Method for controlling overpressure in oral care tool

Abstract

A method for controlling overpressure in a powered oral care implement having a treatment head with at least one functional element driven by a motor. The method includes: detecting a stimulus energizing the motor; setting a baseline current; and repeatedly executing an overvoltage detection control loop, the loop including: measuring an instantaneous current draw of the motor; adding the increment value to the baseline current or subtracting the decrement value from the baseline current, thereby generating a dynamically adjusted baseline current; determining whether the difference between the instantaneous current draw and the dynamically adjusted baseline current exceeds a threshold, thereby detecting the occurrence of an overvoltage; and taking a corrective action in response to the detected occurrence of the overvoltage.

Description

Technical Field

[0001] This disclosure relates to electric oral care tools, such as electric toothbrushes, having a pressure control system, and methods for controlling pressure in such tools. Background Technology

[0002] Personal care and grooming have become an integral part of the lifestyle for many consumers today. Modern personal care products, such as oral care tools, rely on electricity to achieve the good quality results consumers expect. These oral care appliances are technologically advanced, and the increasing use of electric toothbrushes reflects consumers' growing awareness of the benefits they offer, such as convenience, efficacy, and health benefits. Electric toothbrushes deliver superior brushing results compared to conventional manual toothbrushes.

[0003] Electric toothbrushes typically include a handle and a replaceable brush head. The handle houses a battery and an electric motor, and the replaceable brush head is removably attached to the handle. The brush head includes movable functional elements, such as bristle carriers, with cleaning elements, such as bristle tufts, located at their free ends. The motor in the handle controls the movement of the functional elements, thereby moving the cleaning elements. Such movement can include, for example, up-and-down movement, left-and-right movement, or movement in a circular motion pattern (i.e., oscillation, rotation). In some electric toothbrushes, the bristle head is designed to vibrate.

[0004] While electric toothbrushes offer excellent benefits, a common potential problem with them is excessive pressure. Overpressure typically occurs when users apply high levels of pressure (compared to what is typically applied with non-electric toothbrushes) while brushing. This excessive pressure can lead to poor cleaning because electric toothbrushes are not designed for high-pressure use during brushing. Additionally, applying excessive pressure over a prolonged period can damage the user's gums. Therefore, it is desirable to monitor and prevent users from applying excessive pressure to the toothbrush bristles, ensuring that the force applied during brushing remains below undesirable and potentially harmful levels.

[0005] Various pressure sensing devices are known to be used in electric (and manual) toothbrushes to determine and / or limit the pressure applied to the bristles during brushing. For example, as is generally understood in the art, the current consumption from the electric motor in a toothbrush varies proportionally to the amount of pressure applied to the brush head. Several prior art attempts to address the overpressure problem in electric toothbrushes are outlined below.

[0006] US 5,784,742 relates to an electric toothbrush with an adaptive load sensor. The toothbrush includes a brush head that vibrates due to a drive assembly. The load sensor monitors the current consumed by the drive assembly to determine the mechanical load exposed to the toothbrush. The load sensor assembly generates an adaptive threshold signal representing the instantaneous maximum pressure load. When the sensed load voltage exceeds the adaptive threshold signal, the load sensor assembly de-energizes the drive assembly and generates an alarm signal to warn the user that the toothbrush has been overloaded.

[0007] US 9,687,329 relates to an electric toothbrush including a brush head, a motor, and a controller. The controller utilizes a power module to drive the motor and senses the motor's current. When the sensed current exceeds a predetermined current threshold, the current drives the motor in a pulse-activated mode. The pulse-activated mode causes pulsating bristle tuft movement, which alerts the user to release brush pressure. The controller then disables the motor and warns the user if brush pressure remains.

[0008] US 10,561,480 B2 relates to a toothbrush including a control component that monitors the current consumption of a DC motor and adjusts the current applied to the motor based on the current consumption. When the applied force exceeds a threshold, the motor control can alert the user and / or adjust the motor operation accordingly. The threshold can be a change in current relative to a no-load current value or a normal load current value (e.g., a current increment). Therefore, the toothbrush tracks incremental changes caused by motor operation or no-load current consumption. It is assumed that the initial current consumption indicates no-load current consumption. When the initial load is greater than an acceptable no-load condition, a default or historical no-load condition is applied to initialize the reading. To track current consumption, a sensing module tracks the mechanical load experienced on the bristles by tracking the current applied to the motor. The current consumed by the motor is proportional to the load (e.g., the force required to move the bristles), and the current consumed by the motor increases as the load increases. When the pressure exceeds the threshold, the control component provides an output to the user, such as, for example, vibration of the brush handle, activation of one or more lights, shutting off the motor, producing a buzzing or other audible sound, or a snapping motion from the brush tip.

[0009] One challenge in overpressure detection in electric toothbrushes is setting an appropriate threshold for overpressure to occur. Current consumption can vary naturally depending on the specific brush head and its mechanical characteristics, including the friction between its mechanical components and the degree of wear on those components. Therefore, for each brushing event, an overpressure threshold needs to be dynamically set and adjusted, taking into account the various variations mentioned herein.

[0010] Therefore, this disclosure solves the overpressure problem in electric oral care tools (such as, for example, electric toothbrushes). This disclosure relates to an electric oral care tool with an overpressure detection system configured to monitor motor current consumption to detect overpressure events and automatically take remedial measures, while avoiding the shortcomings of prior art devices and systems. This disclosure also relates to a method for controlling overpressure in electric oral care tools. Summary of the Invention

[0011] This disclosure provides an oral care tool including a pressure control system that does not assume that the initial current consumption of the motor represents a no-load condition. Instead, the pressure control system described herein calculates a dynamically adjusted baseline current. This disclosure also provides a method for controlling overpressure in an electric oral care tool.

[0012] In one aspect, this disclosure provides an oral care tool, such as a toothbrush, which includes a handle containing a battery electrically connected to an electric motor having a motor shaft. The toothbrush has a motion transmitter operatively connected to the motor shaft. The toothbrush includes a processing head having at least one functional element operatively connected to the motion transmitter for being driven thereby. As is known in the art, the processing head can be constructed and configured to be attached to and detached from the handle.

[0013] The toothbrush also includes a pressure control system electrically connected to the motor. The pressure control system includes a controller (e.g., a microcontroller) configured to detect stimulation that energizes the motor, set a baseline current, and repeatedly execute an overvoltage detection control loop to detect the occurrence of overvoltage. To set the baseline current, the microcontroller may be configured to measure the current consumption of the motor and set the baseline current to the measured current consumption. Alternatively, to set the baseline current, the microcontroller may be configured to set the baseline current to a predetermined value. In one embodiment, the predetermined value may be from about 100 mA to about 600 mA.

[0014] The overpressure detection control loop includes: measuring the instantaneous current consumption of the motor; adding an increment to or subtracting a decrement from the baseline current to generate a dynamically adjusted (calculated) baseline current; determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a threshold, thereby detecting the occurrence of overpressure; and causing the oral care tool to take corrective action in response to the detected overpressure. In one embodiment, the microcontroller is configured to detect whether the overpressure has been eliminated. The overpressure detection control loop for detecting the occurrence of overpressure can be executed repeatedly every 1 millisecond to 1000 milliseconds, and more specifically every 5 milliseconds to 100 milliseconds. In an example embodiment, the overpressure detection control loop is executed once every 10 milliseconds.

[0015] It may be beneficial to keep the dynamically adjusted baseline current at the lower end of the motor current. Many electric toothbrush users tend to apply a continuous load during brushing. Although users can reduce pressure during brushing, this usually only occurs for relatively short periods. Therefore, the decrease in baseline current needs to occur much faster than the increase in baseline current, since low-load conditions are significantly shorter than high-load conditions. On the other hand, as long as a load is applied, the dynamically adjusted baseline current increases incrementally at a slower rate until the baseline current and motor current have approximately the same value.

[0016] Tests have shown that when the reduction of the dynamically regulated baseline current occurs too slowly, it can be difficult to achieve high accuracy in managing overvoltages. The rate of decrease of the dynamically regulated baseline current can range from about 0.66 mA / sec to about 6000 mA / sec. In one example embodiment, a rate of decrease of about 200 mA / sec (or faster) for the dynamically regulated baseline current has been found to be particularly advantageous. Conversely, the rate of increase of the dynamically regulated baseline current can range from about 0.03 mA / sec to about 600 mA / sec. In one example embodiment, the rate of increase of the dynamically regulated baseline current is about 10 mA / sec.

[0017] Similarly, it is believed that setting increment and decrement values ​​such that the latter is significantly greater than the former will benefit the purpose of the overvoltage detection control loop. The decrement value can be at least ten, twenty, or even thirty times the increment value. For example, the decrement value can be from about 0.66 mA to about 6 mA. In one example embodiment, the decrement value is about 2 mA. The increment value can be from about 0.03 mA to about 0.6 mA. In one example embodiment, the increment value is about 0.1 mA.

[0018] To determine whether the difference between instantaneous current consumption and dynamically adjusted baseline current exceeds a threshold, the microcontroller can be configured to add the threshold to the dynamically adjusted baseline current. The threshold may include a high-load threshold indicating the motor's load condition and a low-load threshold indicating the motor's low-load condition.

[0019] When the difference between the instantaneous current consumption and the dynamically adjusted baseline current is equal to or exceeds a high-load threshold, corrective measures may include configuring the motor such that at least one functional element moves at a second intensity different from the first intensity. Corrective measures may be selected from the group consisting of: slowing the motor, generating an optical signal, generating a tactile signal, generating an audio signal, and any combination thereof.

[0020] Slowing down the motor causes the brush head, which has cleaning elements on it, to move at a reduced frequency or amplitude (e.g., rotate or oscillate). In a vibrating toothbrush, the vibration intensity can be reduced. The microcontroller can be further configured to increase the motor speed back to its original speed in response to the detection that an overpressure has been eliminated. When no overpressure is detected, the microcontroller configures the motor to cause at least one functional element to move at a first (i.e., "normal") intensity, where no corrective action is taken.

[0021] To detect whether the overvoltage has been eliminated, the microcontroller can be configured to determine whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than a low load threshold. If the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than the low load threshold, the microcontroller configures the motor to move at least one functional element with a first intensity.

[0022] In one implementation, the microcontroller is configured to implement a stabilization phase (or step) in response to the detection of a stimulus that powers the motor. The stabilization phase allows the motor to reach its performance equilibrium. During the stabilization phase, the microcontroller delays the measurement of current consumption and the setting of a baseline current. The stabilization phase can last from about 500 milliseconds to about 5000 milliseconds, and more specifically from about 1000 milliseconds to about 3000 milliseconds. In one example implementation, the stabilization phase lasts about 2000 milliseconds. The stabilization phase also allows the user sufficient time to bring the toothbrush to the user's teeth and apply pressure to the toothbrush cleaning element before the cleaning element begins to move.

[0023] The current consumption when no pressure is applied to the cleaning element (“no-load” condition) can be measured to set an overvoltage threshold above a predetermined value of the no-load current. However, most users of electric toothbrushes naturally prefer to activate the toothbrush when it is already in their mouth and pressure is applied to the cleaning element. When a user activates the electric toothbrush outside their mouth, the rapid movement of the cleaning element (whether rotational oscillation or vibration) almost inevitably causes water and toothpaste splashing, which is highly undesirable for the user. Therefore, conventional methods relying on measurements of the no-load condition are considered unreliable because they provide unsatisfactory results when implemented with an electric toothbrush.

[0024] For at least these reasons, the pressure control system of the oral care tool disclosed herein does not assume that the initial current consumption of the motor represents a no-load condition. Instead, the algorithm implemented in the pressure control system of this disclosure calculates a dynamically adjusted baseline current and determines whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a high-load threshold, thereby detecting the occurrence of overpressure.

[0025] According to this disclosure, since the microcontroller does not measure current consumption during the steady-state phase, a baseline is not set based on no-load conditions when the user applies pressure to the cleaning element during the steady-state phase. Instead, the microcontroller sets a baseline under load conditions after the steady-state phase has ended and when the user has applied pressure to the toothbrush's cleaning element.

[0026] On the other hand, this disclosure provides a method for controlling overpressure in an electric oral care tool having a handle, a motor, and a processing head having at least one functional element driven by the motor. The method includes the steps of: detecting a stimulus energizing the motor; setting a baseline current; and repeatedly executing an overpressure detection control loop. The step of setting the baseline current can be achieved by measuring the current consumption of the motor and setting the baseline current to the measured current consumption. Alternatively, setting the baseline current can be achieved by setting the baseline current to a predetermined value (e.g., a value from about 100 mA to about 600 mA).

[0027] In one implementation, the overvoltage detection control loop is repeatedly executed every 1 millisecond to 1000 milliseconds, and more specifically every 5 milliseconds to 100 milliseconds. In an example implementation, the overvoltage detection control loop is repeatedly executed every 10 milliseconds. Optionally, a waiting period can be implemented between the end of one loop and the beginning of the next loop, depending on the desired frequency and duration.

[0028] The overvoltage detection control loop includes: measuring the instantaneous current consumption of the motor; adding the increment value to the baseline current or subtracting the decrement value from the baseline current to generate a dynamically adjusted baseline current; determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a threshold value to detect the occurrence of overvoltage; and taking corrective measures in response to the detected overvoltage occurrence.

[0029] The steps of adding the increment value to the baseline current or subtracting the decrement value from the baseline current include: adding the increment value to the baseline current when the instantaneous current is equal to or higher than the baseline current, or subtracting the decrement value from the baseline current when the instantaneous current is lower than the baseline current. In one embodiment, the decrement value is greater than the increment value. The decrement value can be at least ten times, twenty times, or even thirty times the increment value. In one example embodiment, the decrement value is about 2 mA. In one example embodiment, the increment value is about 0.1 mA.

[0030] The step of determining whether the difference between the instantaneous current consumption and the dynamically regulated baseline current exceeds a threshold includes adding the threshold to the dynamically regulated baseline current. The method may also include a step of determining whether the overvoltage event has been eliminated.

[0031] The method may also include a stabilization step implemented in response to the detection of a stimulus that powers the motor. The stabilization step, during which the measurement of the motor's current consumption to set a baseline current is delayed, may last from about 500 milliseconds to about 5000 milliseconds, and more specifically from about 500 milliseconds to about 5000 milliseconds. In one example implementation, the stabilization step lasts about 2000 milliseconds.

[0032] The step of causing the oral care tool to take corrective measures in response to the occurrence of detected overpressure includes causing the oral care tool to take corrective measures selected from the group consisting of: slowing down the motor, generating a light signal, generating a tactile signal, generating a sound signal, and any combination thereof. In one embodiment, the step of causing the oral care tool to take corrective measures in response to the occurrence of detected overpressure includes configuring the motor such that at least one functional element moves at a second intensity different from a first intensity. Moving at least one functional element at the second intensity may include slowing down the rotational speed of the motor. The method may further include the step of increasing the speed of the motor back to its original speed in response to the detection that the occurrence of overpressure has been eliminated.

[0033] The step of determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a threshold may include determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a high-load threshold indicating the load state of the motor. Detecting whether the overvoltage has been eliminated may include determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than a low-load threshold indicating a low-load state of the motor, in which case the motor is configured to cause at least one functional element to move at a first intensity. Attached Figure Description

[0034] The invention is described in more detail below with reference to various non-limiting embodiments and exemplary drawings, wherein: Figure 1 A schematic side view of an implementation of an oral care tool including an electric toothbrush.

[0035] Figure 2 for Figure 1 A schematic cross-sectional view of the electric toothbrush shown.

[0036] Figure 3 A flowchart illustrating the algorithm implemented in an implementation scheme of a pressure control system used in oral care tools. Detailed Implementation

[0037] In the context of this specification, the terms “processing force” or “processing pressure” (or simply “force” or “pressure”) are used interchangeably herein and refer to a force applied to the processing head in the processing direction. In electric toothbrushes, the processing direction is most typically a direction substantially perpendicular to the longitudinal axis of the toothbrush head. Although the total applied processing force (i.e., the force applied in more than one direction) may be greater than the processing force primarily applied in the processing direction, the components of processing force acting in directions other than the processing direction are neglected because those force components applied to the processing head in directions other than the processing direction are substantially absorbed in the bearings or through the elastic deformation of the oral care tool.

[0038] Figure 1 An embodiment of an oral care tool including an electric toothbrush 10 according to the present disclosure is illustrated. The toothbrush 10 includes a handle 110 and a toothbrush head 120 that is attached to and detachable from the handle 110. The handle 110 has a first end portion 111 and a second end portion 112 opposite to the first end portion 111, and a longitudinal axis 113 extending between the first end portion 111 and the second end portion 112 of the handle 110. Similarly, the toothbrush head 120 has a first end portion 121 and a second end portion 122 opposite to the first end portion 121, and a longitudinal axis 123 extending between the first end portion 121 and the second end portion 122 of the toothbrush head 120. When the toothbrush head 120 is attached to the handle 110, the first end portion 111 of the handle 110 and the first end portion 121 of the toothbrush head 120 are abutted against each other.

[0039] In some embodiments, when the toothbrush head 120 is attached to the toothbrush handle 110, the longitudinal axis 123 of the toothbrush head 120 may be substantially parallel to, and may even coincide with, the longitudinal axis 113 of the toothbrush handle 110. Figure 1 In other embodiments, when the toothbrush head 120 is attached to the toothbrush handle 110, the longitudinal axis 123 of the toothbrush head 120 and the longitudinal axis 113 of the toothbrush handle 110 may not be parallel to each other, and alternatively form an acute angle (not shown) between them.

[0040] The toothbrush head 120 has at least one cleaning element 125 disposed at a second end 122 of the toothbrush head 120. Figure 1 and Figure 2In the toothbrush head 120, there are multiple clusters 125, each cluster including multiple cleaning elements 126, such as bristles, which are attached to a cluster carrier 124, which is mounted for driven movement at a second 122 of the toothbrush head 120. During brushing, based on the design of the toothbrush 10, the cluster carrier 124 moves in a desired mode of movement, for example, in a mode including rotational oscillation, a mode including linear oscillation, a mode including pivoting oscillation, or any combination thereof. Toothbrushes constructed for various vibratory (non-rotational) movements are also known in the art. A power switch, such as, for example, an ON / OF button 160, may be conveniently located on the front surface 114 of the toothbrush handle 110.

[0041] As is known in the art, the toothbrush 10 can have multiple operating modes, each characterized by the frequency and / or amplitude of the movement (e.g., vibration, oscillation, rotation) of its functional elements (e.g., at least one cleaning element 125). Each mode can be designed to perform a certain function, such as daily brushing, gentle brushing, vigorous brushing, tongue cleaning, etc. The movement frequency of the at least one cleaning element 125 can be, for example, in the range of about 50 Hz to about 300 Hz.

[0042] Figure 2 A cross-sectional view of an embodiment of the toothbrush 10 is shown, wherein the handle 120 internally houses an electrical power source (such as, for example, a battery 130) and an electric motor (such as, for example, a direct current (DC) motor 140) electrically connected to the battery 130. A motion transmitter 150, disposed in both the toothbrush handle 110 and the toothbrush head 120 and including an output shaft 151, converts and transmits the continuous rotational movement of the motor into brushing movement of the cluster support 124 and the cleaning element 125. A controller (such as, for example, a microcontroller 170) is operatively communicated with the motor 140.

[0043] The microcontroller 170 may include a processor, such as one or more microprocessors, a controller, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and / or any suitable type of processor. The microcontroller 170 may also include memory (e.g., volatile memory, non-volatile memory) that stores machine-readable instructions corresponding to operations described, for example, with respect to a pressure control system, including implementing functionality described with respect to a steady-state phase and an overpressure detection control loop.

[0044] As previously described, brushing movements can be selected based on the specific design of the oral care tool, including the design of the motion transmitter 150. Figure 2In an example embodiment, an electric toothbrush 10 is illustrated, wherein a motion transmitter 150 includes a mechanism comprising, for example, a bevel gear (or helical gear) 152, thereby providing oscillating rotational movement of a cluster 125 including cleaning elements 126. However, other mechanisms and arrangements known in the art can be used to induce desired movement of the functional elements 124 of the tool. Similarly, known electric motors other than DC motors can be used to power the brush 10.

[0045] like Figure 3 As shown in Figure 300, the implementation scheme of the pressure control system operates according to an algorithm that begins when motor 140 is initially energized. Figure 3 (At 310). The microcontroller 170 first detects that the motor 140 is powered on, for example, by user activation of an ON / OFF switch (e.g., a button) 160. Figure 3 In the example implementation illustrated, the microcontroller 170 is configured to immediately implement a stabilization phase or step (at 304) after detecting that the motor 140 has been energized. During the stabilization phase, no measurement of the current consumption used to set the baseline current is performed, at least for reasons explained below.

[0046] Most users of electric toothbrushes generally prefer to activate the toothbrush when the functional element 124, with its cleaning element 126 (on which toothpaste is deposited), is already in the user's mouth. This avoids unwanted water and toothpaste splashing, which almost certainly occurs when the toothbrush is turned on and the functional element with toothpaste deposited on it begins to move outside the user's mouth. Users can begin brushing by applying low pressure and gradually increasing it to regular (habitual) brushing pressure. Alternatively, users can begin brushing by applying regular brushing pressure from the very beginning. These types of brushing behaviors are difficult to definitively define and define.

[0047] Simultaneously, the initial current consumption may be relatively high after the motor 140 is turned on. The mechanical system and electronics may require a short period to warm up and reach a steady state. Therefore, to avoid incorrect indications of excessive pressure based on relatively high initial current consumption, it may be advantageous to delay measurement during the duration of the steady-state phase. Thus, the microcontroller 170 can be configured such that it does not measure current consumption to set a baseline current during the steady-state phase. The steady-state phase can last from approximately 500 milliseconds to approximately 5000 milliseconds, more specifically from approximately 1000 milliseconds to approximately 3000 milliseconds. In one example embodiment, the steady-state phase lasts for approximately 2000 milliseconds.

[0048] Therefore, the stabilization phase is designed to allow the motor 140 to reach its full voltage and to allow the user sufficient time to bring the toothbrush 10 to the user's mouth, position the toothbrush cleaning element 126 against the teeth, and begin applying pressure to the cleaning element 126. This avoids setting the baseline current under no-load conditions. As previously explained, measuring the motor current under no-load (or "unloaded") conditions would be unreliable for calculating the overvoltage threshold. Instead, measuring the motor current while the user applies pressure to the toothbrush 10 inside the user's mouth provides a true setting and establishes a reliable basis for calculating the baseline current.

[0049] After the delay that occurred during the stabilization phase has ended, the microcontroller 170 measures the current consumption of the motor 140. Figure 3 At 306), and the baseline current is set to the initial current measurement result (at 308). Alternatively, the microcontroller 170 can be configured to set the baseline current to a predetermined value, for example, a value in the range of about 100mA to about 600mA.

[0050] After the baseline current has been set, the microcontroller 170 initializes the overvoltage detection control loop. When the user has applied pressure to the toothbrush head 120 (most commonly to avoid toothpaste splatter), the initial current / baseline may be relatively high. As the user moves the toothbrush 10 from the teeth to the teeth, the force on the brush head 120 may periodically decrease. Therefore, the measured current may also periodically decrease, and each time the current drops below a previous value, the baseline current is adjusted. This adjustment of the baseline current to lower and higher values ​​contributes to what is defined herein as a “dynamically regulated baseline current.”

[0051] During the overvoltage detection control loop, the microcontroller 170 first measures the instantaneous current consumption of the motor 140. Figure 3 At 310, the measured instantaneous current consumption is compared to the baseline current. When the instantaneous current is equal to or higher than the baseline current (high load condition of the motor) (at 312), the microcontroller 170 adds the increment value to the baseline current (at 316). On the other hand, when the instantaneous current is lower than the baseline current (low load condition of the motor), the microcontroller 170 subtracts the decrement value from the baseline current (at 316). By adding the increment value to the baseline current or subtracting the decrement value from the baseline current, the microcontroller 170 generates a dynamically adjusted baseline current, which will be used by the microcontroller 170 to detect the occurrence (or absence) of overvoltage.

[0052] As previously explained, the decrement value can typically be set greater than the increment value because the decrease in baseline current must occur faster than its increase, since low-load conditions are shorter than high-load conditions. The decrement value can be at least ten, twenty, or even thirty times the increment value. In one example implementation, the increment value can be about 0.1 mA. In another example implementation, the decrement value can be about 2 mA.

[0053] Then, to determine whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds the overvoltage threshold, the microcontroller adds the overvoltage threshold to the dynamically adjusted baseline current and compares the instantaneous current consumption with the sum of the dynamically adjusted baseline current and the overvoltage threshold. Figure 3 (At 318). When the instantaneous current consumption exceeds the sum of the dynamically adjusted baseline current and the overvoltage threshold, the microcontroller 170 sets an overvoltage detection flag to indicate that the motor 140 is operating under overvoltage conditions, and causes the toothbrush 10 to take corrective measures in response to the detected overvoltage (at 322, 324). In other words, the pressure control system determines that the motor 140 is under overvoltage conditions by detecting that the instantaneous current exceeds the dynamically adjusted baseline current by at least the overvoltage threshold. The corrective measures can be selected from the group consisting of: slowing down the motor speed, generating a light signal, generating a tactile signal, generating a sound signal, and any combination thereof.

[0054] If the instantaneous current consumption is lower than the sum of the dynamically adjusted baseline current and the overvoltage threshold, no overvoltage is detected, and the microcontroller: (a) takes no additional action and waits for the start of the next control loop, or (b) cancels the corrective action (e.g., increases the speed of motor 140 back to its original speed) in response to the detection that the overvoltage has been eliminated. Figure 3 (320 locations).

[0055] The frequency of executing the overvoltage detection control loop can be set to a single overvoltage detection control loop every 1 millisecond to 1000 milliseconds, more specifically every 5 milliseconds to 100 milliseconds, and even more specifically every 10 milliseconds. Depending on the desired frequency and duration of the overvoltage detection control loop, the microcontroller 170 can be configured to implement a wait period between two consecutive overvoltage detection control loops. Figure 3 (At position 326).

[0056] The overvoltage threshold includes a high-load (relatively high) threshold and a low-load (relatively low) threshold. The high-load threshold indicates a high-load state of motor 140, i.e., when motor 140 is in an overvoltage state. The high-load threshold can range from about 100 mA to about 500 mA, and more specifically from about 150 mA to about 300 mA, depending on the selected operating mode of toothbrush 10. In one example embodiment, the high-load threshold can be about 200 mA.

[0057] The low load threshold indicates a low load state of the motor, i.e., a state where a low load is applied to the motor 140 (e.g., when the motor 140 is no longer in an overvoltage state). To detect whether the overvoltage has been eliminated, the microcontroller 170 can be configured to determine whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than the low load threshold indicating the low load state of the motor. The low load threshold is lower than the high load threshold. The low load threshold can be about 20% to about 90% of the high load threshold. For example, the low load threshold can be about 50 mA to about 400 mA. In one example embodiment, the low load threshold is about 50% lower than the high load threshold.

[0058] In one implementation, when the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than a low-load threshold, the microcontroller 170 configures the motor 140 such that at least one functional element (i.e., cleaning element 126) moves at a first (low-load) intensity. Then, in the event of an overvoltage detection, corrective action may include configuring the motor 140 such that at least one functional element 126 moves at a second (high-load) intensity different from the first intensity. The second intensity may be lower than the first intensity. For example, the first intensity may include the normal speed of the motor 140, while the second intensity may include a reduced speed of the motor 140 relative to the normal speed. Naturally, the functional element 126 driven by the motor 140 with the reduced speed will move more slowly than when driven by the motor 140 with its normal / normal speed.

[0059] By increasing or decreasing the baseline current value at each control loop (i.e., by generating a dynamically adjusted baseline current), the pressure control system adjusts the overpressure threshold over time in a manner that takes into account changes in current consumption introduced by differences and / or wear and tear of the brush head 120, and does not depend on measurements of no-load current consumption.

[0060] Furthermore, as previously explained, the pressure control system performs a comparison with the overpressure threshold in each overpressure detection control loop ( Figure 3The baseline current is dynamically adjusted during the period (at points 312, 314, and 316). Therefore, even if the electric toothbrush 10 is activated in the no-load state of the motor 140, the dynamically adjusted baseline current value used in the comparison is not the measured no-load current consumption, but a modified version of the current with increments or decrements based on the comparison result of the instantaneous current and the baseline current.

[0061] In one implementation, the microcontroller 170 performs two comparisons to determine the presence or absence of overvoltage: a low-load comparison to detect the presence of an overvoltage condition, and a high-load comparison to detect that the overvoltage condition has been resolved. In the high-load comparison ( Figure 3 At 322, the microcontroller 170 compares the instantaneous current with the sum of the dynamically adjusted baseline current and the high load threshold to indicate a high load state of the motor 140. When the instantaneous current exceeds the sum of the dynamically adjusted baseline current and the high load threshold, the microcontroller 170 sets an overvoltage indicator flag to indicate that the motor 140 is operating under overvoltage conditions and reduces the speed of the motor 140.

[0062] In other words, the pressure control system determines that the motor 140 is in an overvoltage state by detecting that the instantaneous current exceeds the dynamically adjusted baseline current by at least the high load threshold. Conversely, when the instantaneous current is below the sum of the dynamically adjusted baseline current and the high load threshold, the microcontroller 170 does not take any additional action and waits for the start of the next overvoltage detection control loop.

[0063] In low-load comparison ( Figure 3 At point 318, microcontroller 170 compares the instantaneous current with the sum of the dynamically adjusted baseline current and the low-load threshold. When the instantaneous current is lower than the sum of the dynamically adjusted baseline current and the low-load threshold, microcontroller 170 sets the overvoltage indicator flag to false to instruct motor 140 to no longer operate under overvoltage conditions and sets the speed of motor 140 back to its original speed. Conversely, when the instantaneous current is greater than or equal to the sum of the dynamically adjusted baseline current and the low-load threshold, microcontroller 170 takes no additional action and waits for the start of the next overvoltage detection control loop.

[0064] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified herein, each such dimension is intended to represent both the stated value and a functionally equivalent range around that value. For example, a dimension disclosed as “40 mm” is intended to mean “approximately 40 mm” or “about 40 mm”. Furthermore, approximate terms such as “approximately” and “about” can be used to refer to numerical values ​​that may actually represent slightly different values ​​from the stated precise values. Thus, in the context of this disclosure, these terms can indicate the degree to which quantitative values, measurements, or other related representations may differ slightly from the stated precise values ​​without altering the essential function of the subject matter.

[0065] Unless expressly excluded or otherwise limited, the disclosure of every document cited herein, including any cross-references or related patents or patent applications, and any patent application or patent claiming priority to or benefiting from them, is incorporated herein by reference in its entirety. A reference to any document is not an admission that it is prior art concerning any invention disclosed or claimed herein, nor is it an admission that it, alone or in any combination with any other reference, teaches, suggests, or discloses any such invention. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in a document incorporated herein by reference, the meaning or definition given to that term in this invention shall prevail.

[0066] While specific embodiments of the invention have been illustrated and described by way of example, it will be apparent to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. For example, the accompanying drawings provided herein to illustrate exemplary embodiments should not be construed as limiting the invention, which is set forth in the claims herein. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered in the appended claims.

Claims

1. A method for controlling overpressure in an electric oral care tool, the electric oral care tool having a treatment head having at least one functional element driven by a motor, the method comprising the steps of: - Detect the stimulus that powers the motor; - Set the baseline current; as well as - Repeatedly execute the overvoltage detection control loop, which includes the following steps: ○ Measure the instantaneous current consumption of the motor; ○ The increment is added to the baseline current or the decrement is subtracted from the baseline current to generate a dynamically adjusted baseline current; ○ Determine whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a threshold, thereby detecting the occurrence of overvoltage; and ○ Corrective measures are taken in response to the occurrence of detected overvoltage.

2. The method of claim 1, wherein the step of setting the baseline current includes... - Measure the current consumption of the motor and set the baseline current as the measured current consumption, and / or - Set the baseline current to a predetermined value.

3. The method of claim 1 or claim 2, wherein the step of adding the increment value to the baseline current or subtracting the decrement value from the baseline current comprises: - When the instantaneous current is equal to or higher than the baseline current, the increment is added to the baseline current, or - When the instantaneous current is lower than the baseline current, the decrease value is subtracted from the baseline current.

4. The method according to any one of claims 1 to 3, wherein the step of determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds the threshold comprises adding the threshold to the dynamically adjusted baseline current.

5. The method of any one of claims 1 to 4, wherein the step of determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds the threshold comprises comparing the instantaneous current consumption with the sum of the dynamically adjusted baseline current and the threshold.

6. The method according to any one of claims 1 to 5, wherein the method includes the step of detecting whether the occurrence of overpressure has been eliminated.

7. The method according to any one of claims 1 to 6, wherein in the step of adding the increment value to the baseline current or subtracting the decrement value from the baseline current, the decrement value is greater than the increment value.

8. The method of claim 7, wherein the decrease value is at least ten times the increase value, and particularly wherein the decrease value is at least twenty times the increase value.

9. The method of any one of claims 1 to 8, wherein the method includes a stabilization step in response to detection of a stimulus energizing the motor, wherein during the stabilization step, a measurement of the current consumption is delayed to set the baseline current, wherein the stabilization step lasts from about 500 milliseconds to about 5000 milliseconds, and further particularly wherein the stabilization step lasts from about 2000 milliseconds.

10. The method according to any one of claims 1 to 9, wherein the overvoltage detection control loop is executed once every 1 millisecond to 500 milliseconds, particularly wherein the overvoltage detection control loop is executed once every 5 milliseconds to 20 milliseconds, and even more particularly wherein the overvoltage detection control loop is executed once every 10 milliseconds.

11. The method according to any one of claims 1 to 10, wherein in the step of performing corrective measures, the corrective measures are selected from the group consisting of: slowing down the speed of the motor, generating an optical signal, generating a tactile signal, generating an audio signal, and any combination thereof, particularly wherein in response to the detection that the occurrence of the overvoltage has been eliminated, the speed of the motor is increased back to its original speed.

12. The method according to any one of claims 1 to 11, wherein in the step of determining whether the difference between the instantaneous current consumption and the dynamically adjusted baseline current exceeds a threshold, the threshold includes a high-load threshold indicating a high-load state of the motor and a low-load threshold indicating a low-load state of the motor.

13. The method of claim 11 or claim 12, wherein the method includes the step of detecting whether the occurrence of the overvoltage has been eliminated, the step including determining that the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than the low load threshold, specifically including the step of: when determining that the difference between the instantaneous current consumption and the dynamically adjusted baseline current is less than the low load threshold, configuring the motor such that the at least one functional element moves at a first intensity, further wherein the corrective action includes configuring the motor such that the at least one functional element moves at a second intensity different from the first intensity.

14. The method of claim 12 or claim 13, wherein the high load threshold is about 100 mA to about 500 mA.

15. The method according to any one of claims 12 to 14, wherein the low load threshold is about 20% to about 90% of the high load threshold.

Images