Patent ID: 12257030

DETAILED DESCRIPTION

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top,” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the exemplified embodiments. Accordingly, the invention expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.

As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.

Referring toFIGS.1and2concurrently, an electric toothbrush10a(also referred to herein as an oral care implement or a powered toothbrush in some embodiments) is shown in accordance with an embodiment of the present invention.FIG.1is a planar view illustrating a schematic configuration of the electric toothbrush10aviewed from the brush pressing direction (the direction that a user presses onto tooth cleaning elements during use), andFIG.2is a cross-sectional view taken along line A-A ofFIG.1.

The electric toothbrush10aincludes a gripping part11that includes a battery and an electric control system therein, as well as a main body having a stem12fixed to the gripping part11, and a brush unit20that can be detached from the stem12. The stem12extends from the gripping part11and forms the portion of the electric toothbrush10ato which the brush unit20may be coupled. Specifically, the brush unit20includes an interior cavity43that permits the brush unit20to be coupled to the stem12by inserting the stem12into the interior cavity43. The brush unit20may be repetitively coupled to and detached from the stem12as necessary or desired. The brush unit20and the stem12may also include corresponding structures that facilitate locking the brush unit20to the stem12(a boss and a corresponding notch, an indent and a corresponding detent, or the like). Thus, the gripping part11and the stem12may be reused with different brush units20having different structural arrangements to achieve different purposes. Furthermore, the brush unit20may be replaced when the tooth cleaning elements thereon are worn or splayed over time. This saves a user costs because the portion of the electric toothbrush10athat includes the circuitry may be reused while the brush unit20which is a simple and cheap component may be replaced. The brush unit20may be referred to herein and in the art as a refill head.

The brush unit20includes a front surface41and an opposite rear surface42. Furthermore, the brush unit20includes a plurality of tooth cleaning elements22extending from the front surface41. The plurality of tooth cleaning elements22are depicted in various aligned columns and rows, although the invention is not to be so limited. The number, pattern, configuration, and structure of the tooth cleaning elements22is not to be limited in all embodiments. In certain embodiments, the tooth cleaning elements22are formed by a plurality of bristles that are bundled together into tufts that are then coupled to a head of the brush unit20. The tooth cleaning elements22may be coupled to the head using staple technology, anchor-free tufting technologies, in-mold tufting technologies, or any other technology now known or later discovered. The tooth cleaning elements22may include bristles alone, bristles in combination with lamella formed of an elastomeric material, only bristles formed of an elastomeric material, or the like. The invention is not to be particularly limited by the specific details of the bristles unless specifically claimed as such. As discussed above, in certain embodiments the brush unit20may be detachable from the stem12and replaceable as needed when the tooth cleaning elements22thereon become frayed from use.

The brush unit20is also includes a light transmitting part23and a light receiving part24. The light transmitting part23and the light receiving part24are formed on the front surface41of the brush unit20. InFIG.1, the brush unit20is viewed from a position above the front surface41, and the direction in which the tooth cleaning elements22extend away from the front surface41is referred to herein as the “pressing direction” of the tooth cleaning elements22. As illustrated inFIG.1, the tooth cleaning elements22are arranged in an “H” shape. The outer edge21“H” shaped arrangement of the tooth cleaning elements22is formed to include a first recess21aand a second recess21b, each of which is respectively included on one of the short sides of the “H” shape. The light transmitting part23is positioned within the recess21a, and the light receiving part24is positioned on the recess21b.

The light transmitting part23is a first transparent window formed by a first transmission member44fit into a hole45formed in the front surface41of the brush unit20. As described below, the first transmission member44transmits light emitted from a light emitting element17included as part of the stem12. Light emitted from the light emitting element17is thereby transmitted to the exterior of the brush unit20through the light transmitting part23. Similarly, the light receiving part24is a second transparent window formed by a second transmission member46fit into a hole47in the front surface41of the brush unit20. As described below, the second transmission member46transmits light emitted from the light transmitting part23and reflected or received from a target object in the mouth (e.g., a tooth). Light that transmits through the second transmission member46is incident on a light sensing element18included as part of the stem12.

As shown in the exemplified embodiment, the light transmitting part23and the light receiving part24are arranged outside the edges of the “H” shape formed by the tooth cleaning elements22, such that at least a first group48of tooth cleaning elements22are positioned between the light transmitting part23and the light receiving part24. Both the light transmitting part23and the light receiving part24also lie on a line which is parallel to the longitudinal dimension of the brush unit20, however, the invention is not to be so limited unless otherwise stated in the claims. More generally, with regards to the positioning of the light transmitting part23and the light receiving part24, the tooth cleaning elements22form a bristle field, and both the light transmitting part23and the light receiving part24are located external to the bristle field on the front surface41of the brush unit20. In certain embodiments, one or both of the light transmitting part23and the light receiving part24may be located within the field of tooth cleaning elements22, or at any other desired location along front surface41the brush unit20, to the extent that the tooth cleaning elements22are configured to not interfere with the emitted light. Thus, the invention is not to be particularly limited by the position of the transparent window23unless specifically claimed as such.

As is shown inFIG.2, the brush unit20includes a cylindrical housing50with the tip end portion51being closed to form a hollow part20a. The stem12includes a tube shaped housing52with the tip end53closed. By fitting the stem12into the hollow part20a, the main body unit and the brush unit20may be coupled together. The stem12includes a bearing13formed on the interior surface of the tip end53. One end of an eccentric shaft14is inserted into the bearing13, and a weight15is coupled to the eccentric shaft14. The other end of the eccentric shaft14is linked to a rotary shaft of the motor M built in the gripping part11. The motor M, the eccentric shaft14, and the weight15form the drive assembly for generating oscillations. By rotating the rotary shaft of the motor M, the eccentric shaft14rotates. The weight15is fixed to the eccentric shaft14in the vicinity of the bearing13. Due to this weight15, the center of gravity of the eccentric shaft14is shifted from the center of rotation. Note that a minute clearance is provided between the eccentric shaft14and the bearing13.

Although the eccentric shaft14rotates along with the rotation of the rotary shaft of the motor M, since the center of gravity of the eccentric shaft14is shifted due rotation of the weight15, a motion of rotating about the center of rotation is achieved. Thus, the entire eccentric shaft14bends, and the stem12, along with the brush unit20coupled to the stem12, oscillates at a high speed. Thus, the stem12and the brush unit20form the oscillating assembly of the electric toothbrush10a. By oscillating the brush unit20using rotational movement of the eccentric shaft14in this manner, the brush unit20effectively oscillates in a direction parallel to the pressing direction of the brush22and perpendicular to the rotary shaft of the motor M.

In the exemplified embodiment, the entirety of the oscillating assembly (stem12and brush unit20) has a resonance point (resonance frequency), and can switch between a first operational mode in which the stem12and brush unit20oscillate in the pressing direction of the tooth cleaning elements22and a second operational mode in which the stem12and brush unit20oscillate in a plane perpendicular to the pressing direction of the tooth cleaning elements22. The electric toothbrush10amay switch between the first and second drive modes by controlling the rotary speed of the motor M.

The stem12also includes a light emitting element17and a light receiving element18fixed on a substrate16, and holes23aand24ain the cylindrical housing50. The hole23ais positioned on the stem12so that when the brush unit20is coupled to the stem12, the hole23ais positioned adjacent to the light transmitting part23. Similarly, the hole24ais positioned on the stem12so that when the brush unit20is coupled to the stem12, the hole24ais positioned adjacent to the light receiving part24.

The light emitting element17includes a light emitting diode (LED), a laser diode, and the like. The invention is not to be so limited, as other types of light generating devices may be used for the light emitting element17. The wavelength of light emitted from the light emitting element17may be appropriately selected according to the elements in the mouth (plaque, tartar, tooth decay, and the like) to be detected. The light emitting element17is positioned adjacent the hole23ain the interior of the stem12so that light emitted from the light emitting element17passes through the hole23a.

The light receiving element18includes a light sensing element, such as a photo diode or the like, that converts light into an electric signal. The invention is not to be so limited, as other types of light sensing elements may be used for the light receiving element18. The light receiving element18is positioned adjacent the hole24ain the interior of the stem12so that light passing through the hole24ais incident on the light receiving element18.

A substrate16includes wiring electrically connected to the light emitting element17and to the light receiving element18. In certain embodiments, a flexible substrate may be used as the substrate16. The substrate16extends to the interior of the gripping portion11, and the wiring formed on the substrate16is electrically connected to a controller, described below, which is positioned within the gripping portion11.

As illustrated inFIG.2, the cross-sectional shape of the first transmission member44, which forms part of the light transmitting part23, has a side wall running in a direction orthogonal to the pressing direction of the tooth cleaning elements22and extends in a slanted angle toward the light receiving part24. With this shape for the first transmission member44, light emitted from the light emitting element17passes through the hole23aof the stem12, and then through the first transmission member44, so that the light is directed toward the light receiving part24. The light transmitting part23therefore emits light in a direction that intersects the pressing direction of the tooth cleaning elements22, as opposed to emitting light parallel to the pressing direction, so that the emitted light is directed at least partially within a plane defined by the pressing direction and including both the light transmitting part23and the light receiving part24.

Similar to the first transmission member44, the cross-sectional shape of the second transmission member45, which forms part of the light receiving part24, has a side wall running in a direction orthogonal to the pressing direction of the tooth cleaning elements22and extends in a slanted angle toward the light transmitting part23. With this shape for the second transmission member45, light emitted by the light transmitting part23that is reflected by, for example, a tooth D, is received through the second transmission member45, as opposed to the second transmission member45receiving light from the pressing direction of the tooth cleaning elements22.

In certain embodiments, the side wall slant angle and distance from the tooth cleaning elements22of the first transmission member44may be determined so that light emitted from the light transmitting part23has no vignetting from the tooth cleaning elements22prior to being directed toward the light receiving part24. Similarly, in certain embodiments, the side wall slant angle and distance from the tooth cleaning elements22of the second transmission member46may be determined so that light emitted from the light transmitting part23has no vignetting from the tooth cleaning elements22after reflecting off a tooth D and prior to passing through the second transmission member45.

As shown inFIG.3, the gripping portion11includes a motor M, a controller90, and a notification unit91. The controller90controls the motor M to selectively drive the oscillating assembly, which is made up of the stem12and the brush unit20fixed thereon, in one of a first drive mode or a second drive mode. In the first drive mode, the oscillating assembly oscillates in a first direction that is parallel to the pressing direction of the tooth cleaning elements22, and in the second drive mode, the oscillating assembly oscillates in a second direction that is different from the pressing direction. The controller90switches between the first drive mode and the second drive mode by changing the rotary speed of the rotary shaft of the motor M.

In certain embodiments, the controller90may alternately switch between the first drive mode and the second drive mode. By automatically switching the oscillating direction of the brush unit20, a plaque removal effect can be achieved that excels when compared with brushing in only one direction. This improved plaque removal effect is due to, at least in part, the ends of the tooth cleaning elements22touching the teeth (and gums) from various angles while the electric toothbrush10ais in use, so that the switching of the oscillating direction changes the manner in which the ends of the tooth cleaning elements22touch the teeth (and gums). The driving method of the stem12by the controller90is not intended to limit the scope of the invention unless otherwise stated in the claims. For example, in certain embodiments, only the first drive mode may be performed, and in certain other embodiments, only the second drive mode may be performed. In certain other embodiments, the timing of switching between the first and second drive modes may be varied.

The controller90drives the light emitting element17, via electrical conductors included as part of the substrate16, and controls the manner in which light is emitted from the light emitting element17(e.g., always on, pulsed, pulse timing, and the like). The controller90also processes the output signal from the light receiving element18, with the signal output being received by the controller form electrical conductors included as part of the substrate16. The signal output from the light receiving element18is processed to determine a value of the output signal in order to determine one or more of the following: the amount of plaque adhering to a tooth, whether tartar is present on a tooth, whether tooth decay is present on a tooth, and the like. By way of example, the manner in which the controller90processes the output signal to calculate the amount of plaque present on a tooth is described in greater detail.

The notification part91notifies the user of the electric toothbrush10ausing a notification device such as a speaker or a light emitting diode (LED). Other types of notification devices may be used, as the invention is not to be so limited. Thus, in certain embodiments, the notification unit91follows commands from the controller90, and notifies the user by making a sound or lighting an LED. The content of the notification may include the amount of plaque identified by the controller90. For example, the notification unit91may inform the user as to the amount of plaque identified by lighting an LED in a green color if the amount of plaque is extremely low, or by lighting an LED in a red color if there is a significant amount of plaque present. By providing different notifications identifying the amount of plaque present, the electric toothbrush10ahelps to support effective teeth brushing.

The operation of the electric toothbrush10aconfigured as described above will now be described. When the power of the electric toothbrush10ais set to on and a brushing start operation is performed, the controller90alternately performs the first drive mode and the second drive mode. By this, the brush unit20pressed against one or more teeth alternately repeats an oscillation in the first direction followed by an oscillation in the second direction, so that plaque adhering to the tooth may be removed by the tooth cleaning elements22. Also following the brushing start operation, the controller90controls the light emitting element17so that light is emitted while the first drive mode and second drive mode are alternately being performed. After light emitted from the light emitting element17passes through the hole23a, it is emitted in a diagonal direction from the light transmitting part23. Light emitted from the light transmitting part23is incident on the tooth D (or more than one tooth) where the plurality of tooth cleaning elements22are pressed, and may be reflected off the surface of the tooth D. In certain embodiments, light incident on the surface of the tooth D may induce (through stimulated emission or fluorescence) another wavelength of light to be emitted from a substance, such as plaque, present on the surface of the tooth D. Such an induced emission may occur when, for example, the light transmitting part23emits a blue light and plaque is present on the tooth D, so that the light emitted by the plaque is a red light. In the remainder of the discussion below, it is to be understood that where light reflecting off a tooth D is discussed, that such induced emissions may also be present and detected separately or simultaneously. Light, whether reflected or from induced emission, from the tooth D enters the light receiving part24, passes through the hole24a, and is received in the light receiving element18. The light receiving element18converts the received light into an electric signal, which forms the output signal received by the controller90. The controller90determines an amount of plaque on the brushed portion of the tooth D by processing the output signal from the light receiving element18. Then, the controller90notifies the user through the notification part91to inform the user about the determined amount of plaque.

In the exemplified embodiment shown inFIGS.1-3, a large portion of light from the light emitting element17is emitted from the light transmitting part23in a direction that intersects the pressing direction in which the tooth cleaning elements22extend. This direction heads from the light transmitting part23toward the light receiving part24in the planar view ofFIG.1. Therefore, plaque on a surface opposing the front surface41where the tooth cleaning elements22are formed (e.g., tooth D where the plurality of tooth cleaning elements22contact while brushing teeth) can be accurately detected.

Furthermore, in the exemplified embodiment shown inFIGS.1-3, it is possible for the light receiving part24to receive light coming from a direction that intersects the pressing direction in which the tooth cleaning elements22extend. This direction heads from the light transmitting part23toward the light receiving part24in the planar view ofFIG.1. Because of this, a large portion of light emitted from the light emitting element17which is reflected by the tooth D may be received by the light receiving element18. Consequently, the amount of signal output from the light receiving element18may be increased, and detection sensitivity of plaque can be raised.

In this manner, the user of the electric toothbrush10ais accurately informed in real time by the notification unit91about the amount of plaque on a tooth being brushed by the tooth cleaning elements22. Because of this, it becomes possible to perform more effective tooth brushing. Furthermore, detection accuracy of plaque at a site being brushed is improved by light being emitted diagonally from the light transmitting part23, even when the distance between the light transmitting part23and the light receiving part24is large. When the distance between the light transmitting part23and the light receiving part24is close, a region where the density of the tooth cleaning elements22becomes coarse becomes larger. However, according to the exemplified embodiment inFIG.1, because the light transmitting part23and the light receiving part24are separately, the region where the density of the tooth cleaning elements22becomes coarse is dispersed. As a result, the plaque detection capabilities of the electric toothbrush10aare not significantly reduced, if at all, by the tooth cleaning elements22.

In embodiments in which the distance between the light transmitting part23and the light receiving part24in the brush unit20is large, the light transmitting part23and the light receiving part24can be arranged as much on an edge of the front surface41of the brush unit20, where the tooth cleaning elements22are formed. In such embodiments, the number of tooth cleaning elements22can be increased, and plaque removing abilities can be improved.

In the exemplified embodiment shown inFIG.1, each of the light transmitting part23and the light receiving part24are arranged in a location on the front surface41of the brush unit20so that each is surrounded on three sides by the tooth cleaning elements22. With such an arrangement, the brush unit20can be made smaller when compared with each of the light transmitting part23and the light receiving part24being arranged outside of the respective recesses formed by the arrangement of the tooth cleaning elements22. Moreover, by the arrangement shown inFIG.1, the distance between the light transmitting part24and the light receiving part24may be made smaller, and the detection accuracy of plaque and the like can be improved.

Furthermore, the brush unit20in the exemplified embodiment has a limited number of parts coupled to the housing, including the tooth cleaning elements22, the first transmission member44, and the second transmission member45. Because of this, manufacturing costs can be reduced. Moreover, because the brush unit20may be disposable, the benefits of reducing manufacturing costs are very large.

Although the exemplified embodiment is shown with the eccentric shaft14and the weight15to generate the oscillations in either of the first direction or the second direction, the invention is not to be so limited. For example, in certain embodiments, the oscillations may be generated by a configuration that can integrally oscillate the stem12and the brush unit20in the first direction and the second direction. For example, it may be a configuration that oscillates the oscillating assembly in the first direction and the second direction by sonic wave oscillation.

FIG.4shows a cross section of another exemplified embodiment of an electric toothbrush10b. InFIG.4, the same numerals are given to similar components as those shown and described in conjunction withFIGS.1-3, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10b, the shape of the bristle field formed by the tooth cleaning elements22is different, as is the positions of the light transmitting part23and the light receiving part24with respect to the tooth cleaning elements22. Within the bristle field, the tooth cleaning elements22nearest the light transmitting part23and those nearest the light receiving part24are shorter than those tooth cleaning elements closer to the middle portion of the bristle field. By way of specific example, eight teeth cleaning elements22are illustrated inFIG.4, and the shape that connects each top face, each bottom face, the right side face of the rightmost brush22, and the left side face of the leftmost brush22is a shape with two corners of the rectangle cut. In other words, the free ends of the tooth cleaning elements22nearest both the light transmitting part23and the light receiving part24are truncated at an angle.

FIG.5shows a cross section of another exemplified embodiment of an electric toothbrush10c. InFIG.5, the same numerals are given to similar components as those shown and described in conjunction withFIGS.1-3, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10c, the shape of the bristle field formed by the tooth cleaning elements22is different, as is the positions of the light transmitting part23and the light receiving part24with respect to the tooth cleaning elements22. Within the bristle field, the tooth cleaning elements22nearest the light transmitting part23and those nearest the light receiving part24are shorter than those tooth cleaning elements closer to the middle portion of the bristle field. By way of specific example, eight teeth cleaning elements22are illustrated inFIG.5, the height of the four teeth cleaning elements22in the center are the highest, and the teeth cleaning elements22become shorter heading toward the light transmitting part23from these four teeth cleaning elements22in the center. Similarly, the height of the teeth cleaning elements22becomes shorter heading toward the light receiving part24from these four teeth cleaning elements22in the center.

The configuration of the teeth cleaning elements22illustrated inFIG.4can be one in which, as compared to the eight teeth cleaning elements22illustrated inFIG.5, the free ends of the two teeth cleaning elements22closest to the light transmitting part23are slanted along the emitting direction of light emitted from the light transmitting part23, and the free ends of the two teeth cleaning elements22closest to the light receiving part24are slanted along the progressing direction of light emitted from the light transmitting part23and reflected toward the light receiving part24.

By forming the teeth cleaning elements between the light transmitting part23and the light receiving part24in the configurations shown in the embodiments ofFIGS.4and5, vignetting by the teeth cleaning elements22is significantly reduced, if not eliminated, for light emitted from the light transmitting part23toward the tooth. Similarly, vignetting by the teeth cleaning elements22is significantly reduced, if not eliminated, for light reflecting off the tooth and heading toward the light receiving part24. Therefore, by these configurations, plaque detection accuracy may be improved.

Configurations of an electric toothbrush have so far been described in which the light emitting element17and the light receiving element18are included on the stem12. However, in certain embodiments, the light emitting element17and the light receiving element18may be included on the front surface41where the teeth cleaning elements22of the brush unit20are formed.FIG.6shows a cross section of another exemplified embodiment of an electric toothbrush10d. InFIG.6, the same numerals are given to similar components as those shown and described in conjunction withFIGS.1-3, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10d, the positions and arrangements of the light emitting element17and the light receiving element18are different. Specifically, in this embodiment, the light emitting element17and the light receiving element18are positioned on the front surface41of the brush unit20, so that both the light emitting element17and the light receiving element18are external to the housing of the brush unit20. The positional arrangement of the light emitting element17on the front surface41, with respect to the bristle field of the teeth cleaning elements22, is the same as the positional arrangement of the light transmitting part23inFIG.1. Similarly, the positional arrangement of the light receiving element18on the front surface41, with respect to the bristle field of the teeth cleaning elements22, is the same as the positional arrangement of the light receiving part24inFIG.1.

As illustrated inFIG.6, the light emitting element17is arranged at an angle so that the light emitting face is directed partially in the direction of the light receiving element18, on the opposite side of the bristle field of the teeth cleaning elements22, and partially in the direction of the pressing direction of the teeth cleaning elements22. Similarly, the light receiving element18is arranged at an angle so that the light receiving face is directed partially in the direction of the light emitting element17, on the opposite side of the bristle field of the teeth cleaning elements22, and partially in the direction of the pressing direction of the teeth cleaning elements22. The angles at which the light emitting element17and the light receiving element18may vary, and are not intended to limit the invention unless so stated in the claims.

With the configuration of this exemplified embodiment, the light emitting element17emits light in a direction that intersects the pressing direction of the teeth cleaning elements22, rather than in a direction that is parallel to the pressing direction of the teeth cleaning elements22, so that the emitted light is directed toward the light receiving element18. In addition, the by arranging the light receiving element18at an angle, more light that is emitted by the light emitting element17and reflected off a tooth is received by the light receiving element18.

In the exemplified embodiment ofFIG.6, the light emitting element17fulfills the same function as the light transmitting part23ofFIG.1, and the light receiving element18fulfills the same function as the light receiving part24ofFIG.1. Therefore, in this exemplified embodiment, plaque and the like on a tooth can be accurately detected during brushing.

FIG.7shows a top planar of another exemplified embodiment of an electric toothbrush10e. InFIG.7, the same numerals are given to similar components as those shown and described in conjunction withFIG.1, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10e, the positions of the light transmitting part23and the light receiving part24are different with respect to the bristle field formed by the teeth cleaning elements22. Specifically, the recesses are included on each of two long sides of the outer edge21of the bristle field, and the light transmitting part23and the light receiving part24are each positioned within one of the recesses, respectively. The same improvements as the electric toothbrush10ainFIG.1can be obtained with this alternative configuration.

It has been noted that when teeth are being brushed pressing the teeth cleaning elements22to a tooth, the teeth cleaning elements22may collapse toward the short direction of the brush unit20. However, during use of the electric toothbrush10e, the teeth cleaning elements22only collapse from one direction on each of the light transmitting part23and the light receiving part24. Because of this, the plaque detection capabilities of the electric toothbrush10eare not significantly reduced, if at all, due to collapsing of the tooth cleaning elements22.

FIG.8shows a cross section of another exemplified embodiment of an electric toothbrush10f. InFIG.8, the same numerals are given to similar components as those shown and described in conjunction withFIGS.1-3, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10f, the light emitting element17and the light receiving element18are fixed on an isolating member25, and the isolating member25is fixed to the substrate16.

The isolating member25may be formed from a material having a resonant frequency different from one or both of the oscillation frequencies of the first drive mode and the second drive mode for driving the oscillating assembly (stem12and brush unit20) by rotation of the motor M. In certain embodiments, the isolating member25may be, for example, urethane. As such, it is understood that the isolating member25does not wholly isolate the light emitting element17and the light receiving element18from all vibrations; rather, the isolating member25dampens vibrations present in the oscillating part so that those vibrations have a reduced impact on the light emitting element17and the light receiving element18.

With the electric toothbrush inFIG.2, the control unit50driving the motor M, and thus also the eccentric shaft14and weight15, the light emitting element17and the light receiving element18are also subject to high speed oscillations. Because of this, there is a possibility that these oscillations will reduce the detection accuracy of plaque. Furthermore, the brush unit20is configured so that the distance of the light transmitting part23and the light receiving part24can be made larger, with the light transmitting part23and the light receiving part24arranged on opposite sides of the bristle field formed by the teeth cleaning elements22. The increased distance may result in a time lag occurring between the time light is emitted from the light emitting element17and the time the reflected light is received by the light receiving element18, and this time lag may further contribute to a reduction in detection accuracy of plaque in combination the oscillations.

With the exemplified embodiment shown inFIG.8, because the light emitting element17and the light receiving element18are fixed on the isolating member25, the vibratory motion of the light emitting element17and the light receiving element18can be reduced even when the oscillating assembly is oscillating. Because of this, improved endurance of the electric toothbrush and improved detection accuracy of plaque can be expected.

Note that inFIG.8, the light emitting element17and the light receiving element18are fixed on the isolating member25, however in certain embodiments, only the light receiving element18may be fixed on isolating member25, and with the light emitting element17fixed as described above inFIG.2. Because the effects of oscillation are higher for the light receiving element18, it may be so that at least the light receiving element18is fixed on the isolating member25.

FIG.9shows a cross section of another exemplified embodiment of an electric toothbrush10g. InFIG.9, the same numerals are given to similar components as those shown and described in conjunction withFIG.4, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10g, the light transmitting part23and the light receiving part24are fixed on the isolating member25, and the isolating member25is fixed to the substrate16in a similar manner as described above for the embodiment shown inFIG.8. In this embodiment of the electric toothbrush10g, the shape of the bristle field formed by the tooth cleaning elements22is formed so that the tooth cleaning elements22nearest the light transmitting part23and those nearest the light receiving part24are shorter than those tooth cleaning elements closer to the middle portion of the bristle field, in a manner such as is described in detail above with respect toFIG.4.

FIG.10shows a cross section of another exemplified embodiment of an electric toothbrush10h. InFIG.10, the same numerals are given to similar components as those shown and described in conjunction withFIG.5, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10h, the light transmitting part23and the light receiving part24are fixed on the isolating member25, and the isolating member25is fixed to the substrate16in a similar manner as described above for the embodiment shown inFIG.8. In this embodiment of the electric toothbrush10h, the shape of the bristle field formed by the tooth cleaning elements22is formed so that the tooth cleaning elements22nearest the light transmitting part23and those nearest the light receiving part24are shorter than those tooth cleaning elements closer to the middle portion of the bristle field, in a manner such as is described in detail above with respect toFIG.5.

FIG.11shows a cross section of another exemplified embodiment of an electric toothbrush10i. InFIG.11, the same numerals are given to similar components as those shown and described in conjunction withFIG.6, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush10i, the light emitting element17and the light receiving element18are fixed on respective isolating members25a,25b, and the isolating members25a,25bare fixed to the front surface41of the brush unit20. The function of the isolating members25a,25bare the same as the isolating member25described above with respect toFIG.8.

As discussed above, in certain embodiments, the controller90may alternate between the first drive mode and the second drive mode. In certain of these embodiments, the controller may also drive the light emitting element17so that the light emitting element17emits light only during the first drive mode. When the first drive mode is active, the path of light emitted from the light transmitting part23and received by the light receiving part24is always a constant straight line in the planar view ofFIG.1, and that path does not substantially move in the plane formed of the tooth cleaning elements122. This is because, as described above, during the first drive mode, the oscillations of the oscillating assembly (the stem12and the brush unit20) are parallel to the pressing direction of the tooth cleaning elements122. On the other hand, when the second drive mode is active, the path is not a constant straight line in the planar view ofFIG.1. This is because, as described above, during the second drive mode, the oscillations of the oscillating assembly are in a second direction that is different from the pressing direction, such that at least part of the oscillations during the second drive mode is not parallel to the pressing direction. Thus, during the second drive mode, there is the possibility of decreasing the detection accuracy of plaque. Therefore, by operating the light transmitting part23and the light receiving part24only when the first drive mode is active, plaque and the like on the teeth D may be more accurately detected.

In certain embodiments, the controller90may control the light emitting element17to emit light during both the first drive mode and during the second drive mode. In such embodiments, the controller90may process the output signal from the light receiving element18to detect plaque and the like only when the first drive mode is active. In this manner, plaque may still be more accurately detected.

In addition, as described above, when the second drive mode is active, there is a possibility that a portion of the tooth cleaning elements122will overlap the light transmitting part23and the light receiving part24in a planar view. Therefore, it may be particularly effective for the controller90to perform the plaque detection process only when the first drive mode is active.

In certain embodiments, the second drive mode may create oscillations in one of a plurality of different directions, with each oscillation direction being different from, and intersecting, the pressing direction. In such embodiments, the controller90may select any one of the oscillation directions for the second drive mode when alternating between the first drive mode and the second drive mode.

As discussed above, in embodiments which employ the isolating member25, the isolating member may be formed from a material having a resonant frequency different from one or both of the oscillation frequencies of the first drive mode and the second drive mode for driving the oscillating assembly.

Alternative embodiments of an electric toothbrush for improving the detection of plaque and the like on teeth are illustrated inFIGS.12-17. Unless expressly or impliedly contraindicated, the considerations and alternatives discussed above for other embodiments may apply equally to the embodiments ofFIGS.12-17. Referring toFIGS.12and13concurrently, an electric toothbrush100ais shown in accordance with an embodiment of the present invention.FIG.12is a planar view illustrating a schematic configuration of the electric toothbrush100aviewed from the brush pressing direction, andFIG.13is a cross-sectional view taken along line A-A ofFIG.12.

The electric toothbrush100aincludes a gripping part110that includes a battery and an electric control system therein, as well as a main body having a stem111fixed to the gripping part110, and a brush unit120that can be detached from the stem111. The stem111extends from the gripping part110and forms the portion of the electric toothbrush100ato which the interior hollow part120aof the brush unit120may be coupled. The brush unit120may be repetitively coupled to and detached from the stem111as necessary or desired. The brush unit120and the stem111may also include corresponding structures that facilitate locking the brush unit120to the stem111. Thus, the gripping part110and the stem111may be reused with different brush units120having different structural arrangements to achieve different purposes. Furthermore, the brush unit120may be replaced when the tooth cleaning elements thereon are worn or splayed over time.

The brush unit120includes a front surface141and an opposite rear surface142. Furthermore, the brush unit120includes a plurality of tooth cleaning elements122extending from the front surface141. One of the tooth cleaning elements122a(the one with an oblique profile) also functions as a detecting part for detecting plaque, tartar, tooth decay, and the like. The plurality of tooth cleaning elements122are depicted in various aligned columns and rows, although the invention is not to be so limited. The number, pattern, configuration, and structure of the tooth cleaning elements122is not to be limited in all embodiments. In certain embodiments, the tooth cleaning elements122are formed by a plurality of bristles that are bundled together into tufts that are then coupled to a head of the brush unit120.

From among the tooth cleaning elements122extending from the outer peripheral face of the brush unit120, one end of each tooth cleaning elements122, not including the tooth cleaning elements122A, is inserted into a concave receptacle formed on the front surface141of the brush unit120. The fixed ends of the tooth cleaning elements122may be adhered and fixed with the concave receptacles of the brush unit120by an adhesive. Of course, the invention is not to be so limited, as the tooth cleaning elements122may be coupled to the head using staple technology, anchor-free tufting technologies, in-mold tufting technologies, or any other technology now known or later discovered. The tooth cleaning elements122may include bristles alone, bristles in combination with lamella formed of an elastomeric material, only bristles formed of an elastomeric material, or the like. The invention is not to be particularly limited by the specific details of the bristles unless specifically claimed as such. As discussed above, in certain embodiments the brush unit120may be detachable from the stem111and replaceable as needed when the tooth cleaning elements122thereon become frayed from use.

The fixed end of the tooth cleaning element122A extending from the front surface141of the brush unit120is inserted into a hole145included in the front surface141of the brush unit20. The fixed end of the tooth cleaning element122A is adhered within this hole by an adhesive. In this manner, the fixed end of the tooth cleaning element122A is exposed on the interior of the hollow part120aof the brush unit120, whereas the fixed ends of the other tooth cleaning elements122, other than the tooth cleaning element122A, are not exposed on the interior of the hollow part120aof the brush unit120. There is a possibility of water infiltrating in the hollow part120abetween the brush portion122A and the hole provided on the housing of the brush unit120. Because of this, it is preferable to use an adhesive that also serves to provide waterproofing as the adhesive that adheres this hole145and the brush portion22A.

As is shown inFIG.13, the brush unit120includes a cylindrical housing150with the tip end151being closed to form a hollow part120a. The stem111includes a tube shaped housing152with the tip end153closed. By fitting the stem111into the hollow part120a, the main body unit and the brush unit120may be coupled together. The stem111includes a bearing112formed on the interior surface of the tip end153. One end of an eccentric shaft113is inserted into the bearing112, and a weight114is coupled to the eccentric shaft113. The other end of the eccentric shaft113is linked to a rotary shaft of the motor M built in the gripping part110. By rotating the rotary shaft of the motor M, the eccentric shaft113rotates. The weight114is fixed to the eccentric shaft113in the vicinity of the bearing112. Due to this weight114, the center of gravity of the eccentric shaft113is shifted from the center of rotation. The motor M may be controlled by a controller, such as in any manner discussed above, to oscillate the stem111and the brush unit120. The oscillations may also be generated by other means.

The stem111also includes a light emitting element116, a light receiving element117, a band pass filter118, and a light guide119. The light emitting element116, the light receiving element117, and the band pass filter118are fixed to the light guide119. The light emitting element116includes a light emitting diode (LED), a laser diode, or the like. The invention is not to be so limited, as other types of light generating devices may be used for the light emitting element116. The wavelength of light emitted from the light emitting element116may be appropriately selected according to the elements in the mouth (plaque, tartar, tooth decay, and the like) to be detected. For example, when detecting plaque, a light emitting element116is used that emits blue light. The light emitting element116is connected to a controller, such as is described above with reference toFIGS.1and2, built in the gripping part110by a lead wire. The light receiving element117includes a light sensing element, such as a photo diode or the like, that converts light into an electric signal. The invention is not to be so limited, as other types of light sensing elements may be used for the light receiving element117. The light receiving element117is connected with the controller built in the gripping part10by a lead wire or the like.

The band pass filter118is included to spectrally limit the wavelength of light received by the light receiving element117. For example, when the electric toothbrush has a function of detecting plaque, the band pass filter118may include a filter characteristic where blue light emitted from the light emitting element116is blocked, and red light generated by the plaque, in response to the incident blue light, is allowed to pass.

The light guide119has an end portion fitted to the hole115of the stem111so that the end portion of the light guide119is positioned opposite the end of the tooth cleaning element122athat is exposed within the hollow part120A of the brush unit120. The light guide119guides light emitted from the light emitting element116to the tooth cleaning element122A, and it guides light received from the tooth cleaning element122A to the light receiving element117via the band pass filter118. The light guide119passes light emitted from the light emitting element116, and it is therefore formed of a material that passes light that is to be sensed by the light receiving element117. Examples of material that may be used for the light guide119include, for example, acryl, polycarbonate, of the like. The light guide119may also include a metal film deposited on its surfaces, excluding the surface opposing the tooth cleaning element122A and the surface passing light to the light emitting element16and the band pass filter18. The inclusion of the metal film helps to prevent light entering the light guide119from leaking to the exterior of the light guide119, except for in the two aforementioned locations.

During operation, the controller controls the operation of light emitted from the light emitting element116. For example, as discussed above, the controller, may control the light emitting diode116to alternate between a first drive mode and a second drive mode. The controller in this embodiment may control the light emitting element116and the light receiving element117in any of the manners previously discussed. When light is emitted from the light emitting element116, the light guide119guides the light into the end of the tooth cleaning element122A exposed within the hollow part120aof the brush unit120. Light that has entered the tooth cleaning element122A proceeds to the free tip end of the tooth cleaning element122A. In embodiments in which the tooth cleaning element122A is formed of a plurality of fibers, light entering the tooth cleaning element122A proceeds to the free tip end of each of the fibers of the tooth cleaning element122A. At the free tip end of the tooth cleaning element122A, the light is emitted to the exterior of the tooth cleaning element122A. The light emitted from the tooth cleaning element122A is incident on the surface of a tooth D on the site where the plurality of tooth cleaning elements122are pressed.

During uses when blue light is emitted from the light emitting element116, when the blue light is incident on the surface of a tooth D where there is plaque, the plaque will generate a red light in response to the incident blue light. Red light emitted from the plaque enters the tooth cleaning element122A and is received by the light guide119, which guides the received light to the band pass filter18. Because red light can pass through the band pass filter18, the red light is received by the light receiving element117. The light receiving element117converts the received red light into an electric output signal, which is communicated to the controller. The controller determines the amount of plaque on the tooth D by analyzing the output signal from the light receiving element117. The controller may then notify the user, using the notification part discussed above, concerning the amount of plaque detected on the tooth D. By this process, it is possible to sense plaque adhering to the site on the tooth D against which the tooth cleaning element122A is pressed, so that the user may be notified in real-time about the amount of plaque detected on the tooth D.

An advantage of the electric toothbrush100aofFIGS.12-13is that the brush portion122A is employed both for sensing plaque and for brushing the teeth to remove plaque. Because of this, it is possible to sense plaque adhered to a tooth being brushed without reducing the number of tooth brushing elements on the front surface141of the brush unit120, thereby eliminating the need to make the brush unit120larger to accommodate the light emitting and light sensing functionality.

As another advantage of the electric toothbrush100aofFIGS.12-13is that the brush unit120is a simple configuration in which tooth cleaning elements122include only one portion that is configured as the tooth cleaning element122A. Moreover, in certain embodiments, the tooth cleaning element122A may be formed of the same material the rest of the tooth cleaning elements122. Thus, the differences between the brush unit120and a conventional brush unit is minimized. Because of this, manufacturing costs of the brush unit120can be reduced. Also, because the brush unit20is expendable, the benefits of reducing manufacturing costs are very large.

It is to be noted that in the exemplified embodiment ofFIGS.12-13, the fixed end of the tooth cleaning element122A is physically exposed within the hollow part120aof the brush unit120. However, the fixed end of the tooth cleaning element122A may be optically exposed within the hollow part20aof the brush unit120. The fixed end being optically exposed refers to a state where the fixed end can be seen from the hollow part20aby light at the wavelength emitted from the light emitting element116and by light at the wavelength to be received by the light receiving element117.

FIG.14shows a cross section of another exemplified embodiment of an electric toothbrush100b. InFIG.14, the same numerals are given to similar components as those shown and described in conjunction withFIGS.12-13, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush100b, one portion of the hole145, on the side of the hollow part120aof the brush unit120, included in the front surface141of the brush unit120is filled by a material146that is transparent to light in the operational wavelength of the electric toothbrush100b. The fixed end of the tooth cleaning element122A is adhered and fixed within the hole145by an adhesive transparent to light in the operational wavelength. With this configuration, the fixed end of the tooth cleaning element122A is optically exposed within the hollow part120a.

An advantage of the electric toothbrush100bofFIG.14is that manufacturing costs can be reduced because the tooth cleaning elements122included as part of the brush unit120can all have the same dimensions. Furthermore, as compared to the electric toothbrush100ashown inFIG.13, the waterproofing of the electric toothbrush100bis improved because the presence of the material146in the hole145prevents water from infiltrating into the hollow part120aof the brush unit120.

Above, an exemplified embodiment is described in which only one of the tooth cleaning elements122, namely tooth cleaning element122A, included on the brush unit120serves to transmit and receive light to detect plaque and the like on teeth. The invention is not so limited, as a plurality of the tooth cleaning elements122may serve to transmit and receive light for detection of plaque and the like.

FIG.15shows a cross section of another exemplified embodiment of an electric toothbrush100c. InFIG.15, the same numerals are given to similar components as those shown and described in conjunction withFIGS.12-13, and the descriptions of such similar components are omitted. In this embodiment of the electric toothbrush100c, all of the tooth cleaning elements122A transmit and receive light for detecting plaque and the like on a tooth. In this embodiment, a light guide119A is positioned in the interior of the stem111within a hole115A formed in the stem111. The light guide119A guides light emitted from the fixed end of each tooth cleaning element122A to the light receiving element117via the band pass filter118. The light guide119A also guides light emitted from the light emitting element116to the fixed ends of each tooth cleaning element122A. In this manner, plaque detection accuracy can be raised because all of the tooth cleaning elements122A transmit and receive the light used for detecting plaque and the like.

In certain embodiments which include multiple tooth cleaning elements122A for transmitting and receiving light, each tooth cleaning element122A may be associated with a separate light guide119, light emitting element116, light receiving element117, and band pass filter118, such that the stem111includes multiple ones of each of the light guide119, the light emitting element116, the light receiving element117, the and band pass filter118. In such embodiments, even if one of the plurality of tooth cleaning elements122A breaks, plaque sensing can still continue. Additionally, by sensing the amount of plaque using several independent sub-systems, the accuracy of detecting plaque can be improved.

FIGS.16-17show another exemplified embodiment of an electric toothbrush100d. A top planar view is shown inFIG.16, and the same numerals are given to similar components as those shown and described in conjunction withFIG.12, with the descriptions of such similar components being omitted. In this embodiment of the electric toothbrush100d, the surface area of the tooth cleaning element122A included as part of the brush unit120is larger than the surface area of the tooth cleaning elements122. As shown inFIG.17, the width of the tooth cleaning element122A is larger, and the width of the light guide119is larger, as compared to the embodiment of the electric toothbrush100ashown inFIG.13.

With the tooth cleaning element122A having a larger surface area, the amount of light emitted toward a tooth can be increased and the amount of light received from the tooth (by reflection or induced emission) can be increased. Because of this, plaque detection accuracy can be improved.

In the exemplified embodiment ofFIGS.16-17, although there is only one tooth cleaning element122A shown, it is to be understood that certain embodiments may include multiple tooth cleaning elements122A.

In the embodiments described above, each have the light guide119, the light emitting element116, the light receiving element117, and the band pass filter118positioned within the interior of the stem111. In certain embodiments, these components may be positioned on the outer peripheral face of the stem111. The invention is not to be limited by the positioning of these components unless expressly stated in the claims. However, embodiments in which these components are on the interior of the stem111are preferred because doing so enables the stem111to be made smaller.

Similarly, in the embodiments described above, each have the light emitting element116, the light receiving element117, and the band pass filter118positioned within the interior of the stem111. In certain embodiments, these components may be positioned in the gripping part110. In such embodiments, an optical fiber is included extending from the interior of the stem111to the gripping part110. By way of example, a first optical fiber may be included which has one end receiving light from the light emitting element116and the other end transmitting light to the light guide119, and a second optical fiber may be included which has one end receiving light from the light guide119and the other end transmitting light to the light receiving element117. The band pass filter118may be located between the second optical fiber and the light guide119or between the second optical fiber and the light receiving element117. In such embodiments, the light guide119and the two optical fibers function as the light guide. With such a configuration, an improvement of plaque detection accuracy can be expected because the light receiving element117would be less affected by the oscillation of the stem111. Alternatively, a single optical fiber could be used instead of the two optical fibers.

For the embodiments shown and described in connection withFIGS.12-17, in which the light emitting element116and the light receiving element117are included as part of the stem111, the loss of light within the mouth can be minimized, thereby increasing the amount of light which is received by the light receiving element17. Because of this, an improvement in plaque detection accuracy can be expected.

Also, in the embodiments shown and described in connection withFIGS.12-17, the tooth cleaning element122A, or alternatively each fiber forming part of the tooth cleaning element122A, needs to be formed of an optical transmission material which is at least transparent to light emitted from the light emitting element116and light to be received by the light receiving element117. In certain embodiments, these properties may be met by selecting from among materials that are currently used generally for toothbrushes. In this manner, manufacturing costs may be reduced.

In certain embodiments the exposed longitudinal surfaces of the tooth cleaning element122A, excluding the tip end, or alternatively each fiber forming part of the tooth cleaning element122A, may be coated to prevent light from escaping to the exterior through parts of the tooth cleaning element122A other than the tip end. For example, a coating of polyetrafluoroethylene (PTFE) or the like may be applied on the peripheral face of the tooth cleaning element122A. With this configuration, plaque sensing accuracy can be improved.

In certain embodiments, the electric toothbrush may be of the type that removes plaque by rotating a platform to which the tooth cleaning elements are coupled. In such embodiments, the tooth cleaning element122A may be positioned at the center of rotation of the platform. Plaque can therefore also be accurately detected in such embodiments.

While the invention has been described with respect to specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.