Method for determining the quantitative state of cleaning solution in a cleaning device for personal care devices.

Abstract

The present invention provides computer-implemented methods 201, 301 for determining the quantitative states QC1, QC2 of cleaning fluids 19, 119 in cleaning devices 1, 101 for personal care devices such as electric shavers 3, 103. The method includes steps 203, 207, 303 to control motors 23, 129 configured to drive liquid transfer members 21, 121 of the cleaning device to operate sequentially at at least two different motor speeds MS1, MS2, and steps 205, 209, 303 to receive sensor outputs SIM1, SIM2 related to currents IM1, IM2 in motors 23, 129 from sensors 65, 165 for each of the at least two different motor speeds. The method further includes steps 213, 307 of determining a value of a parameter PdI / dMS related to the degree to which the current in the motor changes based on the motor speed, based on the current in the motor for at least two different motor speeds, and steps 215, 309 of determining the quantitative state of the cleaning solution based on the determined value of the parameter and a predetermined relationship between the quantitative state and the parameter.

Description

Technical Field

[0001] The present invention relates to a computer-implemented method for determining a quantitative state of a cleaning liquid in a cleaning device for a personal care device, the quantitative state being related to the amount of cleaning liquid present in the cleaning device, the method comprising receiving from a sensor a sensor output related to a current in a motor configured to drive a liquid transfer member of the cleaning device, determining the current in the motor from the received sensor output, and determining the quantitative state based on the determined current in the motor and based on a predetermined relationship between the quantitative state and the current in the motor.

[0002] The present invention further relates to a cleaning device for a personal care device, which comprises a housing, a receiving chamber configured to receive at least a part of the personal care device to be cleaned at a cleaning position in the receiving chamber, a reservoir configured to hold a cleaning liquid, a liquid transfer member configured to transfer the cleaning liquid from the reservoir to the receiving chamber for cleaning the part of the personal care device, a motor configured to drive the liquid transfer member, a sensor configured to measure a current in the motor and provide a sensor output related to the measured current in the motor, and a processor configured to control the motor, receive the sensor output from the sensor, and determine a quantitative state of the cleaning liquid in the cleaning device based on the sensor output, the quantitative state being related to the amount of cleaning liquid present in the cleaning device.

[0003] The present invention further relates to a personal care system comprising a personal care device and a cleaning device for the personal care device, wherein the cleaning device comprises a housing, a receiving chamber configured to receive at least a portion of the personal care device to be cleaned at a cleaning position within the receiving chamber, a reservoir configured to hold a cleaning liquid, a liquid transfer member configured to transfer the cleaning liquid from the reservoir to the receiving chamber in order to clean the portion of the personal care device, and a driven coupling member connected to the liquid transfer member, wherein the personal care device comprises a motor, a sensor configured to measure the current in the motor and provide a sensor output related to the measured current in the motor, a driven coupling member connected to the motor, and a processor configured to control the motor and receive a sensor output from the sensor, wherein the driven coupling member of the cleaning device and the driven coupling member of the personal care device are configured and arranged to be interconnected at the cleaning position of the portion of the personal care device, and as a result, the liquid transfer member of the cleaning device is driveable by the motor of the personal care device. [Background technology]

[0004] Personal care devices configured to provide personalized care treatments to a specific body part are widely known. Examples include electric shavers for shaving facial hair, hair trimming devices for cutting facial hair or hair on other body parts, high-intensity pulsed light (IPL) devices for removing hair from legs or other body parts, facial brushing devices designed to cleanse the human face using rotating and / or vibrating brushes, skin rejuvenation devices designed to rejuvenate the skin on a human body part using electromagnetic or radio frequency energy, and toothbrushes designed to clean human teeth.

[0005] A personal care device can be used in conjunction with a cleaning device configured to clean at least a portion thereof. In particular, it may be desirable to clean the personal care treatment unit of a personal care device that provides actual personal care treatment to a body part in question. If the personal care device is, for example, an electric shaver, the cleaning device may be configured to clean the shaving unit of the electric shaver, which has one or more hair cutting units. In such a cleaning device, a cleaning solution is transferred from a reservoir to a receiving chamber by a liquid transfer member, such as a pump, where the part of the personal care device to be cleaned is placed. This generates a flow of cleaning solution along and / or through the part of the personal care device, resulting in the cleaning of the part. The cleaning device itself may have a motor that drives the liquid transfer member and a processor that controls the speed of the motor based on a predetermined cleaning program. In other systems, such as those disclosed in EP3737257B1 under the applicant's name, the liquid transfer member is driven by the motor of the personal care device, in this example the electric shaver, when the electric shaver is placed in the cleaning device. In this example, the shaver motor is controlled by the electric shaver's processor, and when the electric shaver is placed in the cleaning device, the processor can control the motor speed based on a predetermined cleaning program. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] When using such a cleaning device, it is useful for the user to be aware of the amount of cleaning fluid present in the device. If the amount of cleaning fluid is insufficient, the liquid transfer component may not be able to transfer a sufficient amount of cleaning fluid to the receiving chamber, or it may not be able to move any cleaning fluid at all. As a result, the personal care device may not be cleaned properly or may not be cleaned at all. For example, it is known that a transparent observation window may be provided in the housing of the cleaning device, through which the user can directly observe the level of cleaning fluid in the reservoir of the cleaning device. When the user observes that the cleaning fluid level is too low, the user can replenish the reservoir with new cleaning fluid or replace it with a full reservoir. A drawback of such an observation window is that the cleaning fluid may not be clearly visible through the window, especially in poor ambient lighting conditions. In other known examples, the cleaning fluid level is automatically detected by a liquid level sensor in the reservoir, and the user is automatically notified, for example, via the cleaning device's display or an audio feedback signal, if the cleaning fluid level is too low. However, such sensor-based automatic detection systems are complex and expensive.

[0007] Applicant EP3051975B1 discloses a cleaning device for an electric shaver, comprising a sensor for detecting current in a motor driving a liquid transfer member, and a processor configured to detect a low level of cleaning fluid in a reservoir based on the current in the motor detected by the sensor. In this known cleaning device, the processor compares the detected current value to a reference value corresponding to the current in the motor that occurs when the cleaning fluid level is sufficient. When the cleaning fluid level is sufficient, the liquid transfer member generates a standard continuous flow of cleaning fluid. When the cleaning fluid level is insufficient, the flow of cleaning fluid generated by the liquid transfer member is obstructed. The processor detects such turbulence in the cleaning fluid flow if the detected current value deviates from the reference value of the detected current by a predetermined threshold. When the processor detects such turbulence, it controls an indicator in the cleaning device to warn the user that the cleaning fluid level is insufficient. A drawback of this known cleaning device is that the current in the motor that occurs when the cleaning fluid level is sufficient may differ between cleaning devices, i.e., even if the cleaning devices have the same design and structure. Furthermore, in a particular sample of a cleaning device, the current in the motor generated when the cleaning fluid level is sufficient may fluctuate during the lifespan of the cleaning device, for example, as a result of wear or contamination. Consequently, determining the cleaning fluid level by comparing the absolute value of the motor current to a reference value may yield inaccurate results.

[0008] The object of the present invention is to provide a computerized method, a cleaning apparatus, and a personal care system having the features described in the preceding "Technical Field" section, thereby at least mitigating the problems associated with known cleaning apparatuses described in the preceding "Background Art" section. In particular, the object of the present invention is to provide a computerized method, a cleaning apparatus, and a personal care system in which the quantitative state of the cleaning fluid in the cleaning apparatus can be determined based on the measurement current of a motor driving a liquid transfer member, in a more reliable manner than the cleaning apparatus disclosed in EP3051975B1, and without using any sensor outputs generated or used in previous determinations of the quantitative state of the cleaning fluid. [Means for solving the problem]

[0009] According to a first aspect of the present invention, in order to achieve the above objective, a computer implementation method having the features described in the "Technical Field" section above further comprises the steps of: controlling a motor to operate sequentially at at least two different motor speeds; receiving a sensor output for each of the at least two different motor speeds; determining a current in the motor from the individually received sensor outputs for each of the at least two different motor speeds; determining a parameter value related to the degree to which the current in the motor changes based on the motor speed, based on the current in the motor determined for at least two different motor speeds; and determining the quantitative state of the cleaning solution based on the determined parameter value and a predetermined relationship between the quantitative state and the parameter.

[0010] As used in this book, the term “quantitative state of cleaning fluid” is intended to refer to the conditions or state that characterize the amount of cleaning fluid present in the cleaning apparatus. In addition to the absolute value of the amount of cleaning fluid, examples of “quantitative state” include, but are not limited to, sufficient quantity, sufficient level, insufficient quantity, insufficient level, full, or empty.

[0011] According to the method of the present invention, the current in the motor driving the liquid transfer member of the cleaning apparatus is measured at at least two different motor speeds. Based on these measurements, the values ​​of parameters related to the degree to which the current in the motor changes with respect to the motor speed are determined. As used herein, the expression "degree to which the current in the motor changes with respect to the motor speed" is intended to refer to the (average) change in the current in the motor associated with a given change in motor speed, in other words, the degree to which the current changes with respect to the change in motor speed. If the current can be expressed as a mathematical function of the motor speed, then "degree to which the current in the motor changes with respect to the motor speed" may be the mathematical derivative of that mathematical function. Examples of parameters related to the degree to which the current changes with respect to the motor speed are described below with reference to preferred embodiments of the present invention.

[0012] Surprisingly, the inventors of the present invention found that when the amount of cleaning fluid in the cleaning device is sufficient for the liquid transfer member to generate a continuous and uninterrupted flow of cleaning fluid from the reservoir to the receiving chamber, the current in the motor increases significantly with increasing motor speed. On the other hand, when the amount of cleaning fluid is insufficient for the liquid transfer member to generate a flow of cleaning fluid from the reservoir to the receiving chamber, the increase in current in the motor with increasing motor speed is not very significant. It was found that when the amount of cleaning fluid is sufficient, the significant increase in current with increasing motor speed occurs within a considerable sub-range of the motor speed range used in the cleaning programs of conventional cleaning devices. As a result, it was found that at least two different quantitative states of the cleaning fluid can be distinguished based on the value of the above parameter, which is associated with the degree to which the current in the motor changes based on motor speed. In particular, it was found that based on the above parameter, it is possible to distinguish between at least a first quantitative state that allows the liquid transfer member to generate an uninterrupted flow of cleaning fluid and a second quantitative state that does not allow the liquid transfer member to generate a flow of cleaning fluid. In particular, it appears possible to predetermine the relationship between the quantitative state and the above parameters, and as a result, in actual situations, the quantitative state of the cleaning solution can be determined based on the determined values ​​of the above parameters and the predetermined relationship. An example of the predetermined relationship is described below with reference to a preferred embodiment of the present invention. The determination of the quantitative state using the method according to the present invention has been confirmed to be robust and accurate throughout the lifespan of the cleaning device and has been found to provide uniform results for multiple different samples of cleaning devices of a particular design and structure. Since the determination of the quantitative state using the method according to the present invention is based solely on actual measurements of the current in the motor, this method does not need to rely on current values ​​that were, for example, performed during a previous cleaning session and stored in the processor's memory.

[0013] In one embodiment of the computer implementation method according to the present invention, the method further includes the step of providing a feedback signal to a feedback member related to a determined quantitative state of the cleaning solution and notifying the user of the cleaning device of the determined quantitative state. The feedback member may be, for example, a display of the cleaning device, a personal care device, or another device such as a smartphone that communicates data with the cleaning device and / or the personal care device.

[0014] In a preferred embodiment of the computer implementation method according to the present invention, the method includes the steps of determining that the cleaning solution has a first quantitative state when the determined value of a parameter is greater than or equal to a predetermined threshold, and determining that the cleaning solution has a second quantitative state different from the first quantitative state when the determined value of the parameter is less than a predetermined threshold. In this preferred embodiment, the predetermined relationship between the quantitative state and the parameter is relatively simple. That is, for any value of the parameter that is greater than or equal to the predetermined threshold, the quantitative state of the cleaning solution is the first quantitative state, and for any value of the parameter that is less than the predetermined threshold, the quantitative state of the cleaning solution is the second quantitative state. In particular, this preferred embodiment has been found to be suitable for situations in which the first and second quantitative states represent different ranges of the amount of cleaning solution, such as "sufficient amount" and "insufficient amount," or "amount greater than or equal to a predetermined threshold" and "amount less than or equal to a predetermined threshold."

[0015] In a preferred embodiment of the computer implementation method according to the present invention, the method comprises the steps of: controlling a motor to operate sequentially at a first motor speed and a second motor speed different from the first motor speed; receiving sensor outputs relating to the first motor speed and the second motor speed; and determining the current in the motor relating to the first motor speed and the second motor speed from the individually received sensor outputs, wherein the parameter is the difference between the currents in the motor determined for the first motor speed and the second motor speed. The inventors of the present invention have found that, for a sufficient amount of cleaning fluid, the increase in current is almost linear with respect to the increase in motor speed within a range of motor speeds in which the increase in current becomes significant with increasing motor speed. Therefore, by measuring the current only at two different motor speeds within this range, the degree to which the current in the motor changes based on the motor speed can be expressed fairly accurately by a relatively simple parameter, namely the difference in the currents in the motor determined for two different motor speeds. In this embodiment, if the determined difference is greater than or equal to a predetermined threshold, the cleaning fluid is determined to be in a first quantitative state, and if the determined difference is less than the predetermined threshold, the cleaning fluid is determined to be in a second quantitative state.

[0016] In a further preferred embodiment of the computer implementation method according to the present invention, the method comprises the steps of: controlling a motor to operate sequentially at a plurality of different motor speeds within a range of motor speeds; receiving sensor outputs for each of the plurality of different motor speeds; and determining the current in the motor for each of the plurality of different motor speeds from the individually received sensor outputs, wherein the parameter is the slope of a linear regression relationship between the plurality of different motor speeds and the current in the motor determined for each of the plurality of different motor speeds. By measuring the current at a plurality of different motor speeds, preferably three or more different motor speeds, the degree to which the current in the motor changes based on the motor speed can be expressed very accurately by the value of the slope of the linear regression relationship between the plurality of different motor speeds and the current determined for the plurality of different motor speeds. In this embodiment, if the determined value of the slope is greater than or equal to a predetermined threshold, the cleaning fluid is determined to be in a first quantitative state, and if the determined value of the slope is less than the predetermined threshold, the cleaning fluid is determined to be in a second quantitative state.

[0017] In a further embodiment of the computer implementation method according to the present invention, the method further comprises the steps of determining a coefficient of determination R2 related to a linear regression relationship, and determining that the cleaning fluid has a third quantitative state different from the first and second quantitative states if the coefficient of determination is less than a predetermined threshold. In embodiments in which the current in a motor is measured for a plurality of different motor speeds, this coefficient of determination is a measure of the degree of variation in the measured relationship between the current and the motor speed. A relatively large degree of variation, i.e., a relatively small value of the coefficient of determination, can indicate that the flow of the cleaning fluid is unstable, for example, that stability and interruption alternate. This can indicate a transition state from a relatively large amount of cleaning fluid, i.e., an amount sufficient for a stable flow of cleaning fluid, to a relatively small amount, i.e., an amount insufficient for the cleaning fluid to flow. Therefore, if the coefficient of determination is less than a predetermined threshold, it can be determined that the cleaning fluid has a third quantitative state different from the first and second quantitative states.

[0018] In yet another embodiment of the computer implementation method according to the present invention, the method includes the step of controlling a motor to progressively or linearly change the motor speed over a predetermined time interval from a first endpoint to a second endpoint of a range of motor speeds. By progressively or linearly changing the motor speed over a predetermined time period from the first endpoint to the second endpoint, the user experiences the changes in motor speed necessary to measure the current in the motor at a plurality of different motor speeds, but in a manner that is not intrusive or bothersome. During the progressive change in motor speed, when the motor speed reaches each of the plurality of motor speeds for which measurement is required, the current in the motor can be measured and recorded by the processor.

[0019] According to a second aspect of the present invention, a computer program product is provided which includes a non-temporary computer-readable medium. The computer-readable medium has computer-readable code embodied therein, which, when executed by a suitable computer or processor, is configured to cause the computer or processor to execute a method according to the present invention or any embodiment of the method described above.

[0020] According to a third aspect of the present invention, in order to achieve the above objective, a cleaning apparatus having the features described in the "Technical Field" section is characterized in that the processor of the cleaning apparatus is configured to perform the method according to the present invention or any embodiment thereof described above in order to determine the quantitative state of the cleaning liquid in the cleaning apparatus.

[0021] According to a fourth aspect of the present invention, in order to achieve the above objective, a personal care system having the features described in the preceding "Technical Field" section is characterized in that the processor of the personal care device of the personal care system is configured to perform the method of the present invention or a method according to any embodiment thereof to determine the quantitative state of the cleaning solution in the cleaning device, wherein the quantitative state is related to the amount of cleaning solution present in the cleaning device.

[0022] In the personal care system according to the present invention, a driven coupling member of the cleaning device and a driven coupling member of the personal care device are coupled to each other at the cleaning position of the personal care device within the receiving chamber of the cleaning device, and as a result, the liquid transfer member of the cleaning device can be driven by the motor of the personal care device via the driven coupling member and the driven coupling member. Consequently, the processor and motor of the personal care device can control and drive the liquid transfer member of the cleaning device and execute a predetermined cleaning program for cleaning the personal care device. Therefore, this cleaning device does not require any electrical or electronic elements and can have a relatively simple design consisting only of mechanical elements. Typically, a personal care device already has a sensor for measuring the current in its motor, and this sensor can be used by the processor of the personal care device to perform the method of the present invention for determining the quantitative state of the cleaning fluid in the cleaning device. Therefore, in the personal care system according to the present invention, the processor of the personal care device can be configured to perform the method of the present invention without using any additional dedicated sensors.

[0023] In embodiments of the cleaning apparatus and personal care system according to the present invention, the processor is configured to control the rotational speed of the motor as a function of time based on a predetermined cleaning program, and after controlling the motor based on the predetermined cleaning program, to control the motor to operate sequentially at at least two different motor speeds in order to determine the quantitative state of the cleaning fluid. In these embodiments, the quantitative state of the cleaning fluid in the cleaning apparatus is determined after the completion of the predetermined cleaning program, and as a result, the part of the personal care device to be cleaned becomes clean. Consequently, the influence of the presence of any foreign matter in the part of the personal care device on the motor current measurement with respect to the determination of the quantitative state is limited. In particular, the quantitative state can be determined with sufficient accuracy immediately after the cleaning program, i.e., without removing the personal care device from the cleaning apparatus.

[0024] In an embodiment of a cleaning device and a personal care system according to the present invention, the personal care device is an electric shaver having a main body and a shaving unit coupled to the main body, and a receiving chamber of the cleaning device is configured to receive the shaving unit of the electric shaver at a cleaning position within the cleaning chamber. However, the cleaning device according to the present invention can also be used to clean other types of personal care devices or parts thereof, and the personal care system according to the present invention can have another type of personal care device, such as any of the types of personal care devices described above in the "Background Art" section.

[0025] In a further embodiment of a cleaning device and a personal care system according to the present invention, the shaving unit has at least one hair cutting unit, which has an external cutting member with a hair introduction opening and an internal cutting member covered by the external cutting member and movable relative to the external cutting member, and the cleaning device has, for each hair cutting unit, at least one liquid injection nozzle configured and arranged within the receiving chamber, and provides a jet of cleaning liquid that propagates directly into the individual hair cutting units through at least one hair introduction opening when the shaving unit is in the cleaning position. In these embodiments, each liquid injection nozzle generates a flow of cleaning liquid through the associated hair cutting unit of the shaving unit within the receiving chamber of the cleaning device. This provides thorough cleaning of the hair cutting units of the shaving unit. Further, it has been found that, due to the flow of the cleaning liquid through the hair cutting units, when the amount of cleaning liquid in the cleaning device is sufficient for the liquid transfer member to generate a continuous and uninterrupted flow of cleaning liquid from the reservoir to the receiving chamber, the degree of increase in the current within the motor associated with an increase in the motor speed becomes even more pronounced.

[0026] The above and other aspects of the present invention will become apparent from the following detailed description of embodiments of a computer-implemented method, a cleaning device, and a personal care system according to the present invention, which will be described with reference thereto.

Brief Description of the Drawings

[0027] [Figure 1] This is a diagram showing a cross-section of an embodiment of the cleaning device according to the present invention. [Figure 2] This is a diagram schematically showing an embodiment of the personal care system according to the present invention. [Figure 3] This is a diagram showing the cleaning device of the personal care system in FIG. 2 in a top view. [Figure 4] This is a diagram showing the shaving unit of the electric shaver of the personal care system in FIG. 2 in a top view. [Figure 5] This is a diagram schematically showing a block diagram of the control system of the cleaning device in FIG. 1 and the personal care system in FIG. 2. [Figure 6] This is a flowchart of a first embodiment of a computer-implemented method according to the present invention for determining the quantitative state of the cleaning liquid in the cleaning devices of FIGS. 1 and 3. [Figure 7] This is a diagram showing the measured current in the motor of the electric shaver of the personal care system as a function of the motor speed when driving the cleaning device of the personal care system used in the method of FIG. 6 for the personal care system in FIG. 2. [Figure 8] This is a flowchart of a second embodiment of a computer-implemented method according to the present invention for determining the quantitative state of the cleaning liquid in the cleaning devices of FIGS. 1 and 3. [Figure 9] This is a diagram showing the measured current in the motor of the electric shaver of the personal care system as a function of the motor speed when driving the cleaning device of the personal care system used in the method of FIG. 8 for the personal care system in FIG. 2. [Figure 10] This is a diagram showing the measured current in the motor of the electric shaver of the personal care system during the cleaning program of the cleaning device of the personal care system executed according to the method of FIG. 6 for the personal care system in FIG. 2. [Figure 11]Figure 2 shows the personal care system, and the figure shows the current measured in the motor of the electric shaver of the personal care system during the cleaning program of the cleaning device of the personal care system, which is performed according to the method in Figure 8. [Modes for carrying out the invention]

[0028] The present invention will be described in more detail with reference to the figures. In the figures, equivalent or similar features are indicated by the same reference numerals.

[0029] Figure 1 shows a cross-section of an embodiment of the cleaning device 1 according to the present invention. The cleaning device 1 is configured to clean a personal care device, in this embodiment, an electric shaver 3. In particular, in this embodiment, the cleaning device 1 is configured to clean the shaving unit 5 of the electric shaver 3. In this embodiment, the shaving unit 5 has three rotary hair cutting units 7 and is coupled to the body 9 of the electric shaver 3, which is intended to be held in the user's hand when the electric shaver 3 is in use. Figure 1 shows a partial view of the hair cutting units 7. Electric shavers with rotary hair cutting units are known to those skilled in the art. Therefore, further detailed description of the electric shaver 3, the shaving unit 5, and the hair cutting units 7 is omitted.

[0030] It should be noted that the present invention also covers embodiments of cleaning devices for cleaning personal care devices of a different type than electric shaver 3. Such personal care devices are, for example, linear reciprocating electric shavers, or non-electric hair cutting devices such as hair trimming devices, blade razors, high-intensity pulsed light (IPL) devices, facial brushing devices, toothbrushes, or skin rejuvenation devices using light or high-frequency energy, which are different types of personal care devices from electric shavers. All of these types of personal care devices are known to those skilled in the art. Such personal care devices may have a main body and a personal care treatment unit that is located in the main body and configured to provide personal care treatment to a part of the user's body. The cleaning device according to the present invention may be configured to clean at least a part of the personal care device, in particular at least a part of the personal care treatment unit.

[0031] As shown in Figure 1, the cleaning device 1 has a housing 11. A receiving chamber 13 is provided within the housing 11. The receiving chamber 13 is configured to receive at least a portion of the shaving unit 5, particularly a portion of the shaving unit 5 including the hair cutting unit 7. For this purpose, the cleaning device 1 has a holder 15 configured to grip and hold the body 9 of the electric shaver 3, so that the shaving unit 5 is held in a stationary cleaning position within the receiving chamber 13. The holder 15 is connected to or part of the housing 11 of the cleaning device 1. The user can easily install the electric shaver 3 into the cleaning device 1 by placing the body 9 into the holder 15, and can easily remove the electric shaver 3 from the cleaning device 1 by removing the body 9 from the holder 15. Generally, in the cleaning device according to the present invention, the receiving chamber is configured to receive at least a portion of the personal care device to be cleaned in a cleaning position within the receiving chamber.

[0032] As shown in Figure 1, a reservoir 17 is located within the housing 11. The reservoir 17 is configured to hold cleaning fluid 19. In the embodiment shown in Figure 1, for example, if, after repeated use of the cleaning device 1, the amount or level of cleaning fluid 19 remaining in the reservoir 17 is too low, or if the degree of contamination of the remaining cleaning fluid 19 is too high, the reservoir 17 can be removed from the cleaning device 1. For this purpose, the user can lift the housing 11, including all other components of the cleaning device 1, from the reservoir 17 and place the housing 11 on a replacement reservoir containing new cleaning fluid. In other embodiments, the reservoir is integrally formed with the housing of the cleaning device, and the housing and / or reservoir are provided with, for example, a suitable openable and closable opening that allows the user to replenish the reservoir with new cleaning fluid.

[0033] As shown in Figure 1, the cleaning device 1 further includes a liquid transfer member 21 and an electric motor 23 configured and positioned to drive the liquid transfer member 21. The liquid transfer member 21 is configured to transfer cleaning fluid 19 from the reservoir 17 to the receiving chamber 13 in order to clean the shaving unit 5. In the embodiment shown in Figure 1, the liquid transfer member 21 has an impeller wheel 25 attached to the drive shaft 27 of the electric motor 23. The impeller wheel 25 is located at the bottom of a fluid passage 29 connecting the reservoir 17 and the receiving chamber 13. The electric motor 23 is located in a waterproof motor chamber 31 within the housing 11. During use, the action of the impeller wheel 25 moves the cleaning fluid 19 from the reservoir 17 to the receiving chamber 13 via the fluid passage 29. The receiving chamber 13 has an overflow opening 33 that defines the maximum liquid level height of the cleaning fluid 19 in the receiving chamber 13. The cleaning fluid 19 is allowed to flow back into the reservoir 17 from the receiving chamber 13 via the overflow opening 33 and the return passage 35. A filter 37 is placed inside the reservoir 17 to remove any contaminants present in the flow of cleaning fluid 19.

[0034] The cleaning device 1 further includes a processor 61 configured to control an electric motor 23. In an embodiment of the cleaning device 1, the processor 61 is housed within the housing 11 of the cleaning device 1, as schematically shown in Figure 1. In particular, the processor 61 is configured, for example, to control the rotational speed of the electric motor 23 as a function of time based on a predetermined cleaning program. As is known to those skilled in the art, the cleaning program may have a plurality of consecutive cleaning phases separated by interruption phases. In each cleaning phase, the electric motor 23 may be driven for a predetermined time period and / or a predetermined motor speed, the predetermined time period and / or predetermined motor speed may differ for each different cleaning phase. During the interruption phase, the electric motor 23 is not driven. The user can start the cleaning program using a user interface (not shown in Figure 1) provided in the housing 11. Alternatively, the user can start the cleaning program using a remote device (e.g., a smartphone) that communicates with the cleaning device 1 (e.g., wirelessly) for data. The user can receive notifications about the progress of the cleaning program via the same user interface or remote device.

[0035] Figure 2 schematically shows an embodiment of the personal care system 100 according to the present invention. The personal care system 100 comprises a personal care device, in this embodiment an electric shaver 103, and a cleaning device 101 for the electric shaver 103. In particular, in this embodiment, the cleaning device 101 is configured to clean the shaving unit 105 of the electric shaver 103. In this embodiment, the shaving unit 105 has three rotary hair cutting units 107 and is coupled to the body 109 of the electric shaver 103, which is intended to be held in the user's hand when the electric shaver 103 is in use. Figure 2 shows a portion of the hair cutting units 107. The present invention also covers embodiments of a personal care system having a cleaning device and a personal care device of a different type than the electric shaver 103, as described above with respect to an embodiment of the cleaning device 1 according to the present invention.

[0036] As shown in Figure 2, the cleaning device 101 of the personal care system 100 has a housing 111. A receiving chamber 113 is provided within the housing 111. The receiving chamber 113 is configured to receive at least a portion of the shaving unit 105 of the electric shaver 103, particularly a portion of the shaving unit 105 including the hair cutting unit 107. For this purpose, the cleaning device 101 may have a holder (not shown in Figure 2) similar to the holder 15 of the cleaning device 1 described above, and is configured to grip and hold the body 109 of the electric shaver 103. As a result, the shaving unit 105 is held in a stationary cleaning position within the receiving chamber 113. The user can easily place the electric shaver 103 into the cleaning device 101 to clean the shaving unit 105, and can easily remove the electric shaver 103 from the cleaning device 101 after the cleaning process.

[0037] As shown in Figure 2, a reservoir 117 is located inside the housing 111 of the cleaning device 101. The reservoir 117 is configured to hold cleaning fluid 119. Similar to the reservoir 17 of the cleaning device 1 described above, the reservoir 117 can be detachably located inside the housing 111 or can be formed integrally with the housing 111.

[0038] As shown in Figure 2, the cleaning device 101 of the personal care system 100 further includes a liquid transfer member 121 configured to transfer cleaning fluid 119 from the reservoir 117 to the receiving chamber 113 in order to clean the cleaning unit 105. In the embodiment shown in Figure 2, the liquid transfer member 121 has an impeller wheel 123 attached to the drive shaft 125. The impeller wheel 123 is located at the bottom of the fluid passage 127 connecting the reservoir 117 and the receiving chamber 113.

[0039] The personal care system 100 is of the type disclosed in applicant EP3737257B1 and EP3924153B1, and as shown in Figure 2, when the shaving unit 105 of the electric shaver 103 is in the cleaning position in the receiving chamber 113 of the cleaning device 101, the liquid transfer member 121 of the cleaning device 101 is drivable by the electric motor 129 of the electric shaver 103. For this purpose, the cleaning device 101 has a driven coupling member 131 connected to the impeller wheel 123 of the liquid transfer member 121 via a drive shaft 125. The shaving unit 105 of the electric shaver 103 has a driving coupling member 133 connected to the electric motor 129 of the electric shaver 103. Figure 2 merely schematically shows that the electric motor 129 is located in the body 109 of the electric shaver 103 and the driving coupling member 133 is connected to the electric motor 129 via a drive shaft 135 in the electric shaver 103. Further details regarding the connection between the drive coupling member 133 and the electric motor 129 are described in EP3737257B1.

[0040] Figure 2 shows only a schematic representation of the driven coupling member 131 of the cleaning device 101 and the drive coupling member 133 of the shaving unit 105. As shown in Figure 4, the drive coupling member 133 is positioned at the center 137 between the three hair cutting units 107 of the shaving unit 105. As shown in Figure 3, the driven coupling member 131 is positioned at the center of the bottom wall 139 of the receiving chamber 113 of the cleaning device 101. Thus, the driven coupling member 131 of the cleaning device 101 and the drive coupling member 133 of the electric shaver 103 are configured to be coupled to each other when the shaving unit 105 is in the cleaning position within the receiving chamber 113, and as a result, the liquid transfer member 121 of the cleaning device 101 can be driven by the electric motor 129 of the electric shaver 103.

[0041] As shown in Figures 2 and 4, each hair cutting unit 107 has, in a manner well known to those skilled in the art, an external cutting member 141 having a hair introduction opening 143 and an internal cutting member 145 having a cutting element 147 covered by the external cutting member 141. The internal cutting member 145 of each hair cutting unit 107 is movable, in particular rotatable, relative to the external cutting member 141 via a drive shaft 135 and a transmission unit 149 by an electric motor 129 of the electric shaver 103, the transmission unit being located inside the shaving unit 105 and coupled to the drive shaft 135 and the internal cutting member 145.

[0042] In the embodiment shown in Figure 2, the fluid passage 127 is connected to a plenum chamber 151 integrally formed with the bottom wall 139 of the receiving chamber 113. The cleaning device 101 has at least one liquid spray nozzle 153 located in the bottom wall 139 that is in fluid communication with the plenum chamber 151 for each of the three hair cutting units 107 of the shaving unit 105. As shown in Figure 3, in this embodiment, each of the three hair cutting units 107 is provided with a single liquid spray nozzle 153 (shown schematically only). Each liquid spray nozzle 153 is configured and positioned in the bottom wall 139 of the receiving chamber 113, and when the shaving unit 105 is in the cleaning position within the receiving chamber 113 and the liquid transfer member 121 is driven by the electric motor 129, a jet of cleaning fluid 119 is propagated into the hair cutting unit 107 associated with the liquid spray nozzle 153, directly penetrating at least one of the hair introduction openings 143 of the external cutting member 141. After flowing through the hair cutting unit 107, the cleaning solution 119 leaves the hair cutting unit 107 again via a portion of the hair introduction opening 143 of the external cutting member 141, and is able to flow back to the reservoir 117 via a return opening 155 provided in the bottom wall 139 of the receiving chamber 113, as shown in Figure 2.

[0043] The electric shaver 103 of the personal care system 100 further includes a processor 161 configured to control an electric motor 129. In an embodiment of the personal care system 100, the processor 161 is housed within the body 109 of the electric shaver 103, as schematically shown in Figure 2. During a shaving session, i.e., when the electric shaver 103 is not placed in the cleaning unit 101, the processor 161 can control the electric motor 129 to operate at a predetermined motor speed optimal for the shaving process, as is well known to those skilled in the art. When the electric shaver 103 is placed in the cleaning unit 101, the processor 161 receives a position signal from a position sensor 163 located within the body 109 of the electric shaver 103, as schematically shown in Figure 2. In this embodiment, the position sensor 163 is an orientation sensor configured to detect a characteristic orientation of the body 109 of the electric shaver 103 with respect to the Earth's gravitational field when the shaving unit 105 of the electric shaver 103 is in the cleaning position within the cleaning chamber 113 of the cleaning unit 101. Further details of the position sensor 163 and its use for detecting the presence of the electric shaver 103 in the cleaning device 101 are described in EP3771528A1 in the name of the applicant.

[0044] As described above, when the position sensor 163 detects that the electric shaver 103 is inside the cleaning device 101, the processor 161 is configured, for example, to control the rotational speed of the electric motor 129 as a function of time based on a predetermined cleaning program. The cleaning program can be of the same type as described above for the cleaning device 1. The user can start the cleaning program using a user interface (not shown in Figure 2) provided on the main body 109 of the electric shaver 103. Alternatively, the user can start the cleaning program using a remote device (e.g., a smartphone) that is communicating with the electric shaver 103 (e.g., wirelessly). Alternatively, when the position sensor 163 detects that the electric shaver 103 is inside the cleaning device 101, the processor 161 can automatically start the cleaning program. The user can receive notifications about the progress of the cleaning program via the same user interface or remote device.

[0045] According to the present invention, the processor 61 of the cleaning device 1 described above with reference to Figure 1, and the processor 161 of the electric shaver 103 of the personal care system 100 described above with reference to Figures 2-4, are each configured, for example, to execute, i.e., implement, the computer implementation method according to the present invention to determine the quantitative state of the cleaning fluids 19 and 119 in the cleaning devices 1 and 101, and are programmed accordingly. In particular, according to this method, the quantitative state of the cleaning fluids 19 and 119 in the cleaning devices 1 and 101 is determined based on the determined current in the electric motors 23 and 129. That is, when the electric motors 23 and 129 are driving the liquid transfer members 21 and 121 of the cleaning devices 1 and 101, the quantitative state of the cleaning fluids 19 and 119 is determined based on a predetermined relationship between the current in the electric motors 23 and 129. For this purpose, the cleaning device 1 and the electric shaver 103 each have sensors 65 and 165 configured to measure the current in the electric motors 23 and 129 and to provide a sensor output SIM related to the measured current in the electric motors 23 and 129. Sensors 65 and 165 are schematically shown in Figures 1 and 2.

[0046] The block diagram in Figure 5 schematically shows that in the control system for the electric motors 23 and 129 of the electric shaver 103 of the cleaning device 1 and personal care system 100, processors 61 and 161 are configured to receive sensor output SIMs from sensors 65 and 165. Based on the sensor output SIMs, processors 61 and 161 are configured to determine the quantitative state of the cleaning fluids 19 and 119 in the cleaning device 1 and 101. In the embodiment shown in Figure 5, processors 61 and 161 are further configured to provide feedback signals SQCs related to the determined quantitative state of the cleaning fluids 19 and 119 to the respective feedback members 67 and 167 of the cleaning device 1 and electric shaver 103, respectively, and to notify the user of the determined quantitative state of the cleaning fluids 19 and 119. Feedback members 67 and 167, which are not shown in Figures 1 and 2, may have displays. Alternatively, the feedback members may be part of a remote device that communicates data with the cleaning device 1 or electric shaver 103, such as a smartphone.

[0047] Figure 5 further shows that processors 61 and 161 are configured to provide an output signal SMS to motor drivers 69 and 169 configured to supply current IM to electric motors 23 and 129 based on the output signal SMS. In the illustrated embodiment, the output signal SMS represents the required motor speed MS of the electric motors 23 and 129. The motor drivers 69 and 169 are configured to control the current IM in a manner known to those skilled in the art, so that the electric motors 23 and 129 operate at the motor speed MS represented by the output signal SMS.

[0048] A first embodiment of the computer implementation method 201 according to the present invention, which is performed by processors 61 and 161 to determine the quantitative state of the cleaning fluids 19 and 119 in cleaning devices 1 and 101, is shown in the flowchart of Figure 6. In the first step 203 of method 201, the electric motors 23 and 129 are controlled to operate at a first motor speed MS1 by supplying an output signal SMS1, in particular representing a first motor speed MS1, to the motor drivers 69 and 169. In the second step 205 of method 201, a sensor output SIM1 is received from sensors 65 and 165, which represents the current IM1 in the electric motors 23 and 129 measured at the first motor speed MS1. In the third step 207 of method 201, the electric motors 23 and 129 are controlled to operate at a second motor speed MS2, which is different from the first motor speed MS1, by supplying an output signal SMS2, in particular representing a second motor speed MS2, to the motor drivers 69 and 169. In the fourth step 209 of Method 201, a sensor output SIM2 is received from sensors 65 and 165, which represents the current IM2 in motors 23 and 129 measured at a second motor speed MS2. In the first embodiment of Method 201 shown in Figure 6, the second motor speed MS2 is greater than the first motor speed MS1. In the fifth step 211 of Method 201, the currents IM1 and IM2 in electric motors 23 and 129 for the first motor speed MS1 and the second motor speed MS2, respectively, are determined from the received sensor outputs SIM1 and SIM2.

[0049] In step 213 of method 201, the value of the parameter PdI / dMS is determined based on the currents IM1 and IM2 determined for the first and second motor speeds MS1 and MS2. The parameter PdI / dMS is related to the extent to which the current IM in the electric motors 23 and 129 changes according to the motor speed. In the first embodiment of method 201 shown in Figure 6, the parameter PdI / dMS is the difference IM2-IM1 between the currents IM1 and IM2 determined for the first and second motor speeds MS1 and MS2. In step 215 of method 201, the quantitative state of the cleaning fluids 19 and 119 in the cleaning devices 1 and 101 is determined based on the determined value of the parameter PdI / dMS, i.e., the determined difference IM2-IM1, and based on a predetermined relationship between the quantitative state of the cleaning fluids 19 and 119 and the parameter PdI / dMS. In the first embodiment of method 201 shown in Figure 6, the predetermined relationship stipulates that when the determined value of the parameter PdI / dMS, in this embodiment the difference IM2-IM1, is greater than or equal to a first threshold PTH1, the cleaning solutions 19 and 119 have a first quantitative state QC1, and when the determined value of the parameter PdI / dMS, in this embodiment the difference IM2-IM1, is less than the first threshold PTH1, the cleaning solutions 19 and 119 have a second quantitative state QC2 that is different from the first quantitative state QC1. In particular, in the first embodiment of method 201, the first quantitative state QC1 corresponds to the amount of cleaning solutions 19 and 119 that enables the generation of a continuous flow of cleaning solutions 19 and 119 by the liquid transfer members 21 and 121, and is indicated to the user as "sufficient". The second quantitative condition QC2 corresponds to the amount of cleaning liquid 19, 119 that does not allow the liquid transfer members 21, 121 to generate a flow of cleaning liquid 19, 119, and is indicated to the user as "insufficient".

[0050] In the eighth step 217 of method 201, as described above, a feedback signal SQC related to the determined quantitative state of the cleaning solutions 19, 119, i.e., the first or second quantitative state QC1, QC2, is provided to the feedback members 67, 167 to notify the user of the cleaning device 1, 101 of the determined quantitative state.

[0051] Figure 7 shows the measured current IM of the electric motor 129 of the electric shaver 103 as a function of the motor speed MS when the electric motor 129 is driving the liquid transfer member 121 of the cleaning device 101, i.e., in the cleaning position of the electric shaver 103 as shown in Figure 2, for an embodiment of the personal care system 100 shown in Figure 2. In particular, Figure 7 shows the measured current IM for the first quantitative state QC1 of the cleaning liquid 119 in the cleaning device 101 described above, which corresponds to a sufficient amount of cleaning liquid 119 to enable the liquid transfer member 121 to generate a continuous and uninterrupted flow of cleaning liquid 119 from the reservoir 117 to the receiving chamber 113. Figure 7 also shows the measured current for the second quantitative state QC2 of the cleaning liquid 119 in the cleaning device 101 described above, which corresponds to a quantity of cleaning liquid 119 that is insufficient to enable the liquid transfer member 121 to generate a flow of cleaning liquid 119 from the reservoir 117 to the receiving chamber 113. As shown in Figure 7, for the first quantitative state QC1, the measured current IM increases significantly with increasing motor speed MS. For the second quantitative state QC2, the increase in the measured current IM with increasing motor speed MS is not very significant.

[0052] As shown in Figure 7, in an embodiment of the personal care system 100, for a first quantitative state QC1, i.e., for a sufficient amount of cleaning fluid 119 for a normal and uninterrupted flow of cleaning fluid 119 in the cleaning device 101, a significant increase in current IM with increasing motor speed MS occurs within a substantial sub-range PRMS within the range of motor speed MS. It should be noted that the motor speed MS applied during the cleaning program of the cleaning device 101 typically falls within the above sub-range PRMS. Furthermore, Figure 7 shows that within this sub-range PRMS, the increase in current IM is approximately linear with respect to the increase in motor speed MS. Therefore, based on the first embodiment of method 201 described above, by measuring the current IM only at two different motor speeds MS1 and MS2 within this sub-range PRMS, the degree to which the current IM in the motor 129 changes based on the motor speed MS can be accurately represented by the relatively simple parameter PdI / dMS used in the first embodiment of method 201, i.e., the difference IM2-IM1 between currents IM1 and IM2 determined for the two different motor speeds MS1 and MS2 as described above. In the embodiment shown in Figure 7, the first motor speed MS1 is approximately 5600 rpm, and the second motor speed MS2 is approximately 7300 rpm. As shown in Figure 7, the difference IM2-IM1 for the first quantitative state QC1 is significantly larger than the difference IM2-IM1 for the second quantitative state QC2. As a result, in the first embodiment of Method 201, the first quantitative state QC1 can be easily and robustly distinguished from the second quantitative state QC2 by determining whether the measurement difference IM2-IM1 is greater than or less than the first predetermined threshold PTH1, as described above. Those skilled in the art should note that an appropriate value for the first threshold PTH1 can be determined based on a simple and straightforward experiment.

[0053] A second embodiment of the computer implementation method 301 according to the present invention for determining the quantitative state of cleaning fluids 19, 119 in cleaning devices 1, 101, which is performed by processors 61, 161, is shown in the flowchart of Figure 8. In the first embodiment of method 201, electric motors 23, 129 are controlled to operate at only two different motor speeds MS1, MS2, and sensor outputs SIM1, SIM2 are received from sensors 65, 165 only at these two different motor speeds MS1, MS2. In the second embodiment of method 301, electric motors 23, 129 are controlled to operate sequentially at N different motor speeds MS1, MS2, ..., MSN by sequentially supplying output signals SMS1, SMS2, ..., SMSN, each representing N different motor speeds, to motor drivers 69, 169 within a range of motor speeds PMS. As a result, sensor outputs SIM1, SIM2, ..., SIMN, representing the currents IM1, IM2, ..., IMN measured at N different motor speeds in motors 23, 129, are sequentially received from sensors 65, 165 for each of the N different motor speeds. For simplicity, the flowchart in Figure 8 shows the steps of controlling the electric motors 23, 129 to operate at N different motor speeds and receiving the sensor output SIM for each of the N different motor speeds as a single first step 303 of method 301.

[0054] Preferably, in the first step 303 of Method 301, the electric motors 23, 129 are controlled to change the motor speed MS progressively or linearly over a predetermined time period from a first endpoint MS1 to a second endpoint MSN within the motor speed range PMS. As a result, the user experiences that the motor speed MS required to measure the current IM in the electric motors 23, 129 changes within N different motor speeds MS1, MS2, ..., MSN within the motor speed range PMS, but this is not disruptive or inconvenient. During the progressive change of the motor speed MS, the currents IM1, IM2, ..., IMN in the motors 23, 129 can be measured and recorded in the first step 303 of Method 301 as the motor speed MS reaches each of the N different motor speeds MS1, MS2, ..., MSN.

[0055] In the second step 305 of method 301, the currents IM1, IM2, ..., IIMN in the electric motors 23, 129 for N different motor speeds MS1, MS2, ..., MSN are determined from the received sensor outputs SIM1, SIM2, ..., SIMN, respectively.

[0056] In the third step 307 of Method 301, the value of the parameter PdI / dMS is determined based on the currents IM1, IM2, ..., IIMN determined for N different motor speeds MS1, MS2, ..., MSN. In the second embodiment of Method 301 shown in Figure 8, the parameter PdI / dMS is the slope dI / dMS of the linear regression relationship between the N different motor speeds MS1, MS2, ..., MSN and the currents IM1, IM2, ..., IMN determined for each of the N different motor speeds.

[0057] In the fourth step 309 of Method 301, the quantitative state of the cleaning solutions 19 and 119 in the cleaning devices 1 and 101 is determined based on the determined value of the parameter PdI / dMS, i.e., the determined value of the slope dl / dMS, and based on a predetermined relationship between the quantitative state of the cleaning solutions 19 and 119 and the parameter PdI / dMS. In the second embodiment of Method 301 shown in Figure 8, the predetermined relationship specifies that when the determined value of the parameter PdI / dMS, in this embodiment the slope dl / dMS, is greater than or equal to a predetermined second threshold PTH2, the cleaning solutions 19 and 119 have a first quantitative state QC1, and when the determined value of the parameter PdI / dMS, in this embodiment the slope dI / dMS, is less than a predetermined second threshold PTH2, the cleaning solutions 19 and 119 have a second quantitative state QC2 that is different from the first quantitative state QC1. Similar to the first embodiment of Method 201 described above, in the second embodiment of Method 301, the first quantitative state QC1 corresponds to the amount of cleaning liquid 19, 119 that enables the generation of a continuous flow of cleaning liquid 19, 119 by the liquid transfer members 21, 121, and this is indicated to the user as "sufficient". The second quantitative state QC2 corresponds to the amount of cleaning liquid 19, 119 that does not enable the generation of a flow of cleaning liquid 19, 119 by the liquid transfer members 21, 121, and this is indicated to the user as "insufficient".

[0058] Optionally, in the fifth step 311 of Method 301, the coefficient of determination R2 is determined, which relates to the linear regression relationship between N different motor speeds MS1, MS2, ..., MSN and the currents IM1, IM2, ..., IMN determined for each of the N different motor speeds, as determined in the third step 307 of Method 301. In any sixth step 313 of Method 301, if the determined coefficient of determination R2 is below a predetermined third threshold PTHS, it is determined that the cleaning fluids 19, 119 in the cleaning devices 1, 101 have a third quantitative state QC3 that is different from the first and second quantitative states QC1, QC2 described in relation to the fourth step 309 of Method 301. Instead of the coefficient of determination R2, a different correlation coefficient, such as the Pearson coefficient, can be determined. In the fifth and sixth optional steps 311 and 313 of the second embodiment of Method 301, the third quantitative state QC3 corresponds to a transition state of the amount of cleaning fluids 19 and 119 in the cleaning devices 1 and 101, from a first quantitative state QC1 sufficient for a continuous and uninterrupted flow of cleaning fluids 19 and 119 in the cleaning devices 1 and 101, to a second quantitative state QC2 insufficient for the flow of cleaning fluids 19 and 119 in the cleaning devices 1 and 101.

[0059] In step 315 of method 301, as described above, a feedback signal SQC related to the determined quantitative state of the cleaning solutions 19, 119, i.e., the first or second quantitative state QC1, QC2, or optionally the third quantitative state QC3, is provided to the feedback members 67, 167, and the determined quantitative state is notified to the user of the cleaning device 1, 101.

[0060] Similar to FIG. 7, FIG. 9 shows, for the embodiment of the personal care system 100 shown in FIG. 2 and for the first and second quantitative states QC1 and QC2 of the cleaning liquid 119 in the cleaning device 101 described above, the measured current IM in the electric motor 129 of the electric shaver 103 as a function of the motor speed MS when the electric motor 129 drives the liquid transfer member 121 of the cleaning device 101, i.e., when the electric shaver 103 is in the cleaning position shown in FIG. 2. In particular, FIG. 9 shows the measured current I in the sub-range PRMS within the range of the motor speed MS, as described above and as shown in FIG. 7. For the sake of simplicity, FIG. 9 shows only the first motor speed MS1, in this example approximately 5200 rpm, the Nth motor speed MSN, in this example approximately 7300 rpm, and any intermediate motor speed MSi (1 < i < N) from among a plurality of N different motor speeds MS1, MS2, ..., MSN within the range PMS of the motor speed in which the electric motor 129 of the electric shaver 103 is controlled to operate sequentially based on the first step 303 of the second embodiment of the method 301 described above.

[0061] Figure 9 also shows linear regression relationships, denoted as LRR1 and LRR2, between N different motor speeds MS1, MS2, ..., MSN and the currents IM1, IM2, ..., IMN2 in the electric motor 129 determined for the N different motor speeds MS1, MS2, ..., MSN, based on the third step 307 of Method 301 described above, for the first and second quantitative states QC1 and QC2 of the cleaning fluid 119 in the cleaning device 101. Figure 9 further shows the slopes (dI / dMS)1 and (dI / dMS)2 of the linear regression relationships LRR1 and LRR2 determined in the fourth step 309 of Method 301 described above for the first and second quantitative states QC1 and QC2. By measuring the current IM in the electric motor 129 at multiple different motor speeds MS, preferably three or more different motor speeds, the degree to which the current IM in the electric motor 129 changes based on the motor speed MS can be expressed very accurately by the parameter PdI / dMS used in the second embodiment of Method 301, i.e., the slope dI / dMS value of the linear regression relationship between the multiple different motor speeds MS and the current IM determined with respect to the multiple different motor speeds. As shown in Figure 9, the slope value (dI / dMS) 1 in the first quantitative state QC1 is significantly higher than the slope value (dI / dMS) 2 in the second quantitative state QC2. As a result, in the second embodiment of Method 301, the first quantitative state QC1 can be easily and robustly distinguished from the second quantitative state QC2 by determining whether the determined slope value dI / dMS is greater than or less than a second predetermined threshold PTH2, as described above. Those skilled in the art should note that an appropriate value for the second threshold PTH2 can be determined based on simple and easy experiments.

[0062] As is known to those skilled in the art, the coefficient of determination R2 or Pearson coefficient determined in step 311 of the fifth option of Method 301 described herein is a measure of the degree of variation in the measured relationship between current IM and motor speed MS, as shown in Figure 9. Relatively small values ​​of the coefficient of determination R2 usually correspond to a relatively large degree of variation in the relationship. Since a relatively large degree of variation in the relationship indicates that the flow of cleaning fluid 119 generated by the liquid transfer member 121 is unstable, a relatively small value of the coefficient of determination R2 indicates that the flow of cleaning fluid 119 is unstable, for example, alternating between stability and interruption. Accordingly, in the sixth option of Method 301, step 313, by determining whether the determined coefficient of determination R2 is below the predetermined third threshold PTH3, the third quantitative state QC3 of the cleaning fluid 119 in the cleaning apparatus 101 can be determined in relation to the transition state of the amount of cleaning fluid 119 from the first quantitative state QC1 to the second quantitative state QC2. Those skilled in the art can determine an appropriate value for the third threshold PTH3 based on simple and straightforward experiments. Note that in Figure 9, for simplification, the relationship between the measured current IM and the motor speed MS for the third quantitative state QC3 is not shown.

[0063] The inventors found that in the embodiment of the personal care system 100 shown in Figures 2-4, the flow of cleaning solution 11 passing through the hair cutting unit 107 provided by the liquid injection nozzle 153 in the receiving chamber 113 of the cleaning device 101 contributes significantly to a relatively large value of the gradient (dI / dMS) 1 of the cleaning solution 119 in the first quantitative state QC1, as shown in Figure 9. However, experiments have shown that in other embodiments of the cleaning device and personal care system, such as the embodiment of the cleaning device 1 shown in Figure 1, the difference between the gradient values ​​(dI / dMS) 1 and (dI / dMS) 2 for the first quantitative state QC1 and the second quantitative state QC2 is large enough to accurately and robustly distinguish at least the first quantitative state QC1 and the second quantitative state QC2 using the second embodiment of Method 301 according to the present invention.

[0064] Figures 10 and 11 show, as a function of time, the measured current IM in the electric motor 129 of the electric shaver 103 during the cleaning program CP of the cleaning device 101 in an embodiment of the personal care system 100 shown in Figure 2. The electric motor 129 drives the liquid transfer member 121 of the cleaning device 101 to execute the cleaning program CP. In both figures, the measured current IM is shown with respect to the first and second quantitative states QC1 and QC2 of the cleaning liquid 119 in the cleaning device 101. In the embodiment shown in Figures 10 and 11, the cleaning program CP has a plurality of consecutive cleaning phases 321-i separated by an interruption phase 323. In particular, in this embodiment, the cleaning program CP has seven cleaning phases 321-1, 321-2, ..., 321-7. In the first, second, and third cleaning phases 321-1, 321-2, and 321-3, the electric motor 129 is driven at a first predetermined motor speed, approximately 6400 rpm in this example, for predetermined times t1, t2, and t3, respectively. As shown in Figures 10 and 11, the time periods t1, t2, and t3 are different from each other, lasting from a few seconds to about 5 seconds, respectively. In the fourth, fifth, sixth, and seventh cleaning phases 321-4, 321-5, 321-6, and 321-7, the electric motor 129 is driven at a second predetermined motor speed, approximately 7300 rpm in this example, for predetermined times t4, t5, t6, and t7, respectively. As shown in Figures 10 and 11, the time periods t4, t5, t6, and t7 are different from each other, lasting from a few seconds to about 10 seconds, respectively. The interruption phase 323 between cleaning phases 321-i is a period during which the electric motor 129 is not driven, and each phase lasts for several seconds. It is clear that the cleaning program CP may include multiple different cleaning phases with different time durations and / or motor speeds than those described above.

[0065] In the embodiments shown in Figures 10 and 11, the quantitative state of the cleaning fluid 119 in the cleaning device 101 is determined in the measurement phase MP immediately after the cleaning program CP using the method according to the present invention. That is, after controlling the electric motor 129 based on the cleaning program CP as described above, the electric motor 129 is controlled to operate sequentially at at least two different motor speeds in the measurement phase MP in order to determine the quantitative state of the cleaning fluid 119 in the cleaning device 101.

[0066] In the embodiment shown in Figure 10, the quantitative state of the cleaning fluid 119 in the cleaning device 101 is determined in a manner that is a slight modification of the first embodiment of Method 201 described above with reference to Figures 6 and 7. Specifically, in the first phase 325-1 of the measurement phase MP, the electric motor 129 is controlled to operate at a second motor speed MS2, approximately 7300 rpm in this example, and the current IM2 in the motor 129 is measured. At time t=tc, the motor speed is changed from the second motor speed MS2 to the first motor speed MS1, approximately 5600 rpm in this example. Subsequently, in the second phase 325-2 of the measurement phase MP, the current IM1 in the electric motor 129 is measured. Then, based on the measured currents IM1 and IM2 at the first and second motor speeds MS1 and MS2, the quantitative state of the cleaning fluid 119 is determined and fed back to the user by steps 213, 215, and 217 of the sixth, seventh, and eighth steps of Method 201 described above.

[0067] In the embodiment shown in Figure 11, the quantitative state of the cleaning fluid 119 in the cleaning device 101 is determined in a manner that is a slight modification of the second embodiment of Method 301 described above with reference to Figures 8 and 9. That is, in the measurement phase MP, the electric motor 129 is controlled to change its motor speed progressively and linearly over a predetermined time period tMP from the second endpoint MSN of the motor speed range PMS, in this example about 7300 rpm, to the first endpoint MS1, based on a preferred embodiment of the first step 303 of Method 301 described above. During the progressive change of the motor speed MS, each time the motor speed MS reaches one of N different motor speeds MS1, MS2, ..., MSN, the currents IM1, IM2, ..., IMN in the motor 129 are measured and recorded, respectively. Subsequently, the quantitative state of the cleaning solution 119 is determined based on the measured currents II, IM2, ..., IMN for N different motor speeds MS1, MS2, ..., MSN, and is fed back to the user by the third, fourth, and seventh steps 307, 309, and 315 of the method 301 described above.

[0068] In the embodiments of Figures 10 and 11, the quantitative state of the cleaning fluid 119 in the cleaning device 101 is determined after the completion of the cleaning program CP, so that the shaving unit 105 of the electric shaver 103 is clean. As a result, the influence of any foreign matter present on or inside the shaving unit 105 on the measurement of the current IM in the electric motor 129 is limited as much as possible. Thus, the quantitative state of the cleaning fluid 119 in the cleaning device 101 can be determined with sufficient accuracy immediately after the cleaning program CP, i.e., without first removing the electric shaver 103 from the cleaning device 101. However, alternatively, the quantitative state of the cleaning fluid 119 can be measured during the cleaning program CP, preferably in the latter half of the cleaning program CP when most of the foreign matter has been removed from the shaving unit 105. In embodiments where the cleaning device has a motor that drives a liquid transfer member, such as cleaning device 1 in Figure 1, the quantitative state of the cleaning fluid can be determined if there is no personal care device in the receiving chamber of the cleaning device.

[0069] The aforementioned processors 61, 161 can be implemented in various ways using software and / or hardware to perform the various functions described above. The processors 61, 161 may have one or more microprocessors or digital signal processors (DSPs) that can be programmed using software or computer program code to perform the required functions and / or to control the elements of the processors 61, 161 to implement the required functions. The processors 61, 161 can be implemented as a combination of dedicated hardware for performing some functions (e.g., amplifiers, preamplifiers, analog-to-digital converters (ADCs) and / or digital-to-analog converters (DACs)) and processing components (e.g., one or more programmed microprocessors, controllers, DSPs and associated circuits) for performing other functions. Examples of circuits that may be employed in various embodiments of the present invention include, but are not limited to, conventional microprocessors, DSPs, application-specific integrated circuits (ASICs) and field-programmable gate arrays (FPGAs).

[0070] The present invention also relates to computer program products for carrying out the present invention, in particular to computer programs on or within a carrier. The computer program may be source code, object code, intermediate code of source and object code such as partially compiled forms, or any other form suitable for use in implementing the methods according to embodiments of the present invention. It should also be understood that such computer programs may have many different architectural designs. For example, program code that implements the functions of a method, apparatus or system according to the present invention may be subdivided into one or more subroutines. Many different ways of distributing the functions among these subroutines will be apparent to those skilled in the art. The subroutines may be stored together in a single executable file to form a self-contained computer program. Such an executable file may have computer-executable instructions, such as processor instructions and / or interpreter instructions (e.g., Java interpreter instructions). Alternatively, one or more or all of the subroutines may be stored in at least one external library file and linked statically or dynamically, for example at runtime, to the main program. The main computer program includes at least one call to at least one subroutine. Subroutines may also have function calls to one another. Embodiments relating to a computer program product have computer-executable instructions corresponding to at least one processing stage of the method defined herein. These instructions may be subdivided into subroutines and / or stored in one or more files that are statically or dynamically linked. Another embodiment relating to a computer program product has computer-executable instructions corresponding to at least one means of the system and / or product defined herein. These instructions may be subdivided into subroutines and / or stored in one or more files that are statically or dynamically linked.

[0071] The carrier of a computer program can be any entity or device capable of carrying the computer program. For example, the carrier may include data storage devices such as ROMs, which are CD-ROMs or semiconductor ROMs, or magnetic recording media, which are hard disks. Furthermore, the carrier may be a carrier capable of transmitting electrical signals or optical signals, which can be transmitted via electrical or optical cables, or wirelessly or by other means. If the computer program is embodied in such signals, the carrier may consist of such cables or other devices or means. Alternatively, the carrier may be an integrated circuit into which the computer program is embedded, which is configured to perform or used to perform the relevant method.

[0072] Modifications to the disclosed embodiments can be understood and implemented by those skilled in the art who practice the principles and techniques described herein, based on a review of the figures, disclosures, and appended claims. In the claims, the word “has” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude plurality. One processor or other unit can perform the functions of multiple items described in the claims. The mere fact that certain means are described in different dependent claims does not imply that combinations of these means cannot be used advantageously. Computer programs can be stored or distributed on suitable media such as optical storage media or solid-state media supplied together with or as part of other hardware, but they can also be distributed in other forms, such as via the Internet or other wired or wireless communication systems. Any reference numerals in the claims should not be construed as limiting the scope of the claims.

Claims

1. A computer implementation method for determining the quantitative state of a cleaning solution in a cleaning device for personal care devices, wherein the quantitative state is related to the amount of cleaning solution present in the cleaning device, and the method is The steps include receiving a sensor output from a sensor related to the current in the motor that drives the liquid transfer member of the cleaning apparatus, The steps include determining the current in the motor from the received sensor output, A step of determining the quantitative state based on the determined current in the motor and based on a predetermined relationship between the quantitative state and the current in the motor, A step of controlling the motor so that it operates sequentially at at least two different motor speeds, For each of the at least two different motor speeds, the step is to receive the sensor output, The steps include determining the current in the motor from the individual received sensor outputs for each of the at least two different motor speeds, A step of determining the value of a parameter related to the degree to which the current in the motor changes depending on the motor speed, based on the current in the motor determined for at least two different motor speeds, A computer implementation method comprising the step of determining the quantitative state of the cleaning solution based on the value of the determined parameter and based on a predetermined relationship between the quantitative state and the parameter.

2. The computer implementation method according to claim 1, further comprising the steps of providing a feedback signal to a feedback member related to the determined quantitative state of the cleaning liquid, and notifying the user of the cleaning device of the determined quantitative state.

3. The step of determining that the cleaning solution has a first quantitative state when the determined value of the parameter is greater than or equal to a predetermined threshold, The computer implementation method according to claim 1 or 2, further comprising the step of determining that the cleaning solution has a second quantitative state different from the first quantitative state when the determined value of the parameter is less than a predetermined threshold.

4. A step of controlling the motor so that it operates sequentially at a first motor speed and a second motor speed different from the first motor speed, The steps include receiving the sensor output relating to the first motor speed and the second motor speed, The process includes the step of determining the current in the motor relating to the first motor speed and the second motor speed from the individually received sensor outputs, The computer implementation method according to claim 3, wherein the parameter is the difference between the currents in the motor determined for the first motor speed and the second motor speed.

5. A step of controlling the motor so that it operates sequentially at multiple different motor speeds within a range of motor speeds, The steps include receiving the sensor output for each of the multiple different motor speeds, The process includes the step of determining the current in the motor from the individually received sensor output at each of the plurality of different motor speeds. The computer implementation method according to claim 3, wherein the parameter is the slope of a linear regression relationship between the plurality of different motor speeds and the current in the motor determined for each of the plurality of different motor speeds.

6. The steps include determining the coefficient of determination R2 related to the linear regression relationship, The computer implementation method according to claim 5, further comprising the step of determining that the cleaning solution has a third quantitative state different from the first and second quantitative states when the coefficient of determination is less than a predetermined threshold.

7. The computer implementation method according to claim 5 or 6, comprising the step of controlling the motor to gradually or linearly change the motor speed from a first endpoint to a second endpoint of the motor speed range over a predetermined time period.

8. A computer program that, when executed by a suitable computer or processor, causes the computer or processor to perform the method described in any one of claims 1 to 7.

9. A cleaning device for personal care devices, The casing and A receiving room, within which at least a portion of the personal care device to be cleaned is received at a cleaning position, A reservoir that holds the cleaning solution, A liquid transfer member for transferring the cleaning liquid from the reservoir to the receiving chamber in order to clean the part of the personal care device, A motor that drives the liquid transfer member, A sensor that measures the current in the motor and provides a sensor output related to the measured current in the motor, The system includes a processor, the processor controls the motor, receives sensor output from the sensor, and determines the quantitative state of the cleaning liquid in the cleaning device based on the sensor output, the quantitative state being related to the amount of cleaning liquid present in the cleaning device, A cleaning apparatus wherein the processor performs the method according to any one of claims 1 to 7 to determine the quantitative state of the cleaning solution in the cleaning apparatus.

10. A personal care system comprising a personal care device and a cleaning device for the personal care device, wherein the cleaning device is The casing and A receiving room, within which at least a portion of the personal care device to be cleaned is received at a cleaning position, A reservoir that holds the cleaning solution, A liquid transfer member for transferring the cleaning liquid from the reservoir to the receiving chamber in order to clean the part of the personal care device, It has a driven coupling member connected to the liquid transfer member, The personal care device is Motor and, A sensor that measures the current in the motor and provides a sensor output related to the measured current in the motor, A drive coupling member connected to the motor, The system includes a processor that controls the motor and receives sensor output from the sensor, The driven coupling member of the cleaning device and the driven coupling member of the personal care device are coupled to each other at the cleaning position of the part of the personal care device, and the liquid transfer member of the cleaning device is drivable by the motor of the personal care device. A personal care system wherein the processor of the personal care device performs the method according to any one of claims 1 to 7 to determine the quantitative state of the cleaning solution in the cleaning device, and the quantitative state is related to the amount of cleaning solution present in the cleaning device.

11. The aforementioned processor, Based on a predetermined cleaning program, the rotational speed of the motor is controlled as a function of time. A cleaning device according to claim 9, or a personal care system according to claim 10, wherein, after controlling the motor based on the predetermined cleaning program, the motor is controlled to operate sequentially at at least two different motor speeds in order to determine the quantitative state of the cleaning liquid.

12. The personal care device is an electric shaver comprising a main body and a shaving unit coupled to the main body, and the receiving chamber of the cleaning device receives the shaving unit of the electric shaver at the cleaning position within the cleaning chamber, as described in claim 9 or 11, or the personal care system as described in claim 10 or 11.

13. The shaving unit has at least one hair cutting unit, the hair cutting unit having an external cutting member having a hair introduction opening, and an internal cutting member covered by the external cutting member and having a cutting element movable relative to the external cutting member, The cleaning device according to claim 12, or the personal care system according to claim 12, wherein the cleaning device has at least one liquid spray nozzle in the receiving chamber for each hair cutting unit, and when the shaving unit is in the cleaning position, it provides a jet of cleaning solution that is directly propagated to the individual hair cutting unit through at least one hair introduction opening.

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