# Patent

## Title
Method and device for cleaning teeth

## Abstract

The invention is directed to a method and a device for cleaning teeth wherein a variety of cleaning tools are coupled to a common handle section for the individual cleaning of teeth. It relates in particular to a handle section of an electric dental cleaning device, with a coupling section for coupling various cleaning tools thereto, as well as said cleaning tools. According to the invention the handle section detects a coding provided on the respective cleaning tool attached. In dependence upon the respective coding detected, various functions of the dental cleaning device are controlled.

## Background
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 10/872,016, filed Jun. 18, 2004, now U.S. Pat. No. 7,770,251 which is a continuation of Ser. No. 10/662,237, filed Sep. 15, 2003, now U.S. Pat. No. 7,024,717, which is a continuation under 35 U.S.C. §120 of PCT International Application No. PCT/EP01/02844, filed Mar. 14, 2001, the contents of which are incorporated by reference in their entirety.


This invention relates to a method for cleaning teeth by means of an electric dental cleaning device having coupled to its handle section various cleaning tools for the individual tooth cleaning of the users of the dental cleaning device. The present invention further relates to the handle section of an electric dental cleaning device, in particular toothbrush, which possesses a coupling section for the coupling of a variety of cleaning tools, a drive mechanism for driving the respective coupled cleaning tool, and a control device. The present invention finally relates to the cleaning tools, particularly brush attachments, for such a handle section.
Dental cleaning devices such as electric toothbrushes or electric oral irrigators customarily have a grip or a handle section to which a variety of cleaning tools such as brush attachments are attachable, thus enabling several users to use the dental cleaning device with their own, user-related cleaning tools. Such electric toothbrushes are known, for example, from DE 19627752 A1 or EP 0624079 B1. To meet the users' wishes and requirements with regard to the cleaning of their teeth, the respective user has the possibility of individually adjusting dental cleaning parameters as, for example, the strength of the water jet of oral irrigators or the speed of the brush attachments of electric toothbrushes.
From DE 299 15 858 U1 a dental cleaning device is known in which each of the different toothbrushes can be inserted only into its assigned receptacle in a console. This then starts the program provided for this particular toothbrush. Particularly children find it however difficult to locate the individual opening for insertion of their personal toothbrush and for mating engagement of the plug. Furthermore, this console involves high complexity of manufacture, considering that it requires the provision of a plurality of different receptacles and each of the toothbrushes has a different plug assigned to its own receptacle.
In a further device disclosed in U.S. Pat. No. 5,184,959, each hand toothbrush is assigned its own accommodating slot in a housing, so that each toothbrush can be assigned an individual brushing time signal via the housing. This arrangement is very elaborate from the manufacturing point of view without providing for the detection and storage of user-specific data of the tooth cleaning operation.
Such dental cleaning devices are capable of improvement on many counts. In particular it is desirable to further improve the possible adaptation to the users as well as the user friendliness.
It is therefore an object of the present invention to provide an improved method for cleaning teeth, an improved handle section of an electric dental cleaning device and/or improved cleaning tools therefor, which further develop the cleaning of teeth relative to the prior art and afford further advantages. In particular, the invention aims to further improve the adaptation to the individual users as well as the user friendliness.
With regard to the method aspects, according to the invention this object is substantially accomplished in a tooth cleaning method of the type initially referred to in that a coding provided on the respective cleaning tool used is detected by the handle section preferably automatically and that, in dependence upon the detected coding, the handle section controls dental cleaning parameters preferably automatically and/or detects user-specific dental cleaning data preferably automatically. Preferred embodiments of the invention are the subject-matter of the subclaims.
With regard to the device aspects, according to the invention the object referred to is substantially accomplished in a handle section of an electric dental cleaning device of the type initially referred to in that the handle section possesses a coding detection device to detect an individual coding of the particular cleaning tool attached to the handle section, as well as a control device for the control of at least one function of the dental cleaning device in response to the detected coding. With regard to the cleaning tool of the type initially referred to, the object is substantially accomplished in that it possesses a magnetic, electrical, capacitive, electromagnetic and/or mechanical coding device or a combination of such coding devices. Preferred embodiments of the invention regarding the device are likewise the subject-matter of dependent claims.
Accordingly, the handle section detects the cleaning tool just attached and controls, in dependence upon the detected cleaning tool, one or preferably more functions of the dental cleaning device. Assuming, of course, that each handle section user uses his or her own, user-related cleaning tool, the control device of the handle section in particular is capable of establishing automatically, by referring to the coding detected on the cleaning tool, the identity of the user currently using the dental cleaning device. There is no need for any user input as, for example, a fingertip pressure and the like to inform the dental cleaning device of its current user. Hence an automatic adaptation to the respective user can also be made. This results in a maximum of user friendliness.
In particular in a further feature of the invention the control device is capable of adapting operating parameters such as cleaning frequency, cleaning speed and cleaning time or threshold value or desired range of application pressure automatically to the individual user identified. A variety of user profiles can be set and stored, one of which is put to use by the control device after the coding of the cleaning tool being used has been detected at the beginning of the cleaning operation and, hence, the respective user has been established. To this effect the coding detection device issues a corresponding signal to the control device. Where electric toothbrushes are used, it is possible, for example, for the motor speed to be reduced from the usual speed for adults when a child is the user, so that a gentler tooth cleaning operation is performed for the child. In addition, the control device may vary, responsive to a signal from the coding detection device, the duration of a timer according to the user identified, setting the timer to two minutes for children and to three minutes for adults, for example. The type of timer signal could also be modified, as by selecting a tune for children and a buzzer tone for adults.
In a further aspect of the invention it is also possible to store, process and indicate as on a display user-specific data such as cleaning frequency, cleaning speed, cleaning time, time interval between cleaning operations or application pressure automatically in response to a corresponding signal from the detection device. This too results in enhanced user comfort.
The handle section hence detects, i.e., identifies, the individual user indirectly by referring to the cleaning tool used or its coding because each user is assigned to one or more cleaning tools of his or her own. For this purpose the cleaning tools, which otherwise may be of identical construction, may have user-specific coding elements.
Provision may also be made for a specific function control in dependence upon the particular type of cleaning tool used. For instance, operating parameters of the handle section may be varied automatically when a brush attachment with specific properties such as high or low hardness is used. Equally, another operating program may be run when a cleaning tool of different type as, for example, an interproximal cleaning tool, a tool for gum massage or a tongue cleaner is attached to the handle section. Rotational speed, desired cleaning time, driving motion, cleaning frequency, cleaning speed, application pressure threshold value, etc. can be suitably adapted in response to the individual cleaning tool and/or user.
Still further, by identifying an individual cleaning tool it is possible to establish its state of wear, for example, by determining and evaluating the time of past uses or cleaning operations of this particular cleaning tool. Where cleaning tools with chemical additives are used, their “use by” date can be identified by the date of manufacture hidden in the coding. Predetermined cleaning or maintenance intervals can also be indicated.
A variety of approaches are possible for the detection of the coding provided directly on the cleaning tools as well as the coding of the cleaning tools.
In particularly simple manner the cleaning tool is coded by its shape. It may possess one or several shaped bodies which are connected to the body of the cleaning tool fixedly or formed integrally therewith and lie in the range of detection of the coding detection device of the handle section when the cleaning tool is coupled to the handle section. The coding may embody a specific geometrical outer contour and/or a specific spatial arrangement of the shaped body relative to the coupling section of the cleaning tool and ultimately to the coding detection device on the handle section. Detection of the shaped body or bodies may be performed in noncontacting fashion using, for example, light barriers or the like.
In an embodiment of the invention the coding device of each cleaning tool is brought into mechanical contact with the coding detection device, enabling it to read the coding. This results in a particularly straightforward construction.
The handle section may include a scanning device for scanning the coding provided on the respective cleaning tool being used.
Preferably the handle section may include a movable or deformable sensing element which is moved or deformed by the mechanical coding of the cleaning tool as the latter is being seated onto the handle section. Depending on the coding, the sensing element is moved or deformed by a predetermined amount or in a predetermined direction. The sensing element produces a signal responsive to the movement or deformation so that the coding can be detected. The sensing element may also be configured in such manner that it senses a force that the coding exerts as the cleaning tool is being seated onto the handle section. This can be accomplished, for example, by a piezoelectric design of the sensing element in which the sensing element is active itself to deliver a signal. To obtain a particularly simple configuration the sensing element may be constructed as a preferably electromechanical contact member. This member, upon being correspondingly deformed or moved by the coding of the cleaning tool, then opens or preferably closes one or several contacts so that a corresponding signal is produced.
The sensing element may be configured in such a manner that it is deformed to different degrees or moved in different directions responsive to the coding of the attached cleaning tool, correspondingly closing different contacts or a different number of contacts.
In a further aspect of the invention provision is made for several sensing elements so that different codifications of the cleaning tools cause different sensing elements or a different number of sensing elements to be actuated.
The sensing element or the sensing elements may be arranged so as to be freely accessible. In this arrangement the sensing element may be brought into operative association directly with a corresponding coding element of the cleaning tool. In an advantageous embodiment of the invention the sensing element is indirectly actuatable. The sensing element may be disposed in the interior of a housing of the handle section which may have a deformable portion, for example in the form of a soft plastic portion, through which the sensing element can be actuated. This enables a sealed, in particular fluid-tight construction of the handle section to be obtained.
In another advantageous embodiment of the invention the coding detection device may include a movable probe element which is moved by the coding of the cleaning tool during its seating engagement with the handle section. The coding detection device includes a motion sensor that detects the movement of the probe element advantageously in terms of amount and/or magnitude. The different coding of different cleaning tools is preferably designed so as to effect movements of the probe element of different magnitude and/or in different directions as the cleaning tool is being attached to the handle section. Provision may be made for several probe elements so that individual probe elements or different combinations of probe elements can be actuated by differently arranged coding sections of the cleaning tools.
Various configurations are possible for the motion sensor. It may operate optically, for example, in the manner of a light barrier. It may also detect the force exerted on the probe element by a respective coding. Preferably a sensing element of the type described in the foregoing may find application, which in this case is actuated indirectly, that is, through the probe element.
A particularly advantageous embodiment of the invention resides in that the probe element is the drive shaft of the drive mechanism arranged in the handle section for driving the cleaning tool. The drive shaft may be mounted in longitudinally displaceable fashion so that it is pushed into the interior of the handle section by the coding of the cleaning tool as it is being seated onto the handle section. The use of the drive shaft as probe element obviates the need for any specific additional arrangements with regard to the sealing of the handle section.
As coding the cleaning tool preferably has an actuating surface, in particular a pressure application surface, which is constructed and arranged such as to make engagement with an engagement surface of the coding detection device when the cleaning tool is seated onto the handle section, exerting a defined effect on said surface. The actuating surface and the engagement surface thus form interacting surfaces. Provision may be made for actuating surfaces of different coding to exert different effects on the same engagement surface, moving it, for example, a greater or lesser amount. Provision may further be made for different actuating surfaces to act on different engagement surfaces, thereby enabling the coding to be read. The engagement surface on the handle section may be disposed directly on the sensing element previously described or, alternatively, on the probe element likewise described in the foregoing or like reacting member, in particular on the drive shaft of the handle section. In the last mentioned instance the actuating surface is preferably provided on a drive shaft section of the drive shaft provided in the cleaning tool. This arrangement is particularly advantageous because it makes use of the already existing coupling sections provided for the coupling of cleaning tool and handle section to detect the respective cleaning tool, thus obviating the need to provide and process additional mechanical coupling sections. The coupling section on the cleaning tool is coded by means and in the form of an actuating surface or coded differently to exert a defined effect, particularly a defined actuating motion, on the coupling section of the handle section, which for this purpose is provided with a corresponding engagement surface.
In another advantageous embodiment of the invention the coding detection device is of the noncontacting type. This has the advantage of avoiding malfunctions due to contaminated contact surfaces or wear resulting from frequent attachment and disengagement operations.
According to a further aspect of the invention the handle section may include a signal receiver or reacting member for receiving a coded signal from the cleaning tool. The handle section may also possess a signal transmitter or acting member emitting an interrogation or activation signal to the cleaning tool which responds by sending the coded signal back. The emission of the coded signal by the cleaning tool may take place actively by a corresponding signal transmitter. The possibility also exists for passive reflection to take place on the cleaning tool, which produces a corresponding coding of the signal.
The coding of the cleaning tools and the corresponding detection of such coding may be implemented in a further variety of ways. According to a preferred embodiment of the invention provision is made for a magnetic sensor that detects a magnetic coding of the respective cleaning tool attached to the handle section. The magnetic coding of the cleaning tool may take place by introducing an individually different number of magnetic particles as acting member into a portion of the cleaning tool. The magnetic sensor may be of different configurations. According to a preferred embodiment of the invention the handle section includes as reacting member a Hall sensor that provides an electrical signal corresponding to the magnetic coding of the respective cleaning tool. According to a further preferred embodiment of the invention the handle section may include an LC oscillator which is detuned by the magnetic coding of the attached cleaning tool, thus supplying different frequencies assignable to the individual users.
Another advantageous embodiment of the invention resides in the provision of reed contacts on the handle section which are actuated individually when the cleaning tools are attached to the handle section. Depending on the combination of contacts actuated, a specific user can be identified. In accordance with an advantageous embodiment of the invention provision may be made for an optical sensor for detecting an optical coding of the respective cleaning tool attached to the handle section. As optical coding a color code may be provided on the cleaning tool which is identified by a color sensor.
Advantageously the handle section may also be equipped with one or several optical waveguides exiting from the handle section and emitting an optical signal. The light signal delivered to the cleaning tool is coded by the tool and returned to the handle section which receives this coded signal by means of a corresponding sensor or detector and converts it, receiving it by means of corresponding optical waveguides and transmitting it to a corresponding sensor. The coding may take place by defined interruption or partial obstruction of the optical waveguides exiting from the handle section. Moreover, the light exiting from the handle section through the optical waveguide can be reflected differently by the toothbrush. A specific user can be identified depending on the intensity of the reflection.
According to another preferred embodiment of the invention provision may be made for a capacitive sensor for detecting a capacitive coding of the respective cleaning tool attached. In particular the handle section may have two or more capacitor plates whose capacitance is varied by the introduction of a dielectric provided on the cleaning tool. The coding of the cleaning tools may be performed by different dielectric portions on the respective cleaning tool. A specific user is then identifiable in accordance with the variation in capacitance.
In a further advantageous embodiment of the detection device provision is made for a preferably electrically operating sensor for detecting an electrical coding of the respective cleaning tool attached. The cleaning tool sends a coded electrical signal to the handle section, meaning to a signal receiver provided thereon, thus enabling the respective user or the respective cleaning tool to be identified. It is also possible for the handle section to send initially an interrogation signal to the cleaning tool, which signal is coded by the cleaning tool and subsequently sent back.
In a further aspect of the invention provision may be made for a radio device for detecting the respective cleaning tool attached by means of electromagnetic waves. In particular a transponder may be associated with the cleaning tool. The handle section initially emits electromagnetic waves for energy supply to the transponder. The transponder stores the energy and sends an individual identification back to a detector in the handle section which detects it and correspondingly identifies the respective user or cleaning tool. The characteristic features of the cleaning tool thus include the provision of a magnetic, electrical, capacitive, electromagnetic and/or mechanical coding device. Another characteristic feature may include the provision of a signal receiver for receiving a signal from the dental cleaning device and a signal transmitter for transmitting a coded signal to the dental cleaning device, with a coding device being inserted between the signal receiver and the signal transmitter for coding the received signal.
The coding device is preferably constructed as an integral part of the cleaning tool. However, it can also be designed as a separate component suitable for detachment from the remaining part of the cleaning tool or for replacement. This affords the advantage of requiring only a single mold for the manufacture of the cleaning tool. By mounting the separate coding device the cleaning tools are coded on an individual basis and assignable to a particular user.
The coding device is arranged preferably in the area of the connection between the cleaning tool and the handle section. This facilitates the reading of the coding by the coding detection device on the handle section. In particular the coding device may be integrated in a ring arranged at the end of the cleaning tool close to the handle section, being in particular snap-fittable thereto by positive engagement therewith. The various configurations of the coding detection devices may be provided singularly or in combination. The same applies to the various configurations of the coding device on the cleaning tool.
In summary, the present invention provides an electromotive toothbrush comprised of a handle section and one or more user-specific attachments as, for example, brush attachments or the like, with the handle section and the brush attachment fitted to the handle section communicating with each other. The brush sections or cleaning tools may be of various designs including, for example, a child's toothbrush with soft bristles, an adult's toothbrush with hard bristles, an interproximal brush or the like, with each of these cleaning tools of different design for the intended application being assigned to a specific user. Hence a handle section usable by each user is provided, onto which user-specific cleaning tools of like or different design are plugged in order to care for or clean the respective user's teeth by means of the user-specific cleaning tool(s). The cleaning tools have an acting member or a coding communicating with a reacting member or a coding detection device in the handle section. Thus, by suitably designing the acting member(s) or coding device in the cleaning tool it is possible to inform the handle section, by way of communication between the coding device and the coding detection device, which user-specific cleaning tool, be it an interproximal cleaning tool, a toothbrush or some other cleaning tool, is currently plugged on the handle section. This possibility of detecting the user-specific or cleaning-tool-specific data of the particular cleaning tool attached to the handle section provides the prerequisite for the handle section to be able to operate the attached cleaning tool on a user- or cleaning-tool-specific basis. Thus it is possible to set, for example, the cleaning period, the cleaning speed or similar cleaning-specific parameters on a user- and cleaning-tool-specific basis by means of the handle section. Furthermore it is possible to detect user- or cleaning-tool-specific data in terms of the cleaning operation, which data can be stored, for example, in user- or cleaning-tool-specific memories of the handle section or can be indicated on a display. The present invention not only protects a method of detecting the respective cleaning tool attached to the handle section of the electric toothbrush on a user- or cleaning-tool-specific basis, but also the handle section of the electromotive toothbrush as well as the related cleaning tool, with each of the last-mentioned items being considered singularly.
Further objects, advantages, features and application possibilities of the present invention will become apparent from the subsequent description of several embodiments illustrated in the accompanying drawings. It will be understood that any features described and/or represented by illustration, whether used singularly or in any meaningful combination, form the subject-matter of the present invention, irrespective of their summary in the claims or their back reference.



In the drawings,
FIG. 1 is a perspective view of an electric toothbrush having a handle section and a brush attachment attachable thereto;
FIG. 2 is a schematic longitudinal sectional view of the handle section of the electric toothbrush of FIG. 1, showing arranged in the housing thereof the drive motor with gearing and drive shaft, the storage battery for the drive motor and the charging module for the storage battery;
FIG. 3 is a schematic view of an electric toothbrush, showing a magnetic coding of the brush attachment and a Hall sensor for detecting the coding according to a preferred embodiment of the invention;
FIG. 4 is a sectional detail view of the toothbrush of FIG. 3, showing the arrangement of the Hall sensor and the magnetic coding of the brush attachment which is coupled to the handle section;
FIG. 5 is a schematic view of an electric toothbrush having a magnetically coded brush attachment and an LC oscillator in the handle section to detect the coding according to a further preferred embodiment of the invention;
FIG. 6 is a sectional detail view of the toothbrush of FIG. 5, showing the arrangement of the LC oscillator and the magnetic coding of the brush attachment which is coupled to the handle section;
FIG. 7 is a schematic view of an electric toothbrush having a magnetically coded brush attachment and a handle section with reed contacts to detect the coding according to a further preferred embodiment of the invention;
FIG. 7A is a schematic view of the magnetic material located on the circumference of the slip-on ring shown in FIG. 7;
FIG. 8 is a sectional detail view of the toothbrush of FIG. 7, showing the arrangement of the reed contacts and the magnetic coding of the brush attachment which is coupled to the handle section;
FIG. 9 is a schematic view of an electric toothbrush having an optically coded brush attachment and a handle section with optical waveguides according to a further preferred embodiment of the invention;
FIG. 9A is a schematic view of the optical waveguides provided on the slip-on ring shown in FIG. 9;
FIG. 10 is a sectional detail view of a toothbrush similar to FIG. 9, showing the arrangement of a light emitter and a light detector in the handle section and a coding of the brush attachment in the form of an optical waveguide, with the brush attachment and the handle section being shown in coupled condition;
FIG. 11 is a top plan view of the optical waveguides at the end, close to the handle section, of the brush attachment of FIG. 10;
FIG. 12 is a sectional detail view of a toothbrush similar to FIG. 10, showing the arrangement of a light emitter and a light detector in the form of a single integrated component in the handle section and a coding of the brush attachment in the form of an optical waveguide, with the brush attachment and the handle section being shown in coupled condition;
FIG. 13 is a schematic view of an electric toothbrush having an optically coded brush attachment and a handle section with color sensor for identification of the coding of the brush attachment according to a further preferred embodiment of the invention;
FIG. 14 is a sectional detail view of the toothbrush of FIG. 13, showing the arrangement of the color sensor in the handle section and the color code of the brush attachment which is coupled to the handle section;
FIG. 15 is a schematic view of an electric toothbrush having a brush attachment coded mechanically by its shape in accordance with another preferred embodiment of the invention;
FIG. 16 is a perspective view of the toothbrush of FIG. 15, showing the brush attachment as it is being coupled to the handle section;
FIG. 17 is a sectional detail view of the toothbrush of FIGS. 15 and 16, showing the arrangement of the coding projections on the brush attachment and the sensing elements in the form of electromechanical contacts for sensing the coding projections, with the brush attachment and the handle section being shown in coupled condition;
FIG. 18 is a schematic view of an electric toothbrush having an electromagnetically coded brush attachment with a transponder bonded thereto by adhesion and a corresponding detection device in the handle section according to a further preferred embodiment of the invention;
FIG. 18A is a schematic view of the transponder contained in the slip-on ring shown in FIG. 18;
FIG. 19 is a perspective view of the toothbrush of FIG. 18;
FIG. 20 is a sectional detail view of a toothbrush similar to FIGS. 18 and 19, showing the arrangement of a transponder chip in a coding ring provided at the end of the brush attachment, and a transmitter coil and a receiver coil together with an associated electronic evaluation device in the handle section, with the brush attachment and the handle section being shown in coupled condition;
FIG. 21 is a schematic view of an electric toothbrush having a capacitively coded brush attachment and capacitor plates in the handle section to detect the coding of the brush attachment according to a further preferred embodiment of the invention;
FIG. 22 is a detail view, in longitudinal section, of the toothbrush of FIG. 21, showing the arrangement of the dielectric portion of the brush attachment and the capacitor plates in the handle section, with the brush attachment and the handle section being shown in coupled condition;
FIG. 23 is a detail view, in cross section, of the toothbrush taken along the line A-A of FIG. 22, showing the arrangement of the dielectric portion of the brush attachment and the capacitor plates in the handle section;
FIG. 24 is a sectional view of a handle section having a longitudinally displaceable drive shaft and an electromechanical sensing element for detecting the displacement of the drive shaft according to a further preferred embodiment of the invention; and
FIG. 25 is a sectional view of the handle section of FIG. 23, showing the brush attachment in coupled condition.



The electric toothbrush shown in the Figures has a handle section 1 with a closed housing 26 accommodating, among other components and as illustrated in FIG. 2, in a manner known in the art an electric motor 23, a storage battery 24 adapted to be coupled to a charging station through a charging module 25 disposed at the bottom, and a control device 27 which may possess a printed circuit board or microprocessor. Various brush attachments 2 are seatable upon the end of the handle section 1. By means of a coupling device 3 the brush attachment 2 can be mechanically coupled to the handle section 1 in order to transmit the driving motion of the electric motor to the bristle head 4 of the brush attachment 2. The coupling device 3 comprises a positive-engagement element for positioning the cleaning tool body in its proper location and, in addition, a drive coupling which transmits the driving motion of the drive to the bristle head of the brush attachment. Protruding from the end of the handle section 1 is a drive shaft 28 adapted to be driven by the drive motor 23 via a gearing 29 in a manner equally known in the art. The drive shaft 28 has a coupling section 30 adapted to receive by positive engagement therewith a complementary coupling section of a drive shaft arranged in the cleaning tool 2, so that the driving motion is transmitted, enabling the bristle head 31 of the brush attachment to be driven in an oscillating manner.
To identify the individual brush attachment 2 when attached, provision is made on the handle section for a coding detection device 5. According to FIG. 3 a Hall sensor 6 is provided at the coupling end of the handle section 1 in order to read, meaning identify, a magnetic coding 7 on the brush attachment 2. The magnetic coding 7 is formed by a slip-on ring 8 provided at the coupling end of the brush attachment 2. The slip-on ring 8 is available in a variety of colors containing, depending on the color, a different number of magnetic particles or magnetic bodies differing in number, magnetic orientation and/or magnetic field strength. As FIG. 4 shows, the slip-on ring 8 may be positioned in its proper location on the body of the brush attachment advantageously by positive engagement therewith, being in particular snap-fitted thereto. This connection may be constructed such that the ring 8 is securable to the body of the brush attachment in only one predetermined orientation relative thereto. The Hall sensor 6 in the handle section 1 supplies a signal correlating with the number of magnetic particles or the arrangement of the magnetic bodies, the value of this signal identifying the respective brush attachment 2, and hence a specific user, and being suitable for further processing by the control device in the handle section 1. The color of the slip-on ring 8 makes it easy to remember which brush attachment 2 is assigned to which user.
As FIG. 4 shows, the magnetic coding 7 and the Hall sensor 6 are disposed at the coupling ends of the brush attachment and the handle section, respectively, lying advantageously opposite each other in order to enable an accurate detection to be accomplished.
The electric toothbrushes according to the further embodiments illustrated in FIG. 5 ff. are constructed basically in the same way as the toothbrush illustrated in FIGS. 1 and 2, so that like components are assigned like reference numerals, and the subsequent description deals only with the different implementations of the coding 7 of the brush attachments 2 and the corresponding coding detection devices 5 on the handle section 1. In the electric toothbrush illustrated in FIGS. 5 and 6 the brush attachment 2 carries likewise a slip-on ring 8 which is available in various colors and contains magnetic particles differing in number depending on the color. To detect the magnetic coding of the brush attachment 2, the coding detection device 5 has an LC oscillator 9 which is disposed at the coupling end of the handle section 1 and detuned by the magnetic material in the brush attachment 2, thereby supplying different frequencies assignable to the brush attachments or its users. The corresponding frequency signals are further processed by the control device in the handle section 1 in order to set the corresponding operating parameters or to process and indicate the user-specific data.
As FIG. 6 shows, the LC oscillator has a coil 136 and a capacitor 32 that are both disposed in the coupling end region of the handle section. The coil is arranged directly at the end. It may be mounted on a shoulder or the like of a handle section chassis. The capacitor is positioned under-neath the coil which faces the slip-on ring 8. This enables the coding to be detected with precise accuracy.
FIG. 7 shows a further embodiment of an electric toothbrush in which the slip-on ring 8 of the brush attachment 2 is provided with magnetic material only at defined locations on its circumference (cf. FIG. 7a). The coding detection device 5 comprises reed contacts 10 (cf. FIG. 8) arranged in the handle section 1 at the handle end close to the coupling device 3. When the brush attachment 2 is seated down onto the handle section 1, defined actuation of the reed contacts 10 takes place in accordance with the magnetic coding of the slip-on ring 8. Depending on the combination of contacts actuated, a specific user can be identified. Here too, the slip-on ring 8 is a colored ring to make it easier for the user to identify his or her assigned brush.
For enhanced response of the reed contacts, the magnetic ring 8 and the reed contacts 10 have their respective ends in relative opposite arrangement.
FIG. 9 illustrates an embodiment of an electric toothbrush in which the brush attachment 2 is detected optically. The coding detection device 5 comprises in the handle section 1 one or several optical waveguides 11 exiting at the coupling end of the handle section and experiencing defined interruptions or partial obstructions by the brush attachment 2. The brush attachment 2 returns the light signal emitted from the optical waveguides 11 to the handle section 1 in coded form, the coded light signal being directed through optical waveguides 12 to a sensor 13 which detects whether and in which intensity light was returned and issues a corresponding recognition signal enabling the brush attachment to be assigned to a user. For coding and returning the light signal the brush attachment 2 may possess a preferably likewise colored slip-on ring 8 in which corresponding optical waveguides 14 are provided (cf. FIG. 9a). According to a further variant the light emitted from the handle section 1 through the optical waveguide 11 is reflected individually by the brush attachment 2 or a correspondingly coded slip-on ring 8. Depending on the intensity of reflection a particular user can be identified.
FIGS. 10 and 11 illustrate an advantageous variant of the toothbrush of FIG. 9 with optical coding of the brush attachment and corresponding detection of the coding by the handle section 1. Provided in the handle section 1 directly at its coupling end are a light emitter 33 and in circumferentially offset position a light detector 34 which, through a light exit opening 35 and a light entrance opening 36 provided at the end of the handle housing 26, look at the coupled brush attachment 2. The light exit and light entrance openings may be closed by a transparent material to obtain a closed construction of the housing 26. Both the emitter 33 and the detector 34 are connected to the control and evaluation device 27 of the handle section 1. As FIG. 11 shows, the slip-on ring 8 of the brush attachment 2 accommodates an optical waveguide 37 receiving the light emitted by the emitter 33 through a light entrance opening 38 (cf. FIG. 10), coding it and returning it through a light exit opening 39 in the slip-on ring 8 to the detector 34 in the handle section. The light may be guided in a variety of ways, particularly by reflection. In this case the optical waveguide may be configured as a reflector. The signal issued by the light detector can be evaluated by the control device of the handle section 1 to identify the respective brush attachment. The optical waveguide 37 extends in the slip-on ring 8 in an approximately arcuate configuration (cf. FIG. 11). To increase the possibilities of coding, multiple light processing devices may be provided. FIG. 11 shows a second optical waveguide 40. Coding may be performed by selection of a particular one of multiple light detectors to which the respective optical waveguide returns the received light. Coding may also be performed by the optical waveguides modifying or processing the received light in different ways, in particular reflecting it in different intensities. This is then converted into a corresponding signal by the light detector.
FIG. 12 shows a further variant of optical coding. The light emitter 41 and the light detector 42 are constructed as an integral component. A partition wall 43 is preferably provided to separate the light entrance and light exit openings from each other. The light may be coded in particular by different magnitudes of reflection.
The embodiment of an electric toothbrush illustrated in FIGS. 13 and 14 has similar to the preceding embodiments a colored slip-on ring 8 at the end of the brush attachment 2 close to the coupling section 30. The handle section 1 has as recognition device 5 a color sensor 15 disposed at the coupling end of the handle section 1 and oriented in the direction of the colored slip-on ring 8. The color sensor 15 detects the color of the slip-on ring 8, enabling the respective brush attachment or user of the toothbrush to be determined. Conveniently, the color sensor is arranged directly at the coupling end of the handle section 1 and oriented in the direction of the ring 8 when the brush attachment sits on the handle section 1. The color of the slip-on ring 8 preferably has fluorescent properties or other properties increasing the light intensity, thereby enabling the color of the slip-on ring 8 to be recognized by the color sensor 15 reliably.
FIGS. 15, 16 and 17 illustrate an embodiment of an electric toothbrush in which the brush attachments 2 are recognized mechanically. The colored slip-on ring 8 at the end of the brush attachment 2 is an individually shaped coding body having projections 16 or recesses in the form of ribs or grooves. According to one embodiment of the invention the shaped bodies extend as projections from the end of the brush attachment, in particular essentially parallel to the longitudinal axis of the brush attachment. At the opposite end of the handle section 1 provision is made for elastically deformable sensing elements in the form of mechanical contacts 17 which are subjected to individual and defined actuation by the brush attachment 2, meaning the projections 16 on the slip-on ring 8, so that the respective brush attachment 2 is identified according to the combination of actuated contacts. The shaped coding bodies 16 have for this purpose actuating or pressure application surfaces which are arranged, oriented and/or configured such as to depress the sensing element a predetermined amount when the brush attachment is seated down on the handle section. The sensing elements generate a signal responsive to the amount of depression, in the simplest case an on-off signal according to the contacting of the contact sections provided at the sensing elements' ends. Actuation of the mechanical contacts 17 can be checked preferably electrically. To cover the mechanical contacts 17 and shield them against the environment a soft membrane 18 may be placed over the mechanical contacts 17 at the end of the handle section 1, through which membrane the mechanical contacts 17 can be actuated by the projections 16. To accomplish this the housing 26 may be a two-component injection molded part fabricated from hard and soft plastics material.
FIGS. 18 to 20 illustrate a further embodiment of an electric toothbrush in which the respective brush attachment 2 is detected, i.e., identified by means of radio signals. The brush attachment 2 is equipped with a transponder 19 which may be bonded by adhesion to the brush attachment 2 in the form of a label referred to as smart label (FIG. 19). Advantageously, the transponder 19 may also be contained in the colored slip-on ring 8 at the end of the brush attachment 2 (cf. FIGS. 18a and 20). Provided in the handle section 1 is a detector 20 tuned to the transponder 19 and serving as both a signal transmitter and a signal receiver. Via the coil 45 the detector 20 in the handle section 1 initially emits electromagnetic waves to the coil 44 connected to the transponder 19 in order to supply power to the transponder 19 or its microchip. The transponder stores the energy and sends a specific identification back to the detector 20 which receives said identification, identifies it by means of its electronic evaluation device 46 and delivers a corresponding signal to the control device 27 of the handle section 1. The coils 44 and 45 hence serve as both transmitter and receiver facility. They are disposed in relative opposite arrangement at the ends of the brush attachment 2 and the handle section 1, respectively (cf. FIG. 20). The identification sent back by the transponder 19 enables the brush attachment 2, and hence its user, to be identified.
In the embodiment of an electric toothbrush illustrated in FIGS. 21, 22 and 23, identification of the brush attachment 2 is performed capacitively. Provided in the handle section 1 are two or more capacitor plates 21 between which a dielectric 22 is insertable to vary the capacitance of the capacitor formed by the capacitor plates 21. The dielectric 22 is arranged at the end of the brush attachment 2, and it may be in particular part of a slip-on ring 8 fittable to the brush attachment 2. The dielectric portion 22 extends preferably approximately parallel to the longitudinal axis of the brush attachment, approximately parallel to its circumferential surface. Provided in the circumferential surface of the handle housing 26 is an indentation 47 open towards the end and having the form of a longitudinally parallel groove suitable for engagement by the dielectric portion 22 of the brush attachment as it is being coupled to the handle section 1. The capacitor plates 21 are disposed in the interior of the housing 26 on either side of the indentation referred to so that the dielectric comes to lie between the capacitor plates. The use of different dielectrics makes it possible to code the brush attachments 2 individually. Depending on the capacitance or the variation in capacitance by the different dielectrics, the corresponding brush attachment 2 and hence its user can be identified. In an arrangement involving several capacitors, a coding is also obtainable by the arrangement and/or number of dielectrics.
FIGS. 24 and 25 illustrate a specific embodiment of the invention involving a brush attachment coded mechanically, that is, by its shape, and a mechanical detection of this coding. The coding of the brush attachment is part of its coupling section 48 used for coupling the drive train 49 in the brush section with the drive shaft 28 in the handle section, to be more precise, with the coupling section 30 thereof. As FIG. 25 shows, the body of the brush attachment is seated onto a brush mount 50 of the handle section 1 with an exact fit so that the brush attachment sits firmly on the handle section 1. By means of detent noses and corresponding recesses the brush attachment is secured in place by making positive engagement with the handle section, that is, its brush mount. Axial securing can be accomplished also by frictional engagement. When the brush attachment is pushed onto its mount, the coupling sections 48 and 30 in the drive train also make interfitting engagement. The coupling sections are formed by a shaft stub and a complementary recess in the form of a blind-end hole in the opposite shaft end, thus enabling the shaft stub to be an exact fit within the blind-end type shaft bore. Torque transmission takes place preferably by positive engagement.
The coupling sections have complementary mating surfaces 51 and 52, preferably in the form of a flattening on the drive shaft 28 and a corresponding bore secant surface in the recess 53 of the drive shaft portion 54 of the brush attachment. A spline or a splined-shaft profile may also be provided for torque transmission.
The brush attachment, in particular the coupling section 48, has as coding an actuating surface 55 which in coupled condition is in engagement with an associated engagement surface on the handle section 1, in particular on the coupling section 30 of the drive shaft 28. The actuating surface 55 mates with the engagement surface 56 in such manner that a predetermined interaction occurs between these two surfaces in coupled condition. In particular the actuating surface 55 is arranged and aligned so as to exert a predetermined pressure on the engagement surface 56. To be able to read or scan the configuration of the actuating surface 55, the associated engagement surface 56 is formed on a movable probe element, producing as interaction a predetermined movement of the probe element. It will be understood that it is also possible to detect a force, but a movement can be detected with greater ease. Different configurations of the actuating surfaces 56 are translated into different movements of the associated engagement surface 56 of the probe element.
As probe element the drive shaft 28 of the handle section is advantageously used. The drive shaft is mounted longitudinally displaceably and preferably biased into protrusion from the handle section by means of biasing members. When the brush attachment 2 is seated down on the handle section the brush attachment's actuating surface 55 urges the drive shaft 28 a predetermined distance into the interior of the handle section 1. The displacement is detected by a motion sensor which may embody a variety of configurations, being operable for example as a light barrier. Other displacement sensors may also be employed. Preferably provision may be made for an elastically deformable sensing element with electromechanical contact of the type previously described with reference to FIG. 17. The drive shaft 28 preferably sits with a lug, preferably with its end remote from the coupling section 30, on the sensing element 57. The sensing element may at the same time serve as biasing member. When the drive shaft 28 is pressed down, the sensing element produces a corresponding signal, in particular opening or closing a corresponding contact. By suitably constructing the sensor or sensing element or multiple sensing elements the coding of the brush attachment can be read.
As FIG. 25 shows, the actuating surface 55 is formed by the bottom surface of the blind-end type recess 53 in the brush attachment's drive shaft. The associated engagement surface is formed by the end of the drive shaft 28. While being reversible, this arrangement is preferably configured as illustrated.
Alternative embodiments of the actuating and engagement surfaces 55 and 56, respectively, are possible. In a further aspect of the invention provision may be made for conical mating surfaces. Other configurations may also be contemplated.

## Claims

1. A handle of an electrical dental cleaning device for use with a cleaning attachment, the handle comprising:
a coupling configured to releasably connect a cleaning attachment to the handle;
a drive shaft extending outwardly from the coupling and arranged to drive at least a portion of a cleaning attachment;
an electric motor operatively connected to the drive shaft;
a receiver or transceiver for non-contacting reception of electromagnetic energy from a coupled cleaning attachment; and
an electronic control device that inhibits operation of the motor in response to the receiver or transceiver receiving electromagnetic energy transmitted by a coupled cleaning attachment,
wherein the receiver or transceiver comprises a coil.

2. The handle according to claim 1, wherein the receiver or transceiver receives electromagnetic energy emitted by a cleaning attachment only when a cleaning attachment is mechanically coupled to the handle.

3. The handle according to claim 1, wherein the receiver or transceiver is disposed adjacent to the coupling device.