Personal care device drive unit

Abstract

A personal care device drive unit, a personal care system and a method for detecting which of a set of different functional units is attached to the personal care device drive unit using a combination of: at least one parameter related to a measured electric current in a motor of the personal care device drive unit, at least one parameter relating to a measured vibration of a main body of the personal care device drive unit, and at least one parameter of a magnetic field measured by a magnetic field sensor at a fixed location in the main body of the personal care device drive unit. At least one of the set of different functional units includes a functional unit having an integrated magnetic field modifier which modifies a magnetic field detectable at the fixed location in the main body into a pre-determined value.

Description

[0001] 2024PF00148

[0002] 1

[0003] PERSONAL CARE DEVICE DRIVE UNIT

[0004] FIELD OF THE INVENTION

[0005] This invention relates to the field of personal care devices which have a main body which is connectable with each functional unit of a set of different functional units, and wherein the device comprises a functional unit detection logic for detecting which functional unit of the set of different functional units is connected to the main body of the personal care device.

[0006] BACKGROUND OF THE INVENTION

[0007] One known class of personal care devices includes a main body to which each functional unit of a plurality of different functional units is selectively attachable by a user for providing a range of different personal care functions.

[0008] There is value in automatically detecting which functional unit of the set of different functional units a user has selected and attached to the main body of the device without the need for the user to manually enter this information to the device using a user interface.

[0009] It is known to use electronic detection mechanisms which detect which functional unit is attached using dedicated electrical identification signals passed from the functional unit to the main body of the personal care device. However, these require additional circuitry to be included in the functional unit specifically for this purpose which adds to the cost and complexity of the functional unit. This is disadvantageous, particularly since the functional units may sometimes be consumable parts which are replaceable at intervals. Other methods may involve the use of electronic or optical tags on the functional unit, readable by a suitable reading component in the main body of the personal care device, e.g. RFID tags or barcodes. However, this also adds complexity to the functional unit, and requires addition of dedicated tag-reading components in the main body.

[0010] A preferred way of detecting which functional unit of the set of different functional units is attached to the main body of the personal care device is to probe intrinsic operational characteristics of the personal care device which vary in a known and reliable way in dependence on which of the functional units is being used. For example, it is possible to probe properties and characteristics of operational components which are present in a personal care device in order to infer which functional unit of the set of functional units has been attached to the main body. It is known, for example, to probe characteristics of the motor current in the main body to infer which of the set of functional units is attached to the main body. Different functional units may require motor currents of different values in order to be driven by the motor in the main body. 2024PF00148

[0011] 2

[0012] EP3855976B 1 in the name of the applicant discloses a personal care device having a main body wherein a motor is arranged. The main body has a connection interface adapted to enable connection of any selected one of a set of different functional units to the main body to enable driving of the selected one of the set of different functional units by the motor. The device has a controller configured to identify the selected one of the set of different functional units connected to the main body based on an electric current in the motor and a vibration of the main body, which are both measured by a dedicated sensor in the main body during driving of the selected functional unit.

[0013] Developments in the field have enabled provision of personal care devices with an expanded set of possible attachments available to a user. As the number of attachable functional units expands, it becomes more difficult to distinguish between the functional units based on intrinsic operational characteristics of the device.

[0014] SUMMARY OF THE INVENTION

[0015] The invention is defined by the claims.

[0016] In accordance with an aspect of the invention, there is provided a personal care device drive unit comprising: a main body; a motor arranged in the main body; a connection interface arranged on the main body and adapted to enable connection of any selected one of a set of different functional units to the main body so as to enable driving of a movable functional component of the selected one of the set of different functional units by the motor; a current sensor arranged for measuring at least one current parameter relating to an electric current in the motor when driving at least one of the set of different functional units when connected to the main body; a vibration sensor arranged in the main body for measuring at least one vibration parameter relating to a vibration of the main body during driving of at least one of the set of different functional units when connected to the main body; a magnetic field sensor mounted in a fixed position relative to the main body for measuring at least one magnetic field parameter relating to a magnetic field at a fixed location relative to the main body when at least one of the set of different functional units is connected to the main body; and a controller comprising a functional unit detection logic which is configured to receive a set of inputs and generate, using the set of inputs, an output signal associated with the selected one of the set of different functional units which is connected to the connection interface, wherein the set of inputs includes: a value of the magnetic field parameter measured by the magnetic field sensor, a value of the at least one current parameter measured by the current sensor, and a value of the at least one vibration parameter measured by the vibration sensor.

[0017] Different functional units of the set of different functional units may draw a different current from the motor, and different functional units of set of different functional units may induce a different pattern of vibrations in the main body of the personal care device. It is thus possible to distinguish between certain functional units based on probing these characteristics using the current sensor and the vibration sensor. However, certain functional units may overlap both in terms of the 2024PF00148

[0018] 3 current they draw and the vibration pattern they induce. In this case, it is difficult to distinguish these functional units apart from one another.

[0019] It is thus proposed in accordance with the invention to differentially detect which of the set of different functional units is connected to the main body by using a detection logic which utilizes as inputs all three of: current characteristics associated with the motor, vibration of the main body, and a magnetic field sensed at a fixed location in the main body by a magnetic field sensor. This provides an effective way of distinguishing between a potentially large number of different functional units which may for example be similar in terms of the motor current which is drawn and / or the vibration characteristics associated with their use. The additional utilization of magnetism adds a further variable which can be deliberately tuned in manufacture, for example by incorporation of magnetic field modifier components, e.g. magnetic sources, in at least a subset of the different functional units.

[0020] The magnetic field sensor is, for example, arranged for detecting an influence on said parameter of a magnetic field at said fixed location by a magnetic field modifier unit carried by at least one of the set of different functional units when said at least one of the functional units is connected to the connection interface of the main body.

[0021] The output signal generated by the functional unit detection logic is indicative of an identification of which of the set of different functional units has been connected to the connection interface of the main body, i.e. identification of the selected one of the set of different functional units. In other words, the controller is configured to differentially identify which of the set of different functional units is connected to the connection interface.

[0022] The functional unit detection logic may comprise a decision tree. The output signal generated by the functional unit detection logic may be a final decision output of the decision tree. The decision tree may comprise a set of decision nodes. The generating of the output signal by using a value of the magnetic field parameter measured by the magnetic field sensor, a value of the at least one current parameter measured by the current sensor, and a value of the at least one vibration parameter measured by the vibration sensor may mean that each respective one of said three values forms an input respectively to at least one decision node of the set of decision nodes comprised by the decision tree. In other words, in some embodiments, each respective one of: a value of the magnetic field parameter measured by the magnetic field sensor, a value of the at least one current parameter measured by the current sensor, and a value of the at least one vibration parameter measured by the vibration sensor, forms an input respectively to at least one decision node of the set of decision nodes comprised by the decision tree.

[0023] In some embodiments, the functional unit detection logic includes: at least a first detection pathway in which the output signal is generated in dependence upon the value of the at least one magnetic field parameter measured by the magnetic field sensor; and at least a second detection pathway in which the output signal is generated in dependence upon the value of the at least one current parameter measured by the current sensor and / or the value of the at least one vibration parameter measured by the vibration sensor. In these embodiments, the functional unit detection logic may be configured to 2024PF00148

[0024] 4 selectively follow the first detection pathway or the second detection pathway in dependence upon evaluation of a pre-defined condition or criterion.

[0025] In some embodiments, the functional unit detection logic may comprise a decision tree, the decision tree may comprise a first decision node, and the first detection pathway and the second detection pathway may each lead from the first decision node. The detection pathways may be respective branches of the decision tree. The pre-defined condition or criterion may be defined by the first decision node.

[0026] In some embodiments, the functional unit detection logic may be configured so as to selectively follow the first detection pathway or the second detection pathway in dependence upon: the measured value of the at least one magnetic field parameter; the measured value of the at least one current parameter; and / or the measured value of the at least one vibration parameter. For example, the previously mentioned pre-defined condition or criterion may be dependent upon the value of at least one of: the at least one magnetic field parameter, the at least one current parameter and the at least one vibration parameter. By way of example, the first and second detection pathways may lead from a first decision node, wherein the pre-defined condition or criterion is defined by the first decision node, and wherein the first decision node receives as input at least one of: the at least one magnetic field parameter, the at least one current parameter and the at least one vibration parameter.

[0027] By way of example, here the controller may sample a value of the at least one magnetic field parameter using the magnetic field sensor, a value of the at least one current parameter using the current sensor and / or a value of the at least one vibration parameter using the vibration sensor and, dependent upon the value(s), select to differentially identify the connected functional unit using the magnetic field parameter alone or by using the current and / or vibration parameters.

[0028] In some embodiments, the controller comprises a memory adapted to store a plurality of value ranges, and wherein the functional unit detection logic is configured to selectively follow the first detection pathway or the second detection pathway in dependence upon which value range of said plurality of value ranges the measured value of the magnetic field parameter, the measured value of the at least one current parameter and / or the measured value of the at least one vibration parameter falls into. In other words, evaluating said pre-defined condition or criterion (e.g. defined by the first decision node) may comprise evaluating which value range of said plurality of value ranges the measured value of the magnetic field parameter, the measured value of the at least one current parameter and / or the measured value of the at least one vibration parameter falls into.

[0029] In some embodiments, the controller further includes a pressure detection logic. The pressure detection logic may be configured to generate an additional output signal in dependence upon the value of the magnetic field parameter measured by the magnetic field sensor. The additional output signal may be associated with an external pressure exerted on at least one of the set of different functional units when said at least one of the set of different functional units is connected to the main body. In other words, the pressure detection logic may be configured to determine a measure of an external pressure 2024PF00148

[0030] 5 exerted on at least one of the set of different functional units when said at least one of the set of different functional units is connected to the main body, and determine said measure of an external pressure in dependence upon (or using) one or more values of the magnetic field parameter output by the magnetic field sensor.

[0031] Another aspect of the invention is a personal care system comprising a personal care device drive unit in accordance with the invention, and further comprising a set of different functional units, each being releasably connectable to the connection interface of the main body of the personal care device drive unit. Each of the different functional units may comprise a movable functional component. The personal care device drive unit may be a personal care device drive unit in accordance with any of the examples or embodiments detailed in this disclosure, or in accordance with any claim.

[0032] In the personal care system in accordance with the invention, at least one of the set of different functional units includes a magnetic field modifier. By way of example, in some embodiments, the magnetic field modifier is a magnetic field source. The personal care system in accordance with the invention is configured such that, when said at least one of the set of different functional units is connected to the main body, the magnetic field modifier modifies the value of the magnetic field parameter measured by the magnetic field sensor into a predetermined value.

[0033] In other words, the magnetic field modifier is associated with a defined magnetic signature which is detectable. For example, a ‘pre-determined value’ may mean a value that is established at the location of the magnetic field sensor once the functional unit has been connected to the connection interface.

[0034] Thus, according to this aspect of the invention, at least one of the set of different functional units may be detectable or identifiable based on detecting in the measured value(s) of the at least one magnetic field parameter the magnetic signature associated with the magnetic field modifier carried by the at least one of the set of different functional units.

[0035] As mentioned previously, in some embodiments, the controller comprises a memory adapted to store a plurality of value ranges. In these embodiments, the functional unit detection logic may be configured to selectively follow the first detection pathway or the second detection pathway in dependence upon which value range of said plurality of value ranges the measured value of the magnetic field parameter falls into. In some embodiments, the plurality of value ranges stored in the memory of the controller comprises a first value range into which the measured value of the magnetic field parameter modified by said magnetic field modifier falls.

[0036] In some embodiments, at least a first functional unit of the set of different functional units includes a first magnetic field modifier, and at least a second functional unit of the set of different functional units includes a second magnetic field modifier.

[0037] In these embodiments, the first magnetic field modifier may be configured to modify the value of the magnetic field parameter measured by the magnetic field sensor into a first predetermined value, and the second magnetic field modifier may be configured to modify the value of the magnetic 2024PF00148

[0038] 6 field parameter measured by the magnetic field sensor into a second predetermined value which is different from the first predetermined value.

[0039] In this set of embodiments, the set of different functional units includes at least two functional units which include different respective magnetic field modifiers, and wherein each magnetic field modifier is associated with a different magnetic signature. Accordingly, this allows for the two different functional units to be distinguished from one another and / or distinguished from other functional units in the set of different functional units using an output from the magnetic field sensor.

[0040] In some embodiments, the first magnetic field modifier comprises a first magnetic field source, and the second magnetic field modifier comprises a second magnetic field source.

[0041] In these embodiments, the first magnetic field source may have a first magnetic field polarity (- / +) measurable by the magnetic field sensor when the first functional unit is connected to the connection interface. The second magnetic field source may have a second magnetic field polarity (+ / -) opposite to the first magnetic field polarity and measurable by the magnetic field sensor when the second functional unit is connected to the connection interface. In other words, in some embodiments, the first magnetic field source and the first functional unit are configured so that, when the first functional unit is connected to the connection interface, a magnetic field generated by or associated with the first magnetic field source is detected at the magnetic field sensor as a contribution to the detectable magnetic field at the location of the magnetic field sensor having a first polarity. The second magnetic field source and the second functional unit may be configured so that, when the second functional unit is connected to the connection interface, a magnetic field generated by or associated with the second magnetic field source is detected at the magnetic field sensor as a contribution to the detectable magnetic field at the location of the magnetic field sensor having a second polarity, opposite to the first polarity.

[0042] This is a technically efficient configuration, since it provides for magnetic signatures associated with the two functional units which are easily distinguishable since they differ in terms of magnetic polarity. This enables a more robust distinction between the magnetic signatures of the two different magnetic field modifiers compared with, for example, two magnetic field sources which have a same polarity and differ only with respect to magnetic field strength.

[0043] As mentioned previously, in some embodiments, the controller comprises a memory adapted to store a plurality of value ranges. In these embodiments, the functional unit detection logic may be configured to selectively follow the first detection pathway or the second detection pathway in dependence upon which value range of said plurality of value ranges the measured value of the magnetic field parameter falls into. In some embodiments, the plurality of value ranges stored in the memory of the controller comprises: a first value range into which the measured value of the magnetic field parameter modified by said first magnetic field modifier falls, and a second value range into which the measured value of the magnetic field parameter modified by said second magnetic field modifier falls.

[0044] In some embodiments, the personal care system further includes a pressure sensing subsystem configured for sensing an external pressure exerted during use on at least one of the set of 2024PF00148

[0045] 7 different functional units when said at least one of the set of different functional units is connected to the main body. The pressure sensing subsystem may include a further magnetic field source mounted to the main body. The pressure sensing subsystem may further include a displacement system configured to generate a displacement of the further magnetic field source relative to the magnetic field sensor such that a distance between the further magnetic field source of the pressure sensing subsystem and the magnetic field sensor and, therewith, a magnetic field strength measured by the magnetic field sensor is dependent on said external pressure according to a predefined relation.

[0046] Thus, according to this set of embodiments, the magnetic field sensor which is used as part of the functional unit detection logic is also used for the function of performing pressure sensing during operation of the personal care device with at least one of the set of different functional units. This provides functional and structural efficiency, since two functions - pressure sensing and functional unit detection - are enabled using a shared component, namely the same magnetic field sensor.

[0047] As mentioned previously, current and vibration also represent two parameters that can be used in distinguishing between different functional units of the set of different functional units. In some embodiments, the set of different functional units comprises one functional unit which is associated with the occurrence in the main body of a maximum vibration amplitude above a predefined threshold value in a predefined range of vibration frequencies.

[0048] The set of different functional units may further comprise first and second further functional units which are each associated with the occurrence of a value of the at least one current parameter in, respectively, mutually different first and second predefined ranges of the value of the at least one current parameter.

[0049] In these embodiments, the second detection pathway may comprise generating, at a first decision node, an output signal associated with said one functional unit when a maximum vibration amplitude occurring within the predefined range of vibration frequencies and measured by the vibration sensor is above the predefined threshold value.

[0050] In these embodiments, the second detection pathway may further comprise generating, at a second decision node, an output signal associated with the first or the second further functional units when the value of the at least one current parameter measured by the current sensor is in, respectively, said first or said second predefined range of the value of the at least one current parameter.

[0051] The second decision node may be a subsequent decision node in a decision tree structure which forms the functional unit detection logic, or it might be a preceding decision node in a decision tree structure forming the functional unit detection logic.

[0052] In some embodiments, said one functional unit may comprise a functional component configured to perform a reciprocating motion. For a functional unit which exhibits a reciprocating motion, vibration may be an appropriate parameter to use to detect its connection to the main body and use since reciprocating motion has a reliable periodic aspect to the motion it induces in the main body of the 2024PF00148

[0053] 8 personal care device. In these embodiments, said first and second further functional units may each comprise a functional component configured to perform a rotating motion.

[0054] In one example set of embodiments, the set of different functional units may include two or more of the following: a first functional unit comprising a first magnetic field modifier which modifies the value of the magnetic field parameter measured by the magnetic field sensor into a first predetermined value when the first functional unit is connected to the connection interface; a second functional unit comprising a second magnetic field modifier which modifies the value of the magnetic field parameter measured by the magnetic field sensor into a second predetermined value, different from the first predetermined value, when the second functional unit is connected to the connection interface; a third functional unit which is associated with the occurrence in the main body of a maximum vibration amplitude above a predefined threshold value in a predefined range of vibration frequencies; a fourth functional unit associated with the occurrence of a value of the at least one current parameter in a first pre-defined range of the value of the at least one current parameter; and a fifth functional unit associated with the occurrence of a value of the at least one current parameter in a second pre-defined range of the value of the at least one current parameter, different from the first pre-defined range.

[0055] In one advantageous set of embodiments, the set of different functional units may include all five the above-outlined first, second, third, fourth and fifth functional units.

[0056] In one set of embodiments, the first functional unit may comprise a reciprocating-type precision hair trimmer, the second functional unit may comprise a reciprocating -type nose trimmer, the third functional unit may be a reciprocating-type beard styler, the fourth functional unit may be a rotarytype shaving unit, and / or the fifth functional unit may be a rotary-type facial cleaning brush.

[0057] Another aspect of the invention is a computer-implemented method for identifying a selected one of a set of different functional units attached to a connection interface of a main body of a personal care device, the connection interface being adapted to enable connection of any selected one of the set of different functional units to the main body so as to enable driving of a movable functional component of the selected one of the set of different functional units by a motor included in the main body. The method comprises: measuring, by means of a current sensor, at least one current parameter relating to an electric current in the motor when driving at least one of the set of different functional units when connected to the main body; measuring, by means of a vibration sensor, at least one vibration parameter relating to a vibration of the main body during driving of at least one of the set of different functional units when connected to the main body; measuring, by means of a magnetic field sensor, at least one magnetic field parameter relating to a magnetic field at a fixed location relative to the main body when at least one of the set of different functional units is connected to the main body; receiving, by 2024PF00148

[0058] 9 means of a functional unit detection logic of a controller, a set of inputs; and generating, by means of the functional unit detection logic, an output signal associated with the selected one of the set of different functional units which is connected to the connection interface using the set of inputs; wherein the set of inputs includes a value of the magnetic field parameter measured by the magnetic field sensor, a value of the at least one current parameter measured by the current sensor, and a value of the at least one vibration parameter measured by the vibration sensor.

[0059] Another aspect of the invention is a computer program product comprising computer program code configured, when run on a computer, to cause the computer to perform a method in accordance with any embodiment outlined in this disclosure or in accordance with any claim.

[0060] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0061] BRIEF DESCRIPTION OF THE DRAWINGS

[0062] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0063] Fig. 1 is a schematic block diagram illustrating components of an example personal care system in accordance with one or more embodiments of the invention;

[0064] Fig. 2 is a schematic block diagram illustrating components of a further example personal care system in accordance with one or more embodiments of the invention;

[0065] Fig. 3 schematically illustrates the structure of an example functional unit detection logic utilized by a controller of a personal care device drive unit in accordance with one or more embodiments of the invention;

[0066] Fig. 4 outlines in further detail the structure of an example functional unit detection logic in accordance with one or more embodiments of the invention;

[0067] Fig. 5 outlines in further detail the structure of an example functional unit detection logic in accordance with one or more embodiments of the invention;

[0068] Fig. 6 shows a representation of an example personal care device main body and a set of functional units attachable to the main body;

[0069] Fig. 7 and Fig. 8 illustrate components of an example personal care system in accordance with one or more embodiments of the invention, wherein the personal device drive unit includes a pressure sensing subsystem;

[0070] Fig. 9 shows a cross-section through an interior of an example implementation of a personal care device drive unit in accordance with one or more embodiments of the invention;

[0071] Fig. 10 schematically illustrates a pressure sensing subsystem suitable for use in a personal care device drive unit of one or more embodiments of the invention; 2024PF00148

[0072] 10

[0073] Fig. 11 schematically illustrates the magnetic arrangement in three possible scenarios in accordance one or more embodiments of the invention;

[0074] Fig. 12 shows an example set of value ranges of the magnetic field parameter measured by the magnetic field sensor, wherein each of the value ranges corresponds to a different possible scenario in accordance with one or more embodiments; and

[0075] Fig. 13 outlines the structure of an example functional unit detection logic in accordance with one or more embodiments of the invention.

[0076] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0077] The invention will be described with reference to the Figures.

[0078] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0079] The invention provides a personal care device drive unit, personal care system and a method for detecting which of a set of different functional units is attached to the personal care device drive unit using a combination of: at least one parameter related to an electric current in a motor of the personal care device drive unit, at least one parameter relating to a vibration of a main body of the personal care device drive unit, and at least one parameter of a magnetic field measured by a magnetic field sensor at a fixed location in the main body of the personal care device drive unit. At least one of the set of different functional units includes a functional unit having an integrated magnetic field modifier which modifies a magnetic field detectable at the fixed location in the main body into a pre-determined value.

[0080] In one example set of embodiments, the magnetic field sensor is used by a pressure sensing subsystem for a pressure sensing function, in addition to being used by a functional unit detection logic for differentially detecting which of the set of different functional units is connected to the personal care device drive unit.

[0081] Fig. 1 shows an example implementation of a personal care device drive unit 13 in accordance with one or more embodiments of the invention. The personal care device drive unit 13 is shown in the context of a personal care device 12 which comprises the personal care device drive unit 13 and a personal care system 10 which comprises the personal care device drive unit 13 and a set 20 of different functional units 22_1,. . . ,22_N, which are each selectively attachable to the personal care device drive unit. The personal care device drive unit 13, the personal care device 12 and the personal care system 10 are all aspects of the invention. 2024PF00148

[0082] 11

[0083] The personal care device drive unit 13 comprises a main body 14. The personal care device drive unit further comprises a motor 18 arranged in the main body. The personal care device drive unit 13 comprises a connection interface 16 arranged on the main body 14. The connection interface 16 is adapted to enable connection of any selected one of a set 20 of different functional units 22_n to the main body 14. An exemplary set 20 of functional units is schematically represented in Fig. 1. The exemplary set 20 of functional units includes a first functional unit 22_1, a second functional unit 22_2, a third functional unit 22_3, a fourth functional unit 22_4 and a fifth functional unit 22_5. Although the set 20 of different functional units in the depicted example comprises five functional units, the set 20 may include a different number of functional units, either a greater number or a smaller number. The functional units may be referred to generically in this disclosure by the reference numeral 22_n.

[0084] Each one 22_n of the set 20 of different functional units includes a moveable functional component. The moveable functional component is for example for enabling a functional action of the functional unit 22_n. The functional action is for example an action contributing to a personal care function. Each of the different functional units may be for use in performing a different personal care function.

[0085] The connection interface 16 is adapted to enable connection of any selected one of the set 20 of different functional units 22_n to the main body 14 so as to enable driving of the movable functional component of the selected one of the set 20 of different functional units by the motor 18 accommodated in the main body 14. The connection interface 16 is for example a mechanical connection interface. The connection interface may optionally additionally be an electrical connection interface. An example of a suitable implementation of a mechanical connection interface is disclosed by EP2086729B2 in the name of the applicant.

[0086] The personal care device drive unit 13, when connected to one of the set 20 of functional units 22_n, forms a personal care device 12. The personal care device drive unit 13, in combination with the set 20 of different functional units 22_n, forms a personal care system 10. The set 20 of different functional units 22_n may be included as a part of the provided system 10. Alternatively, they may be separate to the system, and wherein the personal care device 12 is operable to connect with them.

[0087] The personal care device drive unit 13 comprises a current sensor 32 arranged for measuring at least one current parameter relating to an electric current in the motor 18 when driving at least one of the set 20 of different functional units 22_n when connected to the main body 14. The current sensor 32 may be configured to generate an output signal 33 indicative, directly or indirectly, of a value, I t, of the at least one current parameter. The current sensor 32 may be arranged in the main body 14 of the personal care device drive unit 13.

[0088] By way of non-limiting example, the at least one current parameter may include an amplitude of the current in the motor 18, a peak amplitude of the current in the motor over a defined time window, an instantaneous current of the motor, an / or a frequency of the current in the motor. The output signal 33 of the current sensor 32 may be a continuous signal representative of a real-time current in the 2024PF00148

[0089] 12 motor. Alternatively, the output signal of the current sensor may be a data signal carrying data indicative of a value of the at least one current parameter which has been extracted or computed from a measure of the real-time current in the motor.

[0090] The personal care device drive unit 13 further comprises a vibration sensor 36 arranged in the main body 14 for measuring at least one vibration parameter relating to a vibration of the main body 14 during driving of at least one of the set 20 of different functional units 22_n when connected to the main body 14. The vibration sensor 36 may be configured to generate an output signal 37 indicative, directly or indirectly, of a value, V_t, of the at least one vibration parameter.

[0091] By way of example, the vibration sensor 36 may comprise one or more accelerometers. By way of example, the vibration sensor 36 may comprise an inertial measurement unit.

[0092] By way of non-limiting example, the at least one vibration parameter may include a vibration amplitude, a peak vibration amplitude over a defined time window, and / or a vibration frequency. The output signal 37 of the vibration sensor 36 may be a continuous signal representative of vibratory motion of the device, e.g. an output signal of one or more accelerometers. Additionally, or alternatively, the output signal 37 of the vibration sensor 36 may be a data signal carrying data indicative of a value of the at least one vibration parameter which has been extracted or computed from a continuous signal representative of a real-time vibratory motion of the main body 14.

[0093] The personal care device drive unit 13 further comprises a magnetic field sensor 34. By way of example, the magnetic field sensor 34 may be a Hall sensor. The magnetic field sensor is mounted in a fixed position relative to the main body 14. The magnetic field sensor is for measuring at least one magnetic field parameter relating to a magnetic field at a fixed location relative to the main body 14 (at least) when at least one of the set 20 of different functional units 22_n is connected to the main body 14. In the example of Fig. 1, the magnetic field sensor 34 is mounted at a fixed position in the main body and is sensitive to a magnetic field at the location of the fixed position, i.e. in the vicinity of the magnetic field sensor. If external elements modify characteristics of the detectable magnetic field at the location of the magnetic field sensor 34, this is detectable by the magnetic field sensor. The magnetic field sensor 34 may be configured to generate an output signal 35 indicative, directly or indirectly, of a value, M t, of the at least one magnetic field parameter.

[0094] By way of example, the at least one magnetic field parameter may include a polarity of the magnetic field, and / or a magnetic field strength of the magnetic field. A value of the magnetic field strength of the magnetic field may include a magnitude of the magnetic field strength and a polarity of the magnetic field.

[0095] The personal care device drive unit 13 further comprises a controller 44. The controller comprises a functional unit detection logic 46. The functional unit detection logic 46 is configured to generate an output signal 47 associated with the selected one of the set of different functional units 22_n which is currently connected to the connection interface 16. 2024PF00148

[0096] 13

[0097] The functional unit detection logic 46 is configured to generate the output signal 47 associated with the selected one of the set 20 of different functional units 22_n in dependence upon a value, M_t, of the magnetic field parameter measured by the magnetic field sensor 34, a value, I t, of the at least one current parameter measured by the current sensor 32, and a value, V_t, of the at least one vibration parameter measured by the vibration sensor 36.

[0098] More particularly, the functional unit detection logic 46 may be configured to receive a set of inputs, and generate, using the set of inputs, the output signal 47 associated with the selected one of the set of different functional units 22_n which is connected to the connection interface 16, wherein the set of inputs include the value, M t, of the magnetic field parameter measured by the magnetic field sensor 34, the value, I t, of the at least one current parameter measured by the current sensor 32, and the value, V_t, of the at least one vibration parameter measured by the vibration sensor 36.

[0099] With regards to the functional unit detection logic 46, this may in some embodiments comprise or consist of a decision tree logic. A decision tree is a structured model used for making decisions. The decision tree comprises a plurality of decision nodes, at each of which rule(s), conditions or criteria are applied to generate a decision output based on input information. For the present invention, the generating of the output signal 47 in dependence upon the value, M t, of the magnetic field parameter measured by the magnetic field sensor 34, the value, I t, of the at least one current parameter measured by the current sensor 32, and the value, V_t, of the at least one vibration parameter measured by the vibration sensor 36 may mean that each respective one of said three values forms an input respectively to at least one decision node of a set of decision nodes comprised by a decision tree which is comprised by or which forms the functional unit detection logic 46. Implementation details with regard to the functional unit detection logic 46 will be described in greater detail later in this disclosure.

[0100] In some embodiments, the system 10 may comprise or may be associated with a mobile computing device (not shown). The mobile computing device may for example be a smartphone. The mobile computing device may include a software application installed thereon, the software application for providing a user interface for the personal care system 10. For example, the software application may provide feedback to the user with regards to previous usage of the personal care device 12. In some embodiments, the software application may permit a user to configure one or more settings of the personal care device.

[0101] With regards to the set 20 of different functional units 22_n, it will be appreciated that the principles of the invention are applicable to any possible set of functional units. All that is required is a personal care device 12 which is configurable to be used with a plurality of different functional units, wherein the system permits the user to switch the functional unit by mechanically detaching one and mechanically attaching another.

[0102] With regards to the magnetic field sensor 34, this may be used for the purpose of detecting an influence on said parameter of a magnetic field at said fixed location by a respective magnetic field modifier carried by the selected one of the set 20 of different functional units 22_n. The 2024PF00148

[0103] 14 magnetic field modifier unit may have a magnetic signature which is detectable at the magnetic field sensor 34 when the functional unit 22_n which carries the magnetic field modifier unit is connected to the connection interface 16.

[0104] Fig. 2 schematically illustrates an example implementation of a personal care system 10 according to one or more embodiments of the invention in which at least one of the set 20 of functional units 22_n comprises a magnetic field modifier 52. The personal care system 10 comprises a personal care device drive unit 13 and a set 20 of different functional units 22_n, each being releasably connectable to the connection interface 16 of the main body 14 of the personal care device drive unit 13. At least one of the set 20 of different functional units 22_n includes a magnetic field modifier 52. When said at least one of the set 20 of different functional units 22_n is connected to the main body 14, the magnetic field modifier 52 modifies a value, M t, of the magnetic field parameter measured by the magnetic field sensor 34 into a predetermined value. In other words, the magnetic field modifier 52 creates a pre-determined modification or modulation to the magnetic field detectable at the magnetic field sensor 34. The modification of the value of the magnetic field parameter measured by the magnetic field sensor 34 may be understood as a magnetic signature or magnetic fingerprint of the magnetic field modifier 52, and therefore of the relevant functional unit 22_n which carries the magnetic field modifier 52.

[0105] The magnetic field modifier 52 may be a magnetic field source. For example, the magnetic field modifier may be a permanent magnet. However, other implementations are also possible. By way of one non-limiting example, it would be possible to include a magnetic field source in the personal care device drive unit 13 main body 14 and wherein the magnetic field modifier is a metallic body for modifying the magnetic field detectable at the location of the magnetic field sensor 34 by a predetermined amount by interacting with the magnetic field emitted by the magnetic field source of the personal care device drive unit 13 main body 14.

[0106] The set 20 of functional units 22_n preferably includes at least two functional units 22_n which include respective magnetic field modifiers, each configured to modify the magnetic field at the location of the magnetic field sensor 34 by a different amount or in a different way. In other words, the respective magnetic field modifiers have different magnetic signatures or magnetic fingerprints.

[0107] Fig. 2 shows one example implementation in which the set 20 of functional units includes at least a first functional unit 22_1 having a first magnetic field modifier 52a and a second functional unit 22_2 having a second magnetic field modifier 52b, wherein the second magnetic field modifier effects a different modification of the magnetic field measurable at the magnetic field sensor 34 when the second functional unit is connected to the drive unit 13 compared to the modification of the magnetic field measurable at the magnetic field sensor 34 when the first functional unit is connected to the drive unit 13. For example, the first magnetic field modifier 52a may be configured to modify the value, M t, of the magnetic field parameter measured by the magnetic field sensor 34 into a first predetermined value, and the second magnetic field modifier 52b may be configured to modify the value, M t, of the magnetic field 2024PF00148

[0108] 15 parameter measured by the magnetic field sensor 34 into a second predetermined value which is different from the first predetermined value.

[0109] The first magnetic field modifier 52a may comprise a first magnetic field source, for example a first permanent magnet. The second magnetic field modifier 52b may comprise a second magnetic field source, for example a second permanent magnet.

[0110] By way of one example implementation, the first magnetic field modifier 52a may be a magnetic field source having a first magnetic field polarity measurable by the magnetic field sensor 34 when the first functional unit 22_1 carrying the first magnetic field modifier 52a is connected to the connection interface 16. The second magnetic field modifier 52b may be a second magnetic field source having a second magnetic field polarity, opposite to the first magnetic field polarity measurable by the magnetic field sensor 34 when the second functional unit 22_2 carrying the second magnetic field modifier 52b is connected to the connection interface 16.

[0111] Fig. 3 schematically outlines the basic decision architecture of an example functional unit detection logic 46 in accordance with one or more embodiments of the invention.

[0112] The functional unit detection logic 46 receives three inputs. A first input to the functional unit detection logic 46 is an output signal 35 from the magnetic field sensor 34 indicative of a value, M t, of the magnetic field parameter measured by the magnetic field sensor 34. A second input to the functional unit detection logic 46 is an output signal 33 from the current sensor 32 indicative of a value, I t, of at least one current parameter of the electric current in the motor 18. A third input to the functional unit detection logic 46 is an output signal 37 from the vibration sensor 36 indicative of a value, V_t, of the vibration parameter of the vibration of the main body 14. The functional unit detection logic is configured to differentially identify the selected one of the set of different functional units which is connected to the connection interface using the first, second and third inputs, i.e., to generate the output signal 47 associated with the selected one of the set of different functional units using the first, second and third inputs.

[0113] With reference to Fig. 3, in some embodiments, the functional unit detection logic 46 includes at least a first detection pathway 72 in which the output signal 47 is generated 64 in dependence upon said first input, indicative of a value, M t, of the at least one magnetic field parameter measured by the magnetic field sensor 34. The functional unit detection logic 46 may further comprise at least a second detection pathway 74 in which the output signal 47 is generated 64 in dependence upon the second input indicative of a value of the at least one current parameter, I t, measured by the current sensor 32 and / or the third input indicative of a value of the at least one vibration parameter, V_t, measured by the vibration sensor 36.

[0114] The functional unit detection logic 46 may comprise a decision tree, wherein the first 72 and second 74 detection pathways are respective branches of the decision tree. The decision tree may comprise a plurality of decision nodes, which include at least a first decision node 63, and wherein the first 72 and second 74 detection pathways are decision tree branches which lead from the first decision 2024PF00148

[0115] 16 node 63. In other words, the first 72 and second 74 pathways may be (alternative) branches of a decision tree, leading from the first decision node 63, wherein the decision to execute the first pathway 72 or instead the second pathway 74 may be made based on evaluation of a pre-defined condition or criterion 62 which is defined by the first decision node 63. The pre-defined condition or criterion 62 might in some embodiments depend upon a value of one or more of: the at least one magnetic field parameter, the at least one current parameter, and the at least one vibration parameter. In other words, an input to the first decision node 63 may include a value of at least one of: the at least one magnetic field parameter, the at least one current parameter, and the at least one vibration parameter.

[0116] An example of this is illustrated in Fig. 4.

[0117] With reference to Fig. 4, in some embodiments, the functional unit detection logic 46 may be configured so as to selectively follow the first detection pathway 72 or the second detection pathway 74 based on evaluation of a pre-defined condition or criterion 62, wherein the pre-defined condition or criterion 62 depends upon: the measured value, M t, of the at least one magnetic field parameter, the measured value, I t, of the at least one current parameter, and / or the measured value, V_t, of the at least one vibration parameter.

[0118] Here, the controller 44 samples a value, M t, of the at least one magnetic field parameter using the magnetic field sensor 34, a value, I t, of the at least one current parameter using the current sensor 32 and / or a value, V_t, of the at least one vibration parameter using the vibration sensor 36 and, dependent upon the value(s), selects 62 to differentially identify the connected functional unit using the magnetic field parameter alone or by using the current and / or vibration parameters.

[0119] With reference to Fig. 4, in some embodiments, the controller 44 may comprise a memory 92 storing a plurality of value ranges. The functional unit detection logic 46 may be configured to selectively follow the first detection pathway 72 or the second detection pathway 74 in dependence upon which value range of said plurality of value ranges the measured value, M t, of the magnetic field parameter, the measured value, I t, of the at least one current parameter and / or the measured value, V_t, of the at least one vibration parameter falls into. For example, with reference to Fig. 4, the rule followed by the condition or criterion 62 of the first decision node 63 may be defined by the plurality of value ranges stored in the memory 92.

[0120] It will be understood that, if the selected one of the set 20 of different functional units 22_n which is attached to the personal care device drive unit 13 comprises a magnetic field modifier, for example having a detectable magnetic signature, then the functional unit detection logic can differentially identify the connection of this respective functional unit using a reading of the value, M t, of the magnetic field parameter measured by the magnetic field sensor 34. On the other hand, if the selected one of the set 20 of different functional units 22_n connected to the personal care device drive unit 13 does not include a magnetic field modifier 52, for example having a detectable magnetic signature, then the functional unit detection logic can use the current parameter, I t, and the vibration parameter, V_t, to differentially detect the functional unit. 2024PF00148

[0121] 17

[0122] With regards to the use of a value, V_t, of the vibration parameter and / or a value, I t, of the current parameter to detect the selected one of the set 20 of functional units 22_n which is connected to the personal care device drive unit 13, a suitable implementation of this is described in detail in document EP3855976B1 in the name of the applicant. In this document, different functional units are differentially detected based on an amplitude of vibration of the personal care device main body induced by operation of the functional unit, and / or by a current drawn by the motor when driving the functional unit.

[0123] Thus, in some embodiments, the set 20 of different functional units comprises at least one functional unit 22_n which is associated with the occurrence in the main body 14, when being driven by the motor 18, of a maximum vibration amplitude above a predefined threshold value in a predefined range of vibration frequencies. This functional unit is thus differentiable from the other two based on a value of the vibration parameter, V_t. The set 20 of different functional units 22_n may comprise first and second further functional units, associated with the occurrence of a value, I t, of the at least one current parameter in, respectively, mutually different first and second predefined ranges of the value of the at least one current parameter. Thus, these functional units are differentiable from one another based on a value, I t, of the current parameter.

[0124] It will be recognized that different functional units 22_n of the set 20 of functional units may overlap with respect to associated values of the vibration parameter, V_t, the current parameter, I t, and the magnetic field parameter, M_t which may be measurable while the respective units are being operated. By applying a detection logic in which these different parameters are sequentially evaluated against pre-defined criteria in a decision tree logic structure, it is possible to sequentially narrow down determination of which functional unit is connected.

[0125] Fig. 5 illustrates a particular implementation consistent with the set of embodiments represented in Fig. 3 and Fig. 4.

[0126] In the example implementation shown in Fig. 5, the first decision node 63 defines a predefined condition or criterion 62 which depends upon a value, M t, of the magnetic field parameter in an output signal 35 from the magnetic field sensor 34. The first decision node receives, as an input, a value, M t, of the magnetic field parameter measured by the magnetic field sensor 34. The controller 44 comprises a memory 92 which stores a set of value ranges of the magnetic field parameter. Evaluating the condition or criterion 62 defined by the first decision node 63 comprises determining which of the set of value ranges the measured value, M t, of the magnetic field parameter falls into. A first detection pathway 72 and second detection pathway 74 lead from the first decision node 63 as alternative branches of the decision tree structure. Dependent upon the outcome of evaluating the condition or criterion 62, the functional unit detection logic 46 selectively follows the first detection pathway 72 (first decision tree branch) or the second detection pathway 74 (second decision tree branch).

[0127] Along the first detection pathway 32 is a further decision node, which may be referred to as a second decision node 66. The second decision node 66 defines a condition or criterion which depends 2024PF00148

[0128] 18 upon a value, M t, of the magnetic field parameter. The second decision node 66 receives, as an input, a value, M t, of the magnetic field parameter from the magnetic field sensor 34. Dependent upon the result of the evaluation of the condition defined by the second decision node 66, the functional unit detection logic 46 follows a first decision outcome or a second decision outcome. In the first decision outcome, the functional unit detection logic generates 64 an output signal 47 associated with a first functional unit 22_1 of the set 20 of different functional units. In the second decision outcome, the functional unit detection logic generates 64 an output signal 47 associated with a second functional unit 22_2 of the set 20 of different functional units.

[0129] Along the second detection pathway 74, the functional unit detection logic 46 next evaluates a condition or criterion defined by a third decision node 68. The third decision node evaluates a condition or criterion which depends upon a value, V_t, of the vibration parameter generated by the vibration sensor 36. The third decision node receives, as an input, a value, V_t, of the vibration parameter from the vibration sensor 36. Dependent upon the result of the evaluation of the condition defined by the third decision node 68, the functional unit detection logic follows a first decision outcome or a second decision outcome. In the first decision outcome, the functional unit detection logic 46 generates 64 an output signal 47 associated with a third functional unit 22_3 of the set 20 of different functional units. In the second decision outcome, the functional unit detection logic 46 follows a further decision tree branch which leads to a fourth decision node 69. The functional unit detection logic 46 evaluates a condition or criterion defined by a fourth decision node 69. The fourth decision node evaluates a condition or criterion which depends upon a value, I t, of the current parameter generated by the current sensor 32. The fourth decision node 69 receives, as an input, a value, I t, of the current parameter from the current sensor 32. Dependent upon the result of the evaluation of the condition defined by the fourth decision node 69, the functional unit detection logic 46 follows a first decision outcome or a second decision outcome. In the first decision outcome, the functional unit detection logic 46 generates 64 an output signal 47 associated with a fourth functional unit 22_4 of the set 20 of different functional units. In the second decision outcome, the functional unit detection logic generates 64 an output signal 47 associated with a fifth functional unit 22_5 of the set 20 of different functional units.

[0130] It will be recognized that, in the example of Fig. 5, the functional unit detection logic 46 comprises a decision tree, the decision tree comprises a set of decision nodes 63, 66, 68, 69, and wherein each respective one of: a value, M t, of the magnetic field parameter measured by the magnetic field sensor 34, a value, I t, of the at least one current parameter measured by the current sensor 32, and a value, V_t, of the at least one vibration parameter measured by the vibration sensor 36, 2024PF00148

[0131] 19 forms an input respectively to at least one decision node 63, 66, 68, 69 of the set of decision nodes comprised by the decision tree.

[0132] The first decision outcome of the second decision node 66 may correspond to the value, M t, of the magnetic field parameter falling within a first range of values, and the second decision outcome of the second decision node 66 may correspond to the value, M t, of the magnetic field parameter falling within a second range of values. Optionally, the first range of values may contain values of a first polarity, and the second range of values may contain values of a second opposite polarity.

[0133] The first decision outcome of the third decision node 68 may correspond to the value, V_t, of the vibration parameter falling within a first range of values, and the second decision outcome of the third decision node 68 may correspond to the value, V_t, of the vibration parameter falling within a second range of values, wherein the first range of values is higher than the second range of values, and wherein the first and second ranges of values are non-overlapping. For brevity, the first decision outcome is labelled as ‘high’ vibration in Fig. 5, and the second decision outcome is labelled as ‘low’ vibration in Fig. 5.

[0134] The first decision outcome of the fourth decision node 69 may correspond to the value, I t, of the current parameter falling within a first range of values, and the second decision outcome of the fourth decision node 69 may correspond to the value, I t, of the vibration parameter falling within a second range of values, wherein the first range of values is higher than the second range of values, and wherein the first and second ranges of values are non-overlapping. For brevity, the first decision outcome is labelled as ‘high’ current in Fig. 5, and the second decision outcome is labelled as ‘low’ current in Fig. 5.

[0135] Further implementation details with respect to the decision logic structure will be discussed later in this disclosure.

[0136] Fig. 6 shows a representation of one example personal care device drive unit 13 and pictorial representations of one example set of functional units 22_n. The personal care device drive unit 13 main body 14 is shown. The main body 14 has a main axis of extension 15. The representation of Fig. 5 shows an exterior view of the main body 14. The connection interface 16 for connecting with the functional units is further shown. Also shown is an optional display 17 for displaying functional information to a user.

[0137] The example set of functional units represented in Fig. 6 includes a precision trimmer unit 22_1, a nose trimmer unit 22_2, a beard styler unit 22_3, shaving unit 22_4, and facial cleansing brush unit 22_5. Each of the functional units 22_n is attachable to the main body 14 of the of the personal care device 12 by connection with the connection interface 16. Each of the functional units includes a moveable functional component.

[0138] In some embodiments, each of the precision trimmer 22_1, the nose trimmer 22_2 and the beard styler 22_3 may comprise a respective moveable functional component which exhibits reciprocating-type movement. In some embodiments, each of the shaving unit 22_4 and facial cleansing 2024PF00148

[0139] 20 brush unit 22_5 may comprise a respective moveable functional component which exhibits rotary-type movement.

[0140] In some embodiments, the set 20 of different functional units 22_n may include a selection of any two or more of the above listed set of functional units. In a preferred implementation of the system, the set of different functional units includes all five of the above listed set of functional units.

[0141] As will now be discussed, in some embodiments, the magnetic field sensor 34 performs a dual role of sensing a magnetic signature of a magnetic field modifier in at least one of the set 20 of different functional units 22_n and of sensing displacement of a magnetic element as part of a pressure sensing subsystem.

[0142] Accordingly, with reference to Fig. 7, in some embodiments, the personal care system 10 comprises a pressure sensing subsystem 100. With further reference to Fig. 7, the controller 44 may further include a pressure detection logic 84 which is configured to generate an additional output signal 86 in dependence upon a value, M t, of the magnetic field parameter measured by the magnetic field sensor 34. The additional output signal 86 is associated with an external pressure 82 exerted on (at least one location of) an operational face 88 of at least one of the set 20 of different functional units 22_n when said at least one of the set of different functional units is connected to the main body 14. The pressure sensing subsystem 100 includes a further magnetic field source 102 mounted to the main body 14. The pressure sensing subsystem 100 further includes a displacement system 104 configured to generate a displacement of the further magnetic field source 102 relative to the magnetic field sensor 34 such that a distance between the further magnetic field source 102 of the pressure sensing subsystem 100 and the magnetic field sensor 34 is dependent on said external pressure 82 according to a predefined relation.

[0143] Consequently, a magnetic field strength measured by the magnetic field sensor 34 is also dependent on said external pressure 82 exerted on the operational face 88 of the functional unit 22_n according to a predefined relation.

[0144] The functional unit 22_n may include a pressure coupling mechanism which couples pressure applied to at least one location on the operational face 88 of the at least one functional unit 22_n to the displacement system 104. In other words, the pressure sensing subsystem 100 is configured such that a distance between the further magnetic field source 102 of the pressure sensing subsystem 100 and the magnetic field sensor 34 varies as a function of the external pressure 82 applied on the operational face 88 of at least one functional unit 22_n when the at least one functional unit is connected to the main body 14 of the personal care device drive unit 13. For example, the distance decreases as a function of increasing applied pressure 82 on the operational face 88 of the at least one functional unit 22_n. The pressure detection logic 84 is configured to determine a measurement of the external pressure 82 applied on the functional unit 22_n as a function of the value, M t, of the at least one magnetic field parameter output from the magnetic field sensor 34.

[0145] In some embodiments, the displacement system 104 of the pressure sensing subsystem 100 comprises an elastic suspension subsystem configured to elastically suspend the further magnetic 2024PF00148

[0146] 21 field source 102 of the pressure sensing subsystem 100 relative to a main frame of the main body 14 to which the magnetic field sensor 34 is mounted in said fixed position relative to the main body 14. The elastic suspension system may be configured to generate, when the at least one functional unit 22_n is coupled to the main body 14 and when an external force 82 is exerted on at least a portion of an operational face 88 of the at least one functional unit 22_n, a displacement of the further magnetic field source 102 of the pressure sensing subsystem 100 towards the magnetic field sensor 34. The displacement may for example be in a direction along a z-dimension, transverse to the operational face 88 of the functional unit 22_n, and against a biasing force of the elastic suspension system. For example, with reference to Fig. 6, it may be in a direction parallel to the main axis 15 of extension of the main body 14. The pressure detection logic 84 of the controller 44 may be configured for generating said additional output signal 86 in dependence upon a measured value of the at least one magnetic field parameter, e.g. a measured magnetic field strength, indicating a distance of the further magnetic field source 102 of the pressure sensing subsystem 100 to the magnetic field sensor 34 in a direction parallel to the z-direction and, therewith, a value of the external force 82.

[0147] A suitable pressure sensing subsystem 100 in accordance with the example shown in Fig. 7 and described above is described in detail in EP3852983B1 in the name of the applicant.

[0148] Fig. 8 schematically illustrates how the magnetic field sensor 34 can be used for the purpose of pressure sensing and for the secondary purpose of functional unit detection depending upon which of the set 20 of different functional units 22_n is connected to the connection interface 16 of the personal care device drive unit 13. Fig. 8 shows the embodiment of Fig. 7 when a functional unit 22_n is attached which comprises a magnetic field modifier 52 integrated therein. In this case, the output 35 of the magnetic field sensor 34 is used by the functional unit detection logic 46 for use in generating the output signal 47 associated with the selected one of the set of different functional units which is connected to the personal care device drive unit 13. When a functional unit 22_n is attached which includes a pressure coupling mechanism for coupling pressure from at least one location on the operational face of the functional unit 22_n to the displacement system 104, the output of the magnetic field sensor 34 may be used by the pressure detection logic 84 to generate the additional output signal 86 associated with the external pressure exerted on the functional unit 22_n.

[0149] Alternatively, as will be the case when using the pressure sensing subsystem as described in detail in EP3852983B1 mentioned here before, the displacement system 104 may be active for any selected one of the set of different functional units when coupled to the connection interface 16. This may be the case when, as in the example of EP3852983B1, the connection interface 16 is connected to the main body 14 by means of the elastic suspension subsystem of the displacement system 104 of the pressure sensing subsystem 100, with the further magnetic field source 102 being mounted in a fixed position on the connection interface 104. In this case, the pressure detection logic 84 may generate the additional output signal 86 for each selected one of the set of different functional units when connected to the connection interface 104. Alternatively, the pressure detection logic 84 may receive the output 47 of 2024PF00148

[0150] 22 the functional unit detection logic 46 and may generate, in dependence on the output 47 received from the functional unit detection logic 46, the additional output signal 86 only for one or more specific functional units of the set of different functional units when connected to the connection interface 104.

[0151] In some embodiments, the at least one functional unit 22_n which comprises the pressurecoupling mechanism for coupling pressure from at least one location on the operational face 88 of the functional unit 22_n to the displacement system 104 is a shaving unit. The shaving unit may comprise at least two hair-cutting units exposed on the operational face 88 of the shaving unit. Each hair-cutting unit may be mounted to a base member of the shaving unit and may comprise an external cutting member and an internal cutting member which is moveable relative to the external cutting member. The base member may comprise a coupling member which is releasably couplable to the connection interface 16 of the main body 14. An example pressure sensing subsystem suitable for use in detecting pressure applied on the cutting units of a shaving unit is detailed in EP3852983B1 in the name of the applicant.

[0152] Fig. 9 shows a cross-section through an example implementation of the personal care device drive unit 13 in accordance with one or more embodiments. In the illustrated view, the personal care device drive unit 13 has a functional unit 22_n attached to the connection interface 16 of the main body 14, wherein the functional unit in this example is a nose trimmer. The functional unit comprises a magnetic field modifier 52. Illustrated is the position of the motor 18, the vibration sensor 36 and the magnetic field sensor 34. Also shown is the position of the further magnetic field source 102 of the pressure sensing subsystem 100 (identified in Fig. 7 and Fig. 8).

[0153] In a personal care device 12 in accordance with the embodiments of Fig. 7, Fig. 8, and / or Fig. 9, when a functional unit 22_n is connected to the connection interface 16 which comprises a magnetic field modifier 52 in the form of a magnetic source, the magnetic field sensor 34 will be exposed to the magnetic fields emitted by both the magnetic field source 52 in the functional unit 22_n and the further magnetic field source 102 of the pressure sensing subsystem 100. The pressure detection logic 84 may use changes in the detected magnetic field parameter as being indicative of changes in the applied external pressure 82, because the contribution of the functional unit magnetic field source 52 to the detected magnetic field parameter can be predetermined and, therefore, disregarded by the pressure detection logic 84 to determine the contribution of the further magnetic field source 102 to the detected magnetic field parameter.

[0154] In a preferred embodiment of the invention, the set 20 of different functional units 22_n includes one subset of functional units which each include a respective magnetic field modifier 52 and a further subset of functional units 22_n none of which include a magnetic field modifier 52. In a preferred embodiment, the further subset of functional units, none of which include a magnetic field modifier, includes at least one functional unit 22_n which is configured to interact with the pressure sensing subsystem for coupling pressure 82 exerted at an operational face 88 of the device. In other words, in a preferred embodiment, the pressure sensing subsystem might be operational only in scenarios in which the attached functional unit 22_n does not include any magnetic field source 52. This may simplify 2024PF00148

[0155] 23 operation of the pressure sensing subsystem since the pressure detection logic 84 would not need to detect the changes in magnetic field caused by movement of the further magnetic field source 102 of the pressure sensing subsystem over the background magnetic field emitted by the magnetic field source 52 of the functional unit 22_n. However, this is not essential since changes in the position of the further magnetic field source 102 of the pressure detection subsystem 100 would still be detectable as variations in the net magnetic field detectable at the magnetic field sensor 34, as explained here before.

[0156] In preferred embodiments, and as discussed above, the further magnetic field source 102 of the pressure sensing subsystem 100 is comprised as an integral component of the personal care device drive unit 13. Therefore, regardless of which functional unit 22_n is attached to the personal care device drive unit 13, the further magnetic field source 102 will exert an influence on the magnetic field sensed by the magnetic field sensor 34 in dependence upon the distance between the further magnetic field source 102 and the magnetic field sensor 34.

[0157] The functional unit detection logic 46 may be configured to distinguish between at least two of the set 20 of different functional units 22_n based on at least a value, M t, of the at least one magnetic field parameter generated by the magnetic field sensor 34. The functional unit detection logic 46 may be configured to differentially detect between at least two of the set 20 of different functional units 22_n based on which value ranges of a set of pre-defined value ranges the measured value, M t, of the at least one magnetic field parameter falls within. The value ranges may be defined in advance based on knowledge of the distances between the magnetic field sensor 34 and, respectively, the further magnetic field source 102 of the pressure sensing subsystem 100 and the magnetic field source 52 in the functional unit 22_n, and further based on the relative magnetic strengths of the two magnetic field sources 52, 102.

[0158] Fig. 10 schematically illustrates the magnetic arrangement of a personal care system according to one or more embodiments. In the illustrated example, the set 20 of functional units 22_n of the personal care system comprises at least one functional unit 22_n which carries a magnetic field modifier 52, wherein the magnetic field modifier 52 is a magnetic field source, e.g. a permanent magnet. The personal care device drive unit 13 of the personal care system comprises a pressure sensing subsystem 100 which comprises a further magnetic field source 102. Fig. 10 shows the personal care device drive unit 13 with the at least one functional unit 22_n attached. When the further magnetic field source 102 of the pressure sensing subsystem 100 is in a relaxed resting state, the further magnetic field source 102 is spaced from the magnetic field sensor 34 by a first separation distance, AD_1. When the at least one functional unit 22_n is connected to the personal care device drive unit 13, the magnetic field source 52 comprised by the at least one functional unit 22_n is spaced from the magnetic field sensor 34 by a second separation distance, AD_2. The second separation distance, AD_2, is greater than the first separation distance, AD_1.

[0159] Purely by way of example, in one example implementation tested by the inventors, the first separation distance, AD_1, was set at a distance of between 1 and 5 mm, preferably between 2 and 5 mm, more preferably between 2 and 3 mm. In one particular example, it was set at a value of 2.3 mm. In 2024PF00148

[0160] 24 the same example implementation, the second separation distance, AD_2, was set at a value of between 15 and 21 mm, preferably between 16 and 20 mm. In one particular example, it was set at a value of 18 mm. These values are examples and do not limit the scope of application of the invention.

[0161] Using knowledge of the first and second separation distances AD_1, AD_2, and the magnetic strengths of the two magnetic field sources 102, 52, the functional unit detection logic 46 can be programmed to distinguish between at least two different functional units of the set 20 of different functional units which might be connected to the personal care device drive unit 13 based on a strength and / or polarity of a magnetic field which is detected at the magnetic field sensor 34.

[0162] An example implementation will now be discussed with reference to Fig. 11 and Fig. 12.

[0163] With reference to Fig. 11, in some embodiments, at least a first functional unit 22_1 of the set 20 of different functional units includes a first magnetic field source 52a having a first magnetic field polarity measurable by the magnetic field sensor 34 when the first functional unit 22_1 is connected to the connection interface 16. The outline of the first functional unit 22_1 is indicated in schematic form in Fig. 11 and is not true to scale. In the illustrated example, the magnetic field polarity of the first magnetic field source 52a is a negative magnetic field polarity (-), however, this is not essential. In some embodiments, at least a second functional unit 22_2 of the set 20 of different functional units includes a second magnetic field source 52b having a second magnetic field polarity, opposite to the first magnetic field polarity and measurable by the magnetic field sensor 34 when the second functional unit 22_2 is connected to the connection interface 16. The outline of the second functional unit 22_2 is indicated in schematic form in Fig. 11 and is not true to scale. In the illustrated example, the magnetic field polarity of the second magnetic field source 22_2 is a positive magnetic field polarity (+), however, this is not essential. In some embodiments, at least a third functional unit 22_3 of the set 20 of different functional units 22_n does not comprise any magnetic field source 52. The outline of the third functional unit 22_3 is indicated in schematic form in Fig. 11 and is not true to scale.

[0164] Fig. 11 schematically illustrates the magnetic state of the system in each of three different scenarios. In scenario (a), the aforementioned first functional unit 22_1 comprising the first magnetic field source 52a is connected to the personal care device drive unit 13. In scenario (b), the aforementioned third functional unit 22_3 of the set 20 of different functional units is connected to the personal care device drive unit 13. In scenario (c), the aforementioned second functional unit 22_2 of the set 20 of different functional units is connected to the personal care device drive unit 13. In each scenario, the further magnetic field source 102 of the pressure sensing subsystem 100 and, if applicable, the relevant magnetic field source 52a, 52b of the functional unit 22_1, 22_2 is schematically shown relative to the position of the magnetic field sensor 34. In the example depicted, the further magnetic field source 102 of the pressure sensing subsystem 100 has a positive magnetic field polarity (+), but this is not essential.

[0165] With regards to the strength of the first 52a and second 52b magnetic field sources as compared with the further magnetic field source 102 of the pressure sensing subsystem 100, a general consideration is that the magnet strength of each of the first 52a and second 52b magnetic field sources 2024PF00148

[0166] 25 should be high enough so that it is detectable over the magnet strength of the further magnetic field source 102, and given the tolerances of the sensor and of the magnet manufacture. On the other hand, it is advantageous to minimize the magnet strength as far as practical, to avoid any unintended magnetic field creation towards the user.

[0167] In some embodiments, a magnitude of the strength of the (negative) magnetic field generated by the first magnetic field source 52a at the location of the magnetic field sensor 34 is greater than a magnitude of the strength of the (positive) magnetic field generated by the further magnetic field source 102 of the pressure detection subsystem 100 at the location of the magnetic field sensor 34. A magnitude of the strength of the (positive) magnetic field generated by the second magnetic field source 52b at the location of the magnetic field sensor 34 may be greater than a magnitude of the strength of the (positive) magnetic field generated by the further magnetic field source 102 of the pressure detection subsystem 100 at the location of the magnetic field sensor 34. Optionally, a magnitude of the strength of the (negative) magnetic field generated by the first magnetic field source 52a at the location of the magnetic field sensor 34 may be approximately equal to a magnitude of the strength of the (positive) magnetic field generated by the second magnetic field source 52b at the location of the magnetic field sensor 34.

[0168] Fig. 12 illustrates a set of possible ranges of the magnetic field strength detectable by the magnetic field sensor 34, spanning across both positive and negative magnetic field strengths. In this example, the at least one magnetic field parameter which the magnetic field sensor 34 is configured to detect comprises magnetic field strength and magnetic field polarity. The set of possible ranges correspond to expected ranges into which the measured value, M t, of the magnetic field strength will fall in each of a set of different scenarios.

[0169] Range A indicated in Fig. 12 corresponds to a range of magnetic field strength values into which a magnetic field strength measured by the magnetic field sensor 34 is expected to fall in scenario

[0170] (a) identified in Fig. 11. Range A corresponds to a small negative polarity magnetic field strength at the location of the magnetic field sensor 34. This can be understood from considering a superposition of the stronger negative polarity magnetic field of the first magnetic field source 52a with the weaker positive polarity magnetic field of the further magnetic field source 102 of the pressure sensing subsystem 100. The combination of these two fields is a small negative positive polarity magnetic field at the location of the magnetic field sensor 34.

[0171] Range B indicated in Fig. 12 corresponds to a range of magnetic field strength values into which a magnetic field strength measured by the magnetic field sensor 34 is expected to fall in scenario

[0172] (b) identified in Fig. 11. Range B corresponds to a small positive polarity magnetic field strength at the location of the magnetic field sensor 34. This can be understood from considering that the magnetic field strength detectable at the magnetic field sensor 34 is reflective only of the small-magnitude positive polarity magnetic field of the further magnetic field source 102 of the pressure sensing subsystem 100. This gives rise to a small positive polarity magnetic field at the location of the magnetic field sensor 34. 2024PF00148

[0173] 26

[0174] Range C indicated in Fig. 12 corresponds to a range of magnetic field strength values into which a magnetic field strength measured by the magnetic field sensor 34 is expected to fall in scenario (c) identified in Fig. 11. Range C corresponds to a relatively large positive polarity magnetic field strength at the location of the magnetic field sensor 34. This can be understood from considering a superposition of the larger-magnitude positive polarity magnetic field of the second magnetic field source 52b with the weaker positive polarity magnetic field of the further magnetic field source 102 of the pressure sensing subsystem 100. The combination of these two fields is a relatively large positive polarity magnetic field at the location of the magnetic field sensor 34.

[0175] If a magnetic field strength is measured at the magnetic field sensor 34 which is within range A, then a decision outcome of the functional unit detection logic 46 may be that the first functional unit 22_1 (comprising the first magnetic field source 52a) is connected to the personal care device drive unit 13. If a magnetic field strength is measured at the magnetic field sensor 34 which is within range C, then a decision outcome of the functional unit detection logic 46 may be that the second functional unit 22_2 (comprising the second magnetic field source 52b) is connected to the personal care device drive unit 13.

[0176] The ranges A, B and C identified above are defined assuming that the further magnetic field source 102 of the pressure-sensing subsystem 100 is in a relaxed neutral state. The relaxed neutral state is a state wherein no external pressure 82 is being applied to the operational face 88 of the functional unit 22_n which is connected to the connection interface 16. In other words, setting fixed boundaries to the ranges A, B and C relies on an assumed fixed position of the further magnetic field source 102 of the pressure detection subsystem 100. If an external pressure 82 is exerted while magnetic field measurements are being acquired for input to the functional unit detection logic 46, then the functional unit detection becomes more complex. Functional unit detection might be performed in an initial setup phase or configuration phase of operation, in advance of starting a personal care session in which a personal care function is performed. During this initial setup or configuration phase, the user may leave the functional unit 22_n in a state in which pressure is not being applied to the functional unit.

[0177] Two further possible ranges of values of the magnetic field strength, M_t, measured by the magnetic field sensor 34 can be defined, labelled as El and E2 in Fig. 12.

[0178] El corresponds to a magnetic field strength which would be measured in a variant of scenario (b) or (c), as shown in Fig. 11, in which pressure is being applied to the operational face 88 of the functional unit, thereby bringing the further magnetic field source 102 of the pressure sensing subsystem 100 closer to the magnetic field sensor 34. This results in a positive magnetic field at the location of the magnetic field sensor 34 which is larger than the upper bound of range C, which might be referred to as a very large positive polarity magnetic field. If a value of the magnetic field strength, M_t, output by the magnetic field sensor 34 falls within range El, the functional unit detection logic 46 may be configured to generate a decision output indicative of an error state, the error state corresponding to pressure being applied on the functional unit. By way of example, responsive an El error state being 2024PF00148

[0179] 27 detected, the controller 44 may be configured to control a user interface of the personal care system 10 to generate an error message for the user, communicating to the user that pressure is being applied to the functional unit.

[0180] E2 corresponds to a magnetic field strength which would be measured in a variant of scenario (a) in which the personal care device is being held upside down while the first functional unit 22_1, comprising the first magnetic field source 52a, is attached. In this scenario, the force of gravity may act to pull the magnetic field source 102 of the pressure sensing subsystem 100 away from its neutral resting position in a direction that increases a separation distance between the magnetic field sensor 34 and the (positive polarity) further magnetic field source 102. This results in a negative magnetic field at the location of the magnetic field sensor 34 which is larger in (negative) magnitude than the lower bound of range A, which might be referred to as a large negative polarity magnetic field. If a value of the magnetic field strength, M_t, output by the magnetic field sensor 34 falls within range E2, the functional unit detection logic 46 may be configured to generate a decision output indicative of an error state, the error state corresponding to the functional unit being held in a non-upright position. By way of example, responsive to an E2 error state being detected, the controller 44 may be configured to control a user interface of the personal care system 10 to generate an error message for the user, communicating to the user that the device is being held in a non-upright position.

[0181] The appropriate boundaries of the ranges A, B and C and optionally El and E2 depend upon the particular specifications of the first and second magnetic field sources 52a, 52b and the further (pressure-detection) magnetic field source 102, in addition to the specific spatial configuration of the various magnets within the personal care device drive unit 13 and the functional units 22_n. The boundaries of the ranges can readily be determined empirically for a given implementation of the personal care system. In particular, readings can be sampled from the magnetic field sensor 34 in each of scenarios (a), (b) and (c) shown in Fig. 11 outlined above and then boundaries selected for Ranges A, B and C in dependence thereon. A plurality of samples can be taken of the magnetic field sensor output for each scenario and an average taken.

[0182] By way of non-limiting illustration, in one example implementation, a further magnetic field source 102 of the pressure sensing subsystem 100 may be used which has a maximum energy product of approximately 30 to 40 MGOe (megagauss-oersteds). The further magnetic field source 102 may comprise a Neodymium magnet. In one example implementation, a neodymium magnet was used having a diameter of 3 mm and a height of 1 mm. In one example implementation, the neodymium magnet has a grade N40.

[0183] By way of non-limiting illustration, in one example implementation, each of the first magnetic field source 52a and second magnetic field source 52b may comprise a magnet having a maximum energy product of approximately 40-43 MGOe (megagauss-oersteds). Each of the first magnetic field source 52a and second magnetic field source 52b may comprise a respective neodymium magnet. In one example implementation, each respective neodymium magnet has a grade N45. Thus, in 2024PF00148

[0184] 28 this example, the first 52a and second 52b magnetic field sources of the first 22_1 and second 22_2 functional units are stronger than the further magnetic field source 102 used in the pressure sensing subsystem 100.

[0185] Fig. 11 and Fig. 12 illustrate one example set of embodiments in which the first magnetic field modifier 52a is a magnetic field source which generates a magnetic field having a first polarity when measured at the magnetic field sensor 34, and the second magnetic field modifier 52b is a magnetic field source which generates a magnetic field having a second polarity when measured at the magnetic field sensor 34. However, other example implementations are possible. For example, the first 52a and second 52b magnetic field modifiers might be implemented with first and second magnetic field sources which have a same polarity when measured at the magnetic field sensor 34 but which differ with respect to the magnetic field strength of the magnetic field which each generates and which is measurable at the magnetic field sensor 34. By way of further example, for example, the first 52a and second 52b magnetic field modifiers might be implemented with first and second magnetic field sources which have a same polarity when measured at the magnetic field sensor 34 but which differ in terms of a net direction of the magnetic field generated by the respective magnetic field source at the location of the magnetic field sensor. In this case, the magnetic field sensor may be configured to measure a magnetic field strength and a net direction of the magnetic field at the location of the magnetic field sensor 34. For example, the magnetic field sensor 34 may comprise a multi-axis hall sensor to thereby enable the magnetic field sensor to detect a magnetic field strength in each of three orthogonal vector directions. The first 52a and second 52b magnetic field modifiers may each be mounted in or on the first and second functional units respectively in such a way that they are differently oriented relative to the magnetic field sensor 34 when the first and second functional units are connected to the connection interface. This would give rise to magnetic fields having different net directions at the location of the magnetic field sensor.

[0186] Fig. 13 shows the functional unit detection logic 46 in accordance with one example set of embodiments of the invention.

[0187] Optionally, the functional unit detection logic 46 of Fig. 13 may be suitable for use with a personal care device drive unit 13 in accordance with the embodiment of Figs 7-8 and Figs. 10-12 described previously. However, the functional unit detection logic 46 of Fig. 13 is also suitable for use with personal care device drive units 13 not in accordance with the embodiment of Figs 7-8 and Figs. 10- 12 described previously. Optionally, the functional unit detection logic 46 of Fig. 13 may be suitable for use in an embodiment of the personal care device drive unit 13 which is operably coupleable with each of a set of at least five different functional units. The set of at least five different functional units may include a first functional unit 22_1 which comprises a first magnetic field source 52a having a negative magnetic polarity, for example consistent with the first functional unit comprising the first magnetic field source 52a described above with reference to Fig. 11 and Fig. 12. The set of at least five different functional units may include a second functional unit 22_2 which comprises a second magnetic field source 52b having a positive magnetic polarity, for example consistent with the second functional unit 2024PF00148

[0188] 29 comprising the second magnetic field source 52b described above with reference to Fig. 11 and Fig. 12. The set of five different functional units may further include a third functional unit 22 3, a fourth functional unit 22_4 and a fifth functional unit 22_5, none of which includes an integrated magnetic field source.

[0189] With reference to Fig. 13, in this set of embodiments, the functional unit detection logic 46 includes at least a first detection pathway 72 in which the output signal 47 is generated 64 in dependence upon a value, M t, of the at least one magnetic field parameter measured by the magnetic field sensor 34. The functional unit detection logic 46 further comprises at least a second detection pathway 74 in which the output signal 47 is generated 64 in dependence upon a value, I t, of the at least one current parameter measured by the current sensor 32 and a value of the at least one vibration parameter, V_t, measured by the vibration sensor 36.

[0190] The basic structure of the detection logic in this embodiment can be understood, in summary, as follows. If one or other of the first functional unit 22_1 or second functional unit 22_2, which each comprise an integrated magnetic field source 52 with detectable magnetic signature, is connected to the personal care device drive unit 13, then the functional unit detection logic 46 can identify which functional unit has been connected to the device using the first detection pathway 72, i.e. the first branch of the decision tree, in which detection of the functional unit may be performed based on a reading 35 of the value, M t, of the magnetic field parameter from the magnetic field sensor 34 alone. However, if one of the third 22_3, fourth 22_4 or fifth 22_5 functional units is connected to the personal care device drive unit 13, none of which comprises an integrated magnetic field source 52, then the reading of the magnetic field parameter M_t will not enable the functional unit detection logic 46 to distinguish between the three possible functional units. The functional unit detection logic 46 in this case needs to follow the second detection pathway 74, i.e. second branch of the decision tree, in which determination (differential identification) of the connected functional unit is further performed using measurements of a value, V_t, of the vibration parameter output by the vibration sensor 36, and / or of the current parameter, I t, output by the current sensor 32.

[0191] For the present embodiment, it is proposed that the third functional unit 22_3 is associated with the occurrence in the main body 14, when being driven by the motor 18, of a maximum vibration amplitude above a predefined threshold value in a predefined range of vibration frequencies. This functional unit is thus differentiable from the fourth 22 4 and fifth 22 5 functional units based on a value of the vibration parameter, V_t. It is further proposed that the fourth functional unit 22 4 and the fifth functional unit 22_5 be associated with the occurrence of a value, I t, of the at least one current parameter in, respectively, mutually different first and second predefined ranges of the value of the at least one current parameter. Thus, these functional units are differentiable from one another based on a value, I t, of the current parameter.

[0192] The detection logic pathways 72, 74 may be respective branches of a decision tree. 2024PF00148

[0193] 30

[0194] As illustrated in Fig. 13, the first 72 and second 74 pathways may be (alternative) parallel branches of a decision tree, and wherein the decision to execute the first pathway 72 or instead the second pathway 74 may be made based on evaluation of a pre-defined condition or criterion 62 which defines a first decision node 63 of the decision tree. The pre-defined condition or criterion 62 in this embodiment is a condition or criterion which depends upon a value, M t, of the at least one magnetic field parameter. In other words, the value, M t, of the at least one magnetic field parameter forms an input to the first decision node 63 of the decision tree. The functional unit detection logic 46 is thus configured so as to selectively follow the first detection pathway 72 and / or the second detection pathway 74 based on evaluation of the pre-defined condition or criterion 62 of the first decision node 63, and wherein the predefined condition or criterion 62 of the first decision node depends upon a measured value, M t, of the at least one magnetic field parameter.

[0195] In the embodiment of Fig. 13, the controller 44 comprises a memory 92 storing a plurality of value ranges for the at least one magnetic field parameter. The value ranges in the illustrated example are labelled as Range A, Range B, and Range C. The functional unit detection logic 46 may be configured to selectively follow the first detection pathway 72 and / or the second detection pathway 74 in dependence upon which value range (A, B or C) of said plurality of value ranges the measured value, M t, of the magnetic field parameter, falls into. In other words, the rule followed by the condition or criterion 62 in the first decision node 63 may be defined by the plurality of value ranges stored in the memory 92.

[0196] For the embodiment of Fig. 13, the value ranges A, B and C may correspond to the ranges A, B and C for the magnetic field strength identified in Fig. 12 and discussed above, however this is not essential. The functional unit detection logic of Fig. 13 is thus, optionally, suitable for application in a personal care system 10 in accordance with that discussed above with reference to Figs. 10-12.

[0197] As was discussed previously, Range A corresponded to a case in which the functional unit 22_n attached to the personal care device drive unit 13 comprised a first integrated magnetic field source 52a having a negative magnetic polarity, Range C corresponded to a case in which the functional unit 22_n attached to the personal care device drive unit 13 comprised a second magnetic field source 52b having a positive magnetic polarity, and Range B corresponded to a case in which the functional unit 22_n attached to the personal care device drive unit 13 comprised no integrated magnetic field source.

[0198] Accordingly, in the first decision node 63, the functional unit detection logic decides whether the measured value, M t, of the at least one magnetic field parameter, falls into any one of Range A, Range B, or Range C. The functional unit detection logic 46 follows the first detection pathway 72 (i.e. first decision tree branch) from the first decision node 63 in the event that the measured value, M t, of the at least one magnetic field parameter falls into either Range A or Range C, and follows the second detection pathway 74 (i.e. second decision tree branch) from the first decision node 63 in the event that the measured value, M t, of the at least one magnetic field parameter falls into Range B.

[0199] On the first detection pathway 72, the functional unit detection logic 46 next evaluates a condition or criterion defined by a second decision node 66. The second decision node 66 evaluates which 2024PF00148

[0200] 31 of Range A or Range C the value, M_t, of the at least one magnetic field parameter falls into. If the value, M t, of the at least one magnetic field parameter falls into range A, the functional unit detection logic 46 generates a final decision outcome in which an output signal 47 is generated 64 by the functional unit detection logic 46 which is associated with the aforementioned first functional unit 22_1. If the value, M t, of the at least one magnetic field parameter falls into range C, the functional unit detection logic 46 generates a final decision outcome in which an output signal 47 is generated 64 by the functional unit detection logic 46 which is associated with the aforementioned second functional unit 22_2.

[0201] On the second detection pathway 74 (second decision tree branch), the functional unit detection logic next evaluates a condition or criterion defined by a third decision node 68. The third decision node evaluates a condition or criterion which depends upon a value, V_t, of the vibration parameter generated by the vibration sensor 36. The controller samples a value, V_t, of the vibration parameter from the vibration sensor 36. An output signal 37 from the vibration sensor 36 encoding the sampled value, V_t, of the vibration parameter forms an input to the third decision node to evaluate the condition or criterion which depends upon the value of the vibration parameter. The condition or criterion may comprise determining whether a maximum vibration amplitude of a vibration of the main body 14 (as represented by the vibration parameter) is above a pre-defined threshold within a pre-defined range of vibration frequencies. The pre-defined threshold and the pre-defined range of vibration frequencies are defined so that a maximum vibration amplitude of the main body which is associated with use of the third functional unit falls above the pre-defined threshold within the pre-defined range of vibration frequencies.

[0202] If the maximum vibration amplitude of a vibration of the main body 14 (as represented by the vibration parameter) is above a pre-defined threshold within a pre-defined range of vibration frequencies, then the functional unit detection logic 46 generates a final decision outcome in which an output signal 47 is generated 64 by the functional unit detection logic 46 which is associated with the aforementioned third functional unit 22_3. For brevity, this is labelled as ‘high’ vibration in Fig. 13.

[0203] If the maximum vibration amplitude of a vibration of the main body 14 (as represented by the vibration parameter) is below the pre-defined threshold within the pre-defined range of vibration frequencies (labelled as ‘low’ vibration in Fig. 13) then the functional unit detection logic 46 next evaluates a condition or criterion defined by a fourth decision node 69. The fourth decision node evaluates a condition or criterion which depends upon a value, I t, of the current parameter generated by the current sensor 32. The controller samples a value, I t, of the current parameter from the current sensor 32. An output signal 33 from the current sensor 32 encoding the sampled value, I t, of the current parameter forms an input to the fourth decision node 69 to evaluate the condition or criterion which depends upon the value of the current parameter. The condition or criterion may comprise determining whether the measured value, I t, of the current parameter falls within a first predefined range of values of the current parameter or falls within a second pre-defined range values of the current parameter, wherein the first pre-defined range of values is higher than the second pre-defined range of values, and wherein the first and second ranges are non-overlapping. The first pre-defined range and the second pre-defined 2024PF00148

[0204] 32 range are defined so that operation of the fourth functional unit 22_4 is associated with occurrence of a value of the current parameter which falls within the first pre-defined range and operation of the fifth functional unit 22_5 is associated with occurrence of a value of the current parameter which falls within the second pre-defined range.

[0205] If the current of the motor 18 (as represented by the current parameter) falls within the first pre-defined range of values, then the functional unit detection logic 46 generates a final decision outcome in which an output signal 47 is generated 64 by the functional unit detection logic 46 which is associated with the aforementioned fourth functional unit 22_4. For brevity, this is labelled as ‘high’ current in Fig. 13.

[0206] If the current of the motor 18 (as represented by the current parameter) falls within the second pre-defined range of values, then the functional unit detection logic 46 generates a final decision outcome in which an output signal 47 is generated 64 by the functional unit detection logic 46 which is associated with the aforementioned fifth functional unit 22_5. For brevity, this is labelled as ‘low’ current in Fig. 13.

[0207] By way of one example implementation, the aforementioned third functional unit 22 3 comprises a functional component configured to perform a reciprocating motion, and the aforementioned fourth functional unit 22 4 and fifth functional unit 22 5 each comprise functional units configured to perform a rotating motion in a single direction. The functional unit which is driven to perform reciprocating motion has a natural frequency of vibration correlated with the frequency of reciprocation of the motion. Thus, operation of this unit is readily detectable via evaluation of a vibration parameter of the personal care device main body 13. The functional units which are driven with rotational motion in a single direction are less readily detectable based on a vibration parameter of the personal care device main body 13. Operation of these functional units is thus more readily detectable using the current parameter.

[0208] By way of one example implementation of the above-outlined embodiment, the first functional unit 22_1 may be a precision trimmer, the second functional unit 22_2 may be nose trimmer, the third functional unit 22_3 may be a beard styler, the fourth functional unit 22_4 may be a shaving unit and the fifth functional unit 22 5 may be a cleansing brush.

[0209] In some embodiments, responsive to the output signal 47 of the functional unit detection logic 46, the controller 44 may be configured to configure one or more operational parameters of the personal care device drive unit 13, for example configuring a motor speed and / or configuring settings of a user interface.

[0210] In some embodiments, responsive to the output signal 47 of the functional unit detection logic 46 indicating detection of a shaving unit 22_4 being connected to the connection interface, the controller 44 may be configured to adjust a motor speed of the motor 18. In some embodiments, the controller may be configured to control a user interface of the personal care system 10 to present to a user a set of selectable modes for operation of the shaving unit, each selectable mode being associated with a 2024PF00148

[0211] 33 different motor speed. By way of one illustrative example, the set of selectable modes may include a sensitive mode, a regular mode and an intense mode, wherein these are associated respectively with a first motor speed, a second motor speed and a third motor speed, in increasing order of speed. The user interface may permit the user to select one of the modes and the controller may be configured to adjust the motor speed in accordance with the user-selected mode.

[0212] In some embodiments, responsive to the output signal 47 of the functional unit detection logic 46 indicating detection of a facial cleaning brush unit 22_5 being connected to the connection interface, the controller 44 may be configured to adjust a motor speed of the motor 18. In some embodiments, the controller may be configured to control a user interface of the personal care system 10 to present to a user a set of selectable modes for operation of the facial cleaning brush 22_5, each selectable mode being associated with a different motor speed. By way of one illustrative example, the set of selectable modes may include a sensitive mode, and a regular mode, wherein these are associated respectively with a first motor speed, and a second (higher) motor speed. The user interface may permit the user to select one of the modes and the controller may be configured to adjust the motor speed in accordance with the user-selected mode.

[0213] Embodiments of the invention described above employ a controller. The controller may comprise one or more processors. The controller may in general comprise a single processor or a plurality of processors. It may be located in a single containing device, structure or unit, or it may be distributed between a plurality of different devices, structures or units. Reference therefore to the controller being adapted or configured to perform a particular step or task may correspond to that step or task being performed by any one or more of a plurality of processing components, either alone or in combination. The skilled person will understand how such a distributed controller can be implemented. The controller may comprise a communication module or input / output for receiving data and outputting data to further components.

[0214] The one or more processors of the processing device can be implemented in numerous ways, with software and / or hardware, to perform the various functions required. A processor typically employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform the required functions. The processor may be implemented as a combination of dedicated hardware to perform some functions and one or more programmed microprocessors and associated circuitry to perform other functions.

[0215] Examples of circuitry that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0216] In various implementations, the processor may be associated with one or more storage media such as volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM. The storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform the required functions. Various storage media may be fixed 2024PF00148

[0217] 34 within a processor or controller or may be transportable, such that the one or more programs stored thereon can be loaded into a processor.

[0218] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0219] A single processor or other unit may fulfill the functions of several items recited in the claims.

[0220] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0221] A computer program may be stored / distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to".

[0222] Any reference signs in the claims should not be construed as limiting the scope.

Claims

2024PF0014835CLAIMS:Claim 1. A personal care device drive unit (13) comprising: a main body (14); a motor (18) arranged in the main body; a connection interface (16) arranged on the main body (14) and adapted to enable connection of any selected one of a set (20) of different functional units (22_n) to the main body so as to enable driving of a movable functional component of the selected one of the set of different functional units by the motor (18); a current sensor (32) arranged for measuring at least one current parameter relating to an electric current in the motor (18) when driving at least one of the set (20) of different functional units (22_n) when connected to the main body (14); a vibration sensor (36) arranged in the main body (14) for measuring at least one vibration parameter relating to a vibration of the main body (14) during driving of at least one of the set of different functional units (22_n) when connected to the main body (14); a magnetic field sensor (34) mounted in a fixed position relative to the main body (14) for measuring at least one magnetic field parameter relating to a magnetic field at a fixed location relative to the main body when at least one of the set (20) of different functional units (22_n) is connected to the main body (14); and a controller (44) comprising a functional unit detection logic (46) which is configured to receive a set of inputs and generate, using the set of inputs, an output signal (47) associated with the selected one of the set (20) of different functional units (22_n) which is connected to the connection interface (16), wherein the set of inputs includes: a value (M_t) of the magnetic field parameter measured by the magnetic field sensor (34), a value (I_t) of the at least one current parameter measured by the current sensor (32), and a value (V_t) of the at least one vibration parameter measured by the vibration sensor.Claim 2. The personal care device drive unit as claimed in claim 1, wherein the functional unit detection logic (46) includes: at least a first detection pathway (72) in which the output signal (47) is generated in dependence upon the value (M_t) of the at least one magnetic field parameter measured by the magnetic field sensor (34); and at least a second detection pathway (74) in which the output signal (47) is generated in dependence upon the value of the at least one current parameter (I_t) measured by the current sensor (32) and / or the value of the at least one vibration parameter (V_t) measured by the vibration sensor (34);2024PF0014836 wherein the functional unit detection logic is configured to selectively follow the first detection pathway or the second detection pathway in dependence upon evaluation of a pre-defined condition.Claim 3. The personal care device drive unit (13) as claimed in claim 2, wherein the functional unit detection logic (46) is configured so as to selectively follow the first detection pathway (72) or the second detection pathway (74) in dependence upon: the measured value (M_t) of the at least one magnetic field parameter; the measured value (I_t) of the at least one current parameter; and / or the measured value (V_t) of the at least one vibration parameter.Claim 4. The personal care device drive unit (13) as claimed in claim 3, wherein the controller (44) comprises a memory (92) adapted to store a plurality of value ranges (A, B, C), and wherein the functional unit detection logic (46) is configured to selectively follow the first detection pathway (72) or the second detection pathway (74) in dependence upon which value range (A, B, C) of said plurality of value ranges the measured value (M_t) of the magnetic field parameter, the measured value (I_t) of the at least one current parameter and / or the measured value (V_t) of the at least one vibration parameter falls into.Claim 5. The personal care device drive unit (13) as claimed in any one of claims 1 to 4, wherein the controller (44) further includes a pressure detection logic (84) which is configured to generate an additional output signal (86) in dependence upon the value (M_t) of the magnetic field parameter measured by the magnetic field sensor (34), wherein the additional output signal (86) is associated with an external pressure (82) exerted on at least one of the set (20) of different functional units (22_n) when said at least one of the set of different functional units is connected to the main body (14).Claim 6. A personal care system (10) comprising a personal care device drive unit (13) as claimed in any one of claims 1 to 5 and a set (20) of different functional units (22_n) each being releasably connectable to the connection interface (16) of the main body (14) of the personal care device drive unit (13) and each comprising a movable functional component; wherein at least one of the set (20) of different functional units (22_n) includes a magnetic field modifier (52), wherein, when said at least one of the set (20) of different functional units (22_n) is connected to the main body (14), the magnetic field modifier (52) modifies the value (M_t) of the magnetic field parameter measured by the magnetic field sensor (34) into a predetermined value.2024PF0014837Claim 7. The personal care system as claimed in claim 6. wherein the magnetic field modifier (52) is a magnetic field source.Claim 8. The personal care system (10) as claimed in claim 6 or 7, wherein at least a first functional unit (22_1) of the set (20) of different functional units includes a first magnetic field modifier (52a); wherein at least a second functional unit (22_2) of the set of different functional units includes a second magnetic field modifier (52b); wherein the first magnetic field modifier (52a) is configured to modify the value (M_t) of the magnetic field parameter measured by the magnetic field sensor (34) into a first predetermined value; and wherein the second magnetic field modifier (52b) is configured to modify the value (M_t) of the magnetic field parameter measured by the magnetic field sensor (34) into a second predetermined value which is different from the first predetermined value.Claim 9. The system of claim 8, wherein the first magnetic field modifier (52a) comprises a first magnetic field source; the second magnetic field modifier (52b) comprises a second magnetic field source; the first magnetic field source has a first magnetic field polarity (- / +) measurable by the magnetic field sensor (34) when the first functional unit is connected to the connection interface; and the second magnetic field source has a second magnetic field polarity (+ / -) opposite to the first magnetic field polarity and measurable by the magnetic field sensor (34) when the second functional unit is connected to the connection interface.Claim 10. The personal care system (10) as claimed in claim 6 or 7, and comprising a personal care device drive unit (13) as claimed in claim 4, wherein the plurality of value ranges stored in the memory (92) of the controller (44) comprises a first value range into which the measured value (M_t) of the magnetic field parameter modified by said magnetic field modifier (52) falls.Claim 11. The personal care system (10) as claimed in claim 8 or 9 and comprising a personal care device drive unit (13) as claimed in claim 4, wherein the plurality of value ranges (A, B, C) stored in the memory (92) of the controller (44) comprises a first value range (A) into which the measured value (M_t) of the magnetic field parameter modified by said first magnetic field modifier (52a) falls, and a second value range (C) into which the measured value (M_t) of the magnetic field parameter modified by said second magnetic field modifier (52b) falls.2024PF0014838Claim 12. The personal care system (10) as claimed in any of claims 6-11 and comprising a personal care device drive unit (13) as claimed in claim 4, wherein the personal care system (10) further includes a pressure sensing subsystem (100) configured for sensing an external pressure (82) exerted during use on at least one of the set (20) of different functional units (22_n) when said at least one of the set of different functional units is connected to the main body (14), wherein the pressure sensing subsystem (100) includes: a further magnetic field source (102) mounted to the main body (14); and a displacement system (104) configured to generate a displacement of the further magnetic field source (102) relative to the magnetic field sensor (34) such that a distance (AD_1) between the further magnetic field source (102) of the pressure sensing subsystem (100) and the magnetic field sensor (34) and, therewith, a magnetic field strength measured by the magnetic field sensor (34) is dependent on said external pressure (82) according to a predefined relation.Claim 13. The personal care system (10) as claimed in any of claims 6-12, and comprising a personal care device drive unit (13) as claimed in claim 2, 3 or 4, wherein: the set (20) of different functional units comprises one functional unit (22_3) which is associated with the occurrence in the main body (14) of a maximum vibration amplitude above a predefined threshold value in a predefined range of vibration frequencies; the set (20) of different functional units comprises first (22_4) and second (22_5) further functional units which are each associated with the occurrence of a value (I_t) of the at least one current parameter in, respectively, mutually different first and second predefined ranges of the value of the at least one current parameter; wherein the second detection pathway (74) comprises: generating, at a first decision node (68), an output signal associated with said one functional unit (22 3) when a maximum vibration amplitude occurring within the predefined range of vibration frequencies and measured by the vibration sensor is above the predefined threshold value; or generating, at a second decision node (69), an output signal associated with the first or the second further functional unit when the value of the at least one current parameter measured by the current sensor is in, respectively, said first or said second predefined range of the value of the at least one current parameter.Claim 14. The personal care system of claim 13, wherein said one functional unit (22_3), comprises a functional component configured to perform a reciprocating motion, and said first (22 4) and second (22 5) further functional units each comprise a functional component configured to perform a rotating motion.2024PF0014839Claim 15. A computer-implemented method for identifying a selected one of a set (20) of different functional units (22_n) attached to a connection interface (16) of a main body (14) of a personal care device (12), the connection interface being adapted to enable connection of any selected one of the set (20) of different functional units (22_n) to the main body (14) so as to enable driving of a movable functional component of the selected one of the set of different functional units by a motor (18) included in the main body, the method comprising: measuring, by means of a current sensor (32), at least one current parameter relating to an electric current in the motor (18) when driving at least one of the set of different functional units (22_n) when connected to the main body (14); measuring, by means of a vibration sensor (36), at least one vibration parameter relating to a vibration of the main body (14) during driving of at least one of the set of different functional units when connected to the main body; measuring, by means of a magnetic field sensor, at least one magnetic field parameter relating to a magnetic field at a fixed location relative to the main body when at least one of the set of different functional units (22_n) is connected to the main body (14); receiving, by means of a functional unit detection logic (46) of a controller (44), a set of inputs; and generating (64), by means of the functional unit detection logic (46), an output signal (47) associated with the selected one of the set (20) of different functional units (22_n) which is connected to the connection interface (16) using the set of inputs; wherein the set of inputs includes: a value (M_t) of the magnetic field parameter measured by the magnetic field sensor (34), a value (I_t) of the at least one current parameter measured by the current sensor (32), and a value (V_t) of the at least one vibration parameter measured by the vibration sensor (36).

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