. The front-most position of the transparent portion 45 is also flush with the bristle implantation surface 12. The other configurations are the same as those of the second embodiment.

[0059] If the front-most position of the transparent portion 45 is closer to the front than the front-most position of the non-transparent portion 43, the transparent portion 45 will inhibit the movement of the bristle bundle 13, resulting in a poor user experience. In this embodiment, in addition to achieving the same effects and advantages as the second embodiment, the front-most position of the transparent portion 45 is the same as the front-most position of the non-transparent portion 43, and therefore, the poor user experience can be prevented.

[0060] If the frontmost position of the transmissive portion 45 is located further back than the frontmost position of the non-transmissive portion 43, the transmissive portion 45 will be recessed, which may cause toothpaste to accumulate and inhibit the emission of light L emitted from the light emitter 40. Therefore, as long as the usability is not impaired, it is preferable that the frontmost position of the transmissive portion 45 be closer to the front than the frontmost position of the non-transmissive portion 43, as shown in FIG.

[0061] [Fourth embodiment] Next, a fourth embodiment of the toothbrush 1 will be described with reference to Fig. 7. In this figure, the same components as those of the third embodiment shown in Fig. 6 are designated by the same reference numerals, and their description will be omitted.

[0062] 7 , in the toothbrush 1 of this embodiment, the recess 42 is inclined in a direction away from the recess 42 toward the front side in at least one of a cross section perpendicular to the longitudinal direction and a cross section perpendicular to the width direction, which is orthogonal to both the longitudinal direction and the thickness direction. In this embodiment, the recess 42 is inclined in a direction away from the recess 42 toward the front side from the rear end position of the light-emitting body 40 in both a cross section perpendicular to the longitudinal direction and a cross section perpendicular to the width direction. The recess 42 may be inclined in a direction away from the recess 42 toward the front side in either a cross section perpendicular to the longitudinal direction or a cross section perpendicular to the width direction.

[0063] The transmissive portion 45 fills the space in the recess 42 other than the light emitting body 40. The other configurations are the same as those in the third embodiment.

[0064] In this embodiment, light L from the light emitter 40 is transmitted through the transmissive portions 45 throughout the entire thickness direction and is reflected by the non-transmissive portions 43. Therefore, in this embodiment, in addition to obtaining the same effects and advantages as the third embodiment, the angle formed by the light L emitted by the light emitter 40 and the inclined surface of the non-transmissive portions 43 is reduced, which increases the directivity of the light L toward the front side in the thickness direction of the head portion 10, making it possible to efficiently irradiate the light L onto the teeth.

[0065] The thickness direction position of the inclined surface of the non-transparent portion 43 may be configured to be inclined in a direction away from the recess 42 as it moves from the front end position of the light-emitting body 40 toward the front side, as shown as a modified example in Figure 8.

[0066] Fifth Embodiment Next, a fifth embodiment of the toothbrush 1 will be described with reference to Fig. 9. In this figure, the same components as those of the third embodiment shown in Fig. 6 are designated by the same reference numerals, and their description will be omitted.

[0067] 9 , in the toothbrush 1 of this embodiment, the transmissive portion 45 is provided between the light-emitting body 40 and the non-transmissive portion 43 in at least one of a cross section perpendicular to the longitudinal direction and a cross section perpendicular to the width direction. In this embodiment, the transmissive portion 45 is provided between the light-emitting body 40 and the non-transmissive portion 43 in both a cross section perpendicular to the longitudinal direction and a cross section perpendicular to the width direction. The transmissive portion 45 may also be provided between the light-emitting body 40 and the non-transmissive portion 43 in either a cross section perpendicular to the longitudinal direction or a cross section perpendicular to the width direction.

[0068] The transmissive portion 45 covers the light-emitting body 40 exposed on the front side, and also covers the light-emitting body 40 facing the non-transmissive portion 43. The other configurations are the same as those in the third embodiment.

[0069] In this embodiment, the light L emitted from the light emitter 40 in directions other than the thickness direction, which is irradiated in the longitudinal or width direction, can be reflected by the non-transparent portion 43 and irradiated onto the teeth with directionality toward the front side in the thickness direction.

[0070] The distance between the side surface of the light emitter 40 and the non-transmitting portion 43 is preferably 0.2 mm or more and 2.0 mm or less.

[0071] Preferably, the recess 42 is inclined away from the recess 42 as it moves from the rear end of the light emitter 40 toward the front, and the transmissive portion 45 is disposed between the inclined non-transmissive portion 43 and the light emitter 40. In this case, the angle formed by the light L emitted by the light emitter 40 and the inclined surface of the non-transmissive portion 43 becomes smaller, which increases the directivity of the light L toward the front side in the thickness direction of the head portion 10, making it possible to efficiently irradiate the light L onto the teeth.

[0072] 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 on design requirements, etc., without departing from the spirit of the present invention.

[0073] For example, in the above embodiment, the light emitter 40 is mounted on the front side of the substrate 30, but the present invention is not limited to this configuration. The light emitter 40 may be arranged apart from the substrate 30 without contacting the substrate 30.

[0074] Furthermore, in the above embodiment, a configuration in which one light-emitting region 41 is provided in the head unit 10 has been exemplified, but a configuration in which multiple light-emitting regions 41 (two in FIGS. 10 and 11 ) are provided in the head unit 10 may also be used, as shown as a sixth embodiment in FIGS. 10 and 11 . In the modified example shown in FIG. 10 , two light-emitting regions 41 are arranged in the center in the width direction, spaced apart in the longitudinal direction. In the modified example shown in FIG. 11 , two light-emitting regions 41 are arranged on the rear end side in the longitudinal direction, spaced apart in the width direction. As an example, each light-emitting region 41 has four light-emitting bodies 40 and is covered by a transmission portion 45.

[0075] The present invention is applicable to toothbrushes.

[0076] REFERENCE SIGNS LIST 1...toothbrush, 2...grip portion, 10...head portion, 11...brush portion, 12...bristle surface, 40...light emitting body, 42...recess, 43, 43A...non-transmitting portion, 45...transmitting portion, L...light

Claims

1. A toothbrush comprising: a head portion having a brush portion extending on one side of a bristle surface in a first direction perpendicular to the bristle surface and provided on the bristle surface; an light-emitting body provided on the head portion and emitting light of a predetermined color; and a non-transparent portion provided on the head portion with an opening on one side of the first direction, the non-transparent portion being made of a first material that is non-transparent to the light and having a recess for accommodating at least a part of the light-emitting body, wherein the non-transparent portion reflects the light on the inside of the recess.

2. The toothbrush according to claim 1, further comprising a transparent portion which covers the light-emitting element exposed on at least one side in the first direction and is made of a second material that transmits the light, and at least a portion of the side of the transparent portion is surrounded by the non-transparent portion.

3. A toothbrush as described in claim 2, comprising a grip portion extending in the longitudinal direction, wherein the transmissive portion is disposed between the light-emitting body and the non-transmissive portion in at least one of a cross section perpendicular to the longitudinal direction and a cross section perpendicular to a second direction perpendicular to the longitudinal direction and the first direction.

4. The toothbrush according to any one of claims 1 to 3, wherein the position furthest to one side in the first direction in the light-emitting body is on the other side in the first direction than the position furthest to one side in the first direction in the non-transparent portion.

5. The toothbrush according to claim 4, comprising a grip portion extending in the longitudinal direction, wherein the recess is inclined in a direction away from the recess toward one side of the first direction in at least one of a cross section perpendicular to the longitudinal direction and a cross section perpendicular to a second direction perpendicular to both the longitudinal direction and the first direction.

6. A toothbrush as claimed in any one of claims 1 to 3, wherein, when viewed from the front from the side opposite the bristle surface in the first direction, the ratio of the sum of the maximum areas of one or more of the recesses to the area of ​​the head portion is 5.0% or more and 15.0% or less.

7. The toothbrush according to any one of claims 1 to 3, wherein the brush part is provided in the non-transparent part and is arranged so as to surround at least a part of the periphery of the recess.

8. The toothbrush according to any one of claims 1 to 3, wherein the non-transparent portion has a color tone in which the R value, G value and B value in the RGB color model are all greater than or equal to 240 and less than or equal to 255.

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