Hair care appliance

Abstract

A hair care appliance is described comprising a body for engaging hair in use, a sensor arrangement and a control unit. The sensor arrangement is configured to output a plurality of signals, each signal indicating a presence of an object in a respective region of the body. The control unit is configured to determine whether the object is hair based on a time difference between the signals.

Description

Technical Field

[0001] The present invention relates to a hair care appliance. Background Art

[0002] Hair care appliances may include sensors for sensing the proximity of an object to the hair care appliance. However, sensors are typically unable to distinguish between hair and other objects. Summary of the invention

[0003] According to a first aspect of the invention there is provided a hair care appliance comprising: a body for engaging hair in use; a sensor arrangement configured to output a plurality of signals, each signal indicating the presence of an object at a respective region of the body; and a control unit configured to determine whether the object is hair based on a time difference between the signals.

[0004] This can reliably determine whether an object engaged with the body of the hair care appliance is hair. For example, hair detection based only on signals associated with a single area of ​​the body may tend to return false positives, i.e., tend to return a determination that hair is present, while in fact there is some other object, such as a table or a user's hand. Sensing the presence of an object independently at multiple areas of the body may not significantly improve this situation. However, by determining whether an object is hair based on the time difference between multiple signals, each of which indicates the presence of an object in a corresponding area of ​​the body, such false positives can be reduced or eliminated, i.e., it can be more reliably determined whether an object is hair. Specifically, rather than statically assessing whether an object is hair, using the time difference between the signals allows the dynamics of the contact of the object with the body to be incorporated into the determination. Since the dynamics of the engagement of hair with the body can be relatively specific, such as following a specific path and / or moving relative to the body at a specific rate or with specific other characteristics, the specificity and reliability of determining the presence of hair at the body can be correspondingly improved. Improving the reliability of determining whether an object engaged with the body of the hair care appliance is hair is an advantage in itself, but this can also in turn provide many other benefits, such as improved styling, improved energy efficiency, and improved product safety, as described in more detail below.

[0005] As described above, each signal indicates the presence of an object in a corresponding area of ​​the subject. In an example, each signal may be binary. For example, each signal may be logically low when the object is not present in the corresponding area, and each signal may be logically high when the object is present in the corresponding area. In other examples, each signal may be non-binary, such as having a range or continuous values. For example, the magnitude of the amplitude of each signal may indicate the proximity of the object to the corresponding area, or the extent to which the object appears in the corresponding area. In some examples, an object present in an area may correspond to an object in contact with the area. In other examples, an object present in an area may correspond to an object near or approaching the area.

[0006] In some examples, a first signal among the plurality of signals changes in response to an object present at a first area of ​​the subject; a second signal among the plurality of signals changes in response to an object present at a second area of ​​the subject; and the control unit is configured to determine whether the object is hair based on a time difference between changes in the first signal and the second signal.

[0007] It should be understood that in some examples, more than two signals may be used. For example, each of the multiple signals may change in response to an object being present at a corresponding area of ​​the body; and the control unit may be configured to determine whether the object is hair based on a time difference between changes in the multiple signals. For example, when an object is present in an area, the corresponding signal may increase in response. When using a hair care appliance, the dynamics of hair appearing in different areas of the body may be reliably distinguished from the dynamics of other objects. Therefore, basing the determination on the time difference between changes occurring in response to the object appearing in the corresponding area may allow for a reliable and / or robust determination of whether the object is hair.

[0008] In some examples, the control unit is configured to determine an order in which the objects appear in different corresponding areas of the body based on the changes in the signals, and the control unit is configured to determine whether the object is hair based on the determined order. For example, the order in which the objects appear in different respective areas can be inferred from the order in which the signals of the respective areas change. In some examples, the order may include the order in which the objects appear in different areas and / or the time between the objects appearing in different areas. Determining whether the object is hair based on the determined order can allow the way in which the hair engages with the body during use, in particular the movement of the hair relative to the body, to be incorporated into the determination. This can correspondingly improve the reliability of the determination.

[0009] In some examples, the control unit is configured to determine that the object is hair in response to the determined order corresponding to the predetermined order. For example, the predetermined order can be the order in which the hair is measured or observed when it is engaged with the body of the hair care appliance in use. In some examples, there can be multiple predetermined orders. Determining that the object is hair in response to the determined order corresponding to the predetermined order can allow, for example, one or more ways in which the hair is expected to engage or interact with the body when the hair care appliance is used to be incorporated into the determination. For example, if the object contacts the body in a manner that has been observed or expected when the body contacts the hair, the probability that the object is hair is relatively high, while if the object contacts the body in a manner different from that which has been observed or expected when the body contacts the hair, the probability that the object is hair is relatively low. This can reduce the probability of determining that the object is hair when the hair care appliance is not actually contacting the hair, and thereby improve the reliability of the hair presence determination.

[0010] In some examples, the body includes a curved portion, and the areas are distributed to follow the curve of the curved portion. Certain hair care appliances, such as styling rods, curling rods, and hairbrushes, may have a curved portion on or around which hair may be wrapped when in use. Hair may be formed from many relatively flexible strands and may therefore easily follow the curve of the curved portion when in use. Therefore, distributing the areas of the output signal to follow the curve of the curved portion may allow the winding motion of the hair along the curve to be encoded into the determination of whether the object is hair. Similar to the above, this may improve the reliability of the determination.

[0011] In some examples, the curved portion has the shape of a cylinder or cone, and the regions are distributed around the circumference of the cylinder or cone. This can allow the degree to which the object is wrapped around the body, or whether the object is completely wrapped, to be encoded into the determination of whether the object is hair. Similar to the above, this can improve the reliability of the determination.

[0012] In some examples, the sensor arrangement includes a plurality of sensors, each sensor being located in a corresponding area of ​​the body and being configured to output one of a plurality of signals. This can provide a robust way to provide a plurality of signals. For example, each sensor can output a signal independently of the other sensors. This can, for example, allow a clear and reliable signal about the presence of an object at each area. In addition, this can allow the determination of whether an object is hair to be transported to be robust with respect to a failure of one of the sensors. In some examples, one or more sensors are contactless sensors. For example, a contactless sensor can be configured to output a signal indicating that an object is present at the sensor without the object having to be in physical contact with the sensor itself. Examples of contactless sensors include capacitive sensors (e.g., self-capacitive sensors or mutual-capacitive sensors), optical sensors, and ultrasonic sensors. In some examples, one or more sensors can be contact sensors, i.e., sensors configured to output a signal indicating that an object is present at the sensor only when the object is in physical contact with the sensor itself. Examples of contact sensors include touch sensors, force sensors, and pressure sensors. Another example of a contact sensor is an element coupled to a temperature sensor configured to measure the temperature of the element, and whereby contact of an object with the element causes a change in the temperature of the element, and thereby a change in the signal output by the temperature sensor. Other types of sensors may be used.

[0013] The non-contact sensor allows determination of whether an object is hair even when the object is not physically contacting the sensor. However, hair care appliances that use non-contact sensors to detect the presence of hair, especially those hair care appliances whose sensors are positioned to sense free space, may be particularly prone to false positives because hair may be erroneously detected even when the subject is not contacting any object. Therefore, the present invention is particularly effective in improving the reliability of hair presence detection for hair care appliances using non-contact sensors.

[0014] In some examples, each signal comprises a time series of values, or the control unit samples each signal as a time series of values, and each value indicates the extent to which an object is present in a corresponding area at a given time. This can allow a microcontroller or other computer processor to easily perform the determination, which can provide a cheap, simple, flexible and / or low weight device by which to determine whether an object is hair. This is, for example, compared to using hard-wired circuit logic, although hard-wired circuit logic may also be used in some other examples.

[0015] In some examples, the control unit is configured to determine whether the object is hair based on a time difference between a plurality of signals occurring within a given time window. This may allow a determination of whether the object is hair to be made within a particular time period. This may allow, for example, the determination to be made periodically and / or repeatedly at successive times, which in turn may allow the determination to be reliably updated over time. Where each signal comprises or is sampled as a time series of values, the control unit may be configured to determine whether the object is hair based on the values ​​of the plurality of signals occurring within a given time window.

[0016] In some examples, the control unit is configured to: between successive determinations of whether an object is hair, shift a given time window so as to include the latest values ​​of the plurality of signals and remove the oldest values. This can allow determination of whether an object is hair to be made in an efficient manner. For example, by including only the latest values ​​of the plurality of signals, the control unit can continuously provide updated hair presence determinations relatively quickly, while consumption of processing and memory resources of the control unit can be kept at or below an appropriate level.

[0017] In some examples, the control unit is configured to use a trained machine learning model to determine whether the object is hair. For example, the trained machine learning model can be or include a regression model. In some examples, the machine learning model can be a trained neural network, although other trained machine learning models can also be used. In some examples, the control unit can be configured to: input multiple signals into the trained machine learning model to obtain an output, and determine whether the object is hair based on the output. For example, the trained machine learning model may have been trained to output a determination of whether the object is hair based on the input of multiple such signals. For example, the machine learning model can be trained based on a training data set including multiple training data samples, each training data sample including multiple such signals and a label indicating whether the object associated with the multiple signals is hair. In some examples, the training data set may include positive training data samples and negative training data samples, the positive training data samples including multiple such signals and a label indicating that the object associated with the multiple signals is hair, and the negative training data samples including multiple such signals and a label indicating that the object associated with the multiple signals is not hair.

[0018] Using a trained machine learning model can allow for reliable and / or flexible determination of whether an object is hair. For example, this can be compared to applying a hard-coded algorithm to multiple input signals to determine whether an object is hair. For example, such a hard-coded algorithm or rule set is inflexible to the timing of signal changes, which are not taken into account when the rules are written. However, a trained machine learning model can generalize from the training samples on which it has been trained, and is therefore more flexible relative to such untrained timing. As another example, using a hard-coded algorithm or rule set would require writing a rule set, which is not only labor-intensive, but may necessarily involve assumptions about the way hair interacts with the body of the hair care appliance, and may not take into account the precise way hair interacts with the body. On the other hand, using a machine learning model, which, for example, may have been trained using training data, the training data including actual signal values ​​when it is known that hair is engaged with the body (e.g., when hair is not engaged with the body, and / or when the body is engaged with an object other than hair (e.g., a hand)), can automatically encode the precise way in which hair actually interacts with the body during use, and thus can allow for a more reliable determination of whether an object is hair.

[0019] In some examples, the control unit is configured to concatenate the values ​​of each of the multiple signals included in a given time window to obtain an input to the machine learning model. This can allow the time series of data to be converted into a column vector, which in turn can allow the multiple signals in a given time window to be easily input into a machine learning model, such as a neural network having an input layer in this format.

[0020] In some examples, the control unit is configured to control the operating mode of the hair care appliance in response to the determination. This may allow the hair care appliance to operate more precisely with respect to whether hair is engaged with the body of the hair care appliance. For example, this may allow for improved styling or other functions, improved energy conservation, and / or improved product safety. For example, precisely controlling the hair care appliance to operate in a styling mode (e.g., which may include heating to a certain temperature and / or exhausting an airflow at a certain flow rate) when the hair is in contact with the body may allow for more precise styling of the hair. As another example, operating the appliance in an idle mode when it is determined that there is no hair, and operating the device in a styling mode when it is determined that the object is hair, may allow for reduced power consumption compared to the appliance in the styling mode, even when hair is not engaged. As another example, operating the appliance at a lower temperature when it is determined that the object is not hair, and operating the appliance at a higher temperature when it is determined that the object is hair, may allow for a reduced risk of a user accidentally burning themselves or other objects, such as when the appliance is not actively used to style hair. As another example, when it is determined that the object is not hair, the appliance is operated to exhaust or generate an airflow with a lower flow rate, and when it is determined that the object is hair, the appliance is operated to exhaust or generate an airflow with a higher flow rate, which can allow the risk of the user inadvertently directing the airflow toward an unintended object to be reduced.

[0021] In some examples, the control unit may include a controller configured to determine whether the object is hair and, in response, control an operation mode of the hair care appliance. In other examples, the control unit may include a first controller configured to determine whether the object is hair and a second controller configured to control an operation mode of the hair care appliance. In the latter case, the first controller may be configured to output a signal indicating a determination result of whether the object is hair to the second controller, for example.

[0022] In some examples, the hair care appliance exhausts an airflow, and the control unit is operable to control one or more of the flow rate and temperature of the airflow in response to the determination. Similar to as described above, this can allow for improved styling or other functions, improved energy efficiency, and / or improved product safety.

[0023] In some examples, the control unit is configured to: in response to determining that the object is not hair, operate the hair care appliance in a first mode; and in response to determining that the object is hair, operate the hair care appliance in a second mode, wherein the first mode of operation consumes less electrical power than the second mode of operation. Similar to what is mentioned above, this can allow for improved energy efficiency. Improving energy efficiency (e.g., reducing overall energy consumption) can be particularly important in battery-powered appliances because battery-powered appliances have limited energy storage capacity. As such, these features can allow for improved device runtime, and / or allow for the use of smaller batteries, which can reduce the weight of the appliance.

[0024] In some examples, the hair care appliance includes a heater, and the control unit is configured to operate the heater at a first temperature in a first mode, and to operate the heater at a second temperature in a second mode, the second temperature being higher than the first temperature. Similar to as described above, this can allow for improved styling or other functions, improved energy efficiency, and / or improved product safety.

[0025] In some examples, the hair care appliance includes an air inlet, an air outlet, and an air flow generator for generating an air flow from the air inlet to the air outlet, and the control unit is configured to operate the air flow generator at a first flow rate in a first mode and to operate the air flow generator at a second flow rate in a second mode, the second flow rate being greater than the first flow rate. Similar to as described above, this can allow for improved styling or other functions, improved energy efficiency, and / or improved product safety.

[0026] According to a second aspect of the invention, there is provided a control unit for a hair care appliance, the control unit being configured to: receive a plurality of signals, each signal indicating the presence of an object at a corresponding region of a body of the hair care appliance; and determine whether the object is hair based on a time difference between the signals. This may allow similar advantages as described above with respect to the first aspect. In some examples, the control unit may be the same as described above with reference to the first aspect. In some examples, the control unit may be located in a main part of the hair care appliance, such as a handle. In some examples, the signal may be received from an accessory, such as an accessory including a body, which may be attachable to and / or detachable from the body portion. This may increase the flexibility of the functionality of the hair care appliance. For example, the signal may be received wirelessly, or by a wire or conductive trace.

[0027] According to a third aspect of the invention, there is provided a method for determining whether hair is present on a body of a hair care appliance, the method comprising: receiving a plurality of signals, each signal indicating the presence of an object on a corresponding area of ​​the body; and determining whether the object is hair based on a time difference between the signals. This may allow similar advantages as described above in the first aspect. In some examples, the method may be performed by a control unit of the hair care appliance. In other examples, the method may be performed by a separate entity, for example, remote from the hair care appliance. For example, the signal may be sent to and received by a remote processor, and the determination may be made by the remote processor. In some examples, the result of the determination may be transmitted to and received by the hair care appliance, which in turn may control an operating mode, for example, based on the determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further features and advantages will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0029] Figure 1 is a schematic diagram showing a side view of a hair care appliance according to an example;

[0030] Figure 2 is a schematic diagram showing a perspective view of a main body of a hair care appliance according to an example;

[0031] Figure 3 is a schematic diagram illustrating engagement of hair with a body of a hair care appliance over time according to an example;

[0032] Figure 4 is a schematic diagram illustrating a graph of signal value outputs of a plurality of signals corresponding to respective plurality of regions of a body of a hair care appliance as a function of time according to an example;

[0033] Figure 5 is a schematic diagram showing a graph of signal values ​​as a function of element number of a column vector according to an example, the column vector may be used as an input to a machine learning model;

[0034] Figure 6a and 6b are schematic diagrams respectively showing a perspective view and a side view of a main body of a hair care appliance according to another example;

[0035] Figure 7 is a schematic diagram showing a control unit according to an example; and

[0036] Figure 8 is a schematic diagram illustrating a method of determining whether hair is present in a body of a hair care appliance according to an example.

[0037] As used herein, like reference numerals refer to like features. DETAILED DESCRIPTION

[0038] refer to Figure 1 , shows a hair care appliance 102 according to an example.

[0039] The hair care appliance 102 includes a body 104 for engaging hair during use (the hair is Figure 1 , but can be seen, for example, in the following description Figure 3 The body 104 includes a plurality of regions A, B, C. The hair care appliance 102 includes a sensor arrangement 128. The sensor arrangement 128 is configured to output a plurality of signals, each signal indicating the presence of an object at a respective region A, B, C of the body 104 (the object being Figure 1 Not shown, but see for example the following description Figure 3 The hair care appliance 102 includes a control unit 122. As described in more detail below, the control unit 122 is configured to determine whether the object 354 is hair based on the time difference between the signals.

[0040] In this example, the hair care appliance 102 includes a main portion 106, and a body 104 is provided as an accessory 104, which is attachable to and / or detachable from the main portion 106. The main portion 106 includes an airflow generator 124 and a heater 126. The airflow generator 124 is configured to generate an airflow from an air inlet 120 to an air outlet 123. In this example, the air inlet 120 is in the main portion 106, and the air outlet 123 is in the body 104. The heater 126 is located downstream of the airflow generator 124. The heater 126 can be configured to heat the airflow so as to provide a heated airflow at the air outlet 123. Figure 2 The body 104 of this example is shown in more detail in FIG. In this example, the body 104 is generally in the form of a cylinder or cone. In this example, each region A, B, C corresponds to an elongated member. In this example, these regions / members A, B, C are distributed around the periphery of the cylinder or cone forming the body 104 (see FIG. Figure 2213 in). In this example, the air outlet 123 is provided by the gap between each member A, B, C, which guides the airflow through the surface of the adjacent members A, B, C. It is known per se that in use, the airflow discharged from these air outlets 123 causes the hair near the body 104, or more specifically the hair bundle 354, to be wrapped around the body 104 by the Coanda effect, where it can be styled. In some examples, the control unit 122 can be configured to control the operating mode of the hair care appliance 102, such as controlling one or more of the flow rate and temperature of the airflow, such as controlling the flow rate of the airflow generated by the airflow generator 124 and / or controlling the operating temperature of the heater 126. In some examples, the control unit 122 can be configured to control the operating mode in response to the determination that the object 354 is hair. As explained in more detail below, this can allow improved styling, improved energy efficiency and / or improved product safety of the hair care appliance 102.

[0041] As described above, the hair care appliance 102 includes a sensor arrangement 128 configured to output a plurality of signals, each signal indicating the presence of an object at a respective region A, B, C of the body 104. In this example, the sensor arrangement 128 includes a plurality of sensors 114, 116, 118, each sensor 114, 116, 118 being located at a respective region A, B, C of the body 104 and configured to output one of the plurality of signals. In this example, each sensor 114, 116, 118 is positioned to sense radially outward from the body 104 (i.e., radially outward of the region A, B, C to which the sensor corresponds). In some examples, one or more of the sensors 114, 116, 118 may be a non-contact sensor. For example, the non-contact sensor may be configured to output a signal indicating the presence of an object 354 at the sensor 114, 116, 118 without the object 354 having to be in physical contact with the sensor 114, 116, 118 itself. Examples of non-contact sensors include capacitive sensors (e.g., self-capacitive sensors or mutual-capacitive sensors), optical sensors, and ultrasonic sensors. Non-contact sensors can allow determination of whether an object is hair even when the object is not physically in contact with the sensor. In other examples, one or more of sensors 114, 116, 118 can be contact sensors, i.e., sensors configured to output a signal indicating that object 354 is present at sensors 114, 116, 118 only when the object is in physical contact with the sensor itself. Examples of contact sensors include touch sensors (e.g., capacitive sensors or resistive sensors), force sensors, and pressure sensors. Another example of a contact sensor is an element coupled to a temperature sensor, the temperature sensor being configured to measure the temperature of the element, and whereby contact of the object with the element causes a change in the temperature of the element, and thereby causes a change in the signal output by the temperature sensor. Other types of sensors can be used. In some examples, one or more of sensors 114, 116, 118 can be any sensor whose output is affected by the presence of hair, which allows a high degree of flexibility in product integration. For example, where the area is heated, a high temperature resistant sensor (e.g., a heating element coupled to the above-mentioned temperature sensor) can be selected.

[0042] In some examples, each signal may be non-binary, such as having a range or continuous values. For example, the magnitude or amplitude of each signal may indicate the proximity of object 354 to the corresponding area A, B, C, or the extent to which object 354 exists in the corresponding area A, B, C. In other examples, each signal may be binary. For example, when object 354 is not present in the corresponding area A, B, C, each signal may be logically low, and when object 354 is present in the corresponding area A, B, C, each signal may be logically high. In some examples, object 354 present in area A, B, C may correspond to object 354 being close to or approaching area A, B, C. In other examples, object 354 present in area may correspond to object 354 being in contact with area A, B, C.

[0043] The sensor arrangement 128 may be connected to the control unit 122 by wire or wirelessly so as to provide a plurality of signals to the control unit 122. In an example where the body 104 is provided by an accessory and the control unit 122 is in the main part 106, the body 104 and the main part 106 may form a connection, which may be wired or wireless, through which signals may be transmitted from the sensor arrangement 128 to the control unit 122. In some examples, the sensor arrangement 128 may include sensors 114, 116, 118, and the signals output by each sensor may be directly provided to the control unit 122 as a plurality of signals. In other examples, the sensor arrangement 128 may include sensors 114, 116, 118 and a multi-channel reader (not shown), and the plurality of signals may be provided to the control unit 122 by the multi-channel reader (not shown). For example, the multi-channel reader may sample each signal output by the sensor as a time series of values, and provide the time series of values ​​as a plurality of signals to the control unit 122. In any case, the sensor arrangement 128 is configured to output a plurality of signals, each of which indicates the presence of an object in a corresponding area A, B, C of the body 104.

[0044] refer to Figure 3 and Figure 4 , Figure 3 It is shown that at different consecutive times T1, T2, T3, T4, the hair, or more specifically the hair bundle 354, can be around according to Figure 1 The manner in which the cylindrical body 104 of the exemplary hair care appliance 102 is wound; and Figure 4 1 shows a graph of a plurality of signals sA, sB, sC, sD, sE, sF output by the sensor arrangement 128 for a respective one of a plurality of regions A, B, C, D, E, F of the body 104 as a function of time according to an example. Note that regions D, E, F (and their associated sensors) exist at Figure 1 and 2On the main body 104 shown, but in Figure 1 and 2 Not visible in . Figure 3 and Figure 4 As can be seen in FIG. 1 , regions A to F are distributed on the periphery of the cylindrical body 104 in the order of A, B, C, D, E, and F. In this example, the greater the degree to which the object 454 exists in a given region among regions AF, the greater the signal sA-sF outputted corresponding to the given region AF.

[0045] At time T1, the hair bundle 354 is present in regions A and B, but not in regions C to F. Therefore, at time T1, the values ​​of signals sA and sB increase, but the values ​​of the other signals sC to sF do not increase. At a later time T2, the hair bundle 354 has further wrapped around the body 104, and now exists in regions A to C, but does not exist in regions D to F. Accordingly, at time T2, the values ​​of signals sA to sC have increased, but the values ​​of the other signals sD to sF have not increased. At a later time T3, the hair bundle 354 has further wrapped around the body, and now exists in regions A to D, but does not exist in regions E and F. Therefore, at time T3, the values ​​of signals sA to sD have increased, but the values ​​of the other signals sE to sF have not increased. At a later time T4, the hair bundle 354 has further wrapped around the body 104, and now exists in regions A to F. Accordingly, at time T4, the values ​​of signals sA to sF all increase.

[0046] As described above, the control unit 122 is configured to determine whether the object 354 is a hair based on the time difference between the signals sA-sF output by the sensor arrangement 128. The time difference can be considered as a difference between the signals occurring over a period of time, and can be contrasted with a purely static or instantaneous difference, for example. Figure 3 and 4As shown, each of the plurality of signals sA-sF may change (e.g., the value of the signal may increase) in response to the presence of the object 454 in the corresponding region A, B, C of the body. The control unit 122 may be configured to determine whether the object 454 is hair based on the time difference between these changes in the plurality of signals sA-sF. For example, the time difference between the two signals may include or be based on the time at which the change in one signal (e.g., the increase in the value of one signal) occurs relative to the change in the other signal (e.g., the increase in the value of the other signal). For example, the time difference between the signals may include the time difference at which each change occurs relative to the other changes (e.g., which may be expressed as the order or time sequence in which the signal changes occur), the time between each change, and / or other time-related differences. For example, based on the order in which the signal changes occur, the time between each change, and / or other time differences between the signals, the control unit 122 may determine whether the object 354 is hair. For example, when the time difference between the signals output by the sensor arrangement 128 corresponds to a known or expected time difference that occurs when hair contacts the body 104 (e.g., as Figure 3 ), the control unit 122 may determine that the object 354 is hair. For example, when the change in the signal corresponds to the change that would occur when the object surrounds the periphery 213 of the body, the control unit 122 may determine that the object is hair. Figure 4 In the schematic diagram of , the signals sA to sF are shown as increasing to similar values, but it should be understood that this is not necessarily the case and the signals may in principle increase by different amounts, but the control unit 122 may still determine whether the object is hair based on the time difference between the signals.

[0047] Using the time difference between the signals allows the dynamics of the engagement of the object 354 with the body 104 to be incorporated into the control unit 122's determination of whether the object 354 is hair. Because the dynamics of the engagement of the hair 354 with the body 104 can be relatively specific, such as following a specific path and / or moving relative to the body 104 at a specific rate or with specific other characteristics, the specificity and reliability of determining the presence of hair at the body 104 can be correspondingly improved. Improving the reliability of determining whether the object 354 engaged with the body of the hair care appliance is hair is an advantage in itself, but this can also in turn allow for providing a number of other benefits, such as improved styling, improved energy efficiency, and improved product safety, as described in more detail below.

[0048] As described above, in some examples, each of the plurality of signals sA-sF may change in response to the object 354 being present at the respective regions A, B, C of the body; and the control unit 122 may be configured to determine whether the object 354 is hair based on a time difference between changes in the plurality of signals. When the hair care appliance 102 is used, the dynamics of the hair 354 appearing at the different regions A, B, C of the body may be reliably distinguished from the dynamics of other objects. Thus, basing the determination on the time difference between changes in the signals occurring in response to the object being present at the respective regions A, B, C may allow for a reliable and / or robust determination of whether the object is hair.

[0049] In some examples, the control unit 122 is configured to determine the order in which the object 354 appears in different corresponding areas AF of the subject 104 based on the change in the signal, and the control unit 122 is configured to determine whether the object 354 is hair based on the determined order. For example, the order in which the object 354 appears in different respective areas can be inferred from the order in which the signal of the respective areas AF changes (e.g., increases). For example, the signal changes (e.g., increases) of the corresponding areas A, B, C, D can occur at times tA, tB, tC, tD, respectively, and for example, in the case of tD>tC>tB>tA, it can be inferred that the object 354 appears in the corresponding areas in the order of A, B, C, D. In addition, from the time difference between tA, tB, tC, tD, the time difference between the objects appearing in the areas A, B, C, D, respectively, can be inferred. In some examples, when the corresponding signals sA, sB, sC, sD increase above a threshold, the object can be determined to be present in a given area A, B, C, D.

[0050] In some examples, the order in which the object 354 appears in the different corresponding areas AF of the body 104 may include the order in which the object 354 appears in the different areas A, B, C, D and / or the time between the appearance of the object 354 in the different areas A, B, C, D. Determining whether the object is hair based on the determined order may allow the manner in which the hair engages with the body 104 during use, and in particular the movement of the hair 354 relative to the body 104, to be incorporated into the determination of whether the object is hair 354. This may accordingly increase the reliability of the determination.

[0051] In some examples, the control unit 122 is configured to determine that the object 354 is hair in response to the determined order corresponding to the predetermined order. For example, the predetermined order may be an order that has been measured or observed when the hair 354 engages the body 104 of the hair care appliance 102 in use. In some examples, there may be multiple predetermined orders. Determining that the object is hair in response to the determined order corresponding to the predetermined order may allow, for example, one or more ways in which hair is expected to engage or interact with the body 104 when the hair care appliance 102 is used to be incorporated into the determination of whether the object is hair. For example, if the object 354 engages the body 104 in a manner that has been observed or otherwise expected when the body 104 engages the hair 354, the likelihood that the object 354 is hair is relatively high, while if the object engages the body 104 in a manner different from that which has been observed or otherwise expected when the body 104 engages the hair 354, the likelihood that the object is hair is relatively low. This may reduce the likelihood of determining that the object is hair when the hair care appliance 102 is not actually in contact with the hair, and thus increase the reliability of the hair presence determination. For example, the predetermined sequence may include the order in which hair appears (and, for example, remains present) in different regions A, B, C and / or the time between the appearance of an object in different corresponding regions. Figure 1 , 2 , 4 and 5 examples of the body 104 can be A, B, C, D, E, F (or in fact B, C, D, E, F, A; C, D, E, F, A, B; D, E, F, A, B, C; E, F, A, B, C; F, A, B, C, D, E; or a portion of any of these sequences), which follows in a continuous order the path that hair is expected to follow when it is wrapped around the body 104. As another example, the predetermined time between the appearance of the object in different areas can be a condition such as tB occurs within a predetermined time range relative to tA, tC occurs within a predetermined time range relative to tB, etc.; or, for example, tA, tB and tC all occur within a certain time of each other.

[0052] In some examples, each signal includes a time series of values, or the control unit 122 may sample each signal as a time series of values, and each value indicates the extent to which the object 354 is present in the corresponding area AF at a given time. This may allow the determination of the control unit 122 to be easily performed by a microcontroller or other computer processor, which may provide an inexpensive, simple, flexible and / or low weight means by which to determine whether an object is hair. This is, for example, compared to using hard-wired circuit logic, although, as described below, hard-wired circuit logic may also be used in some other examples.

[0053] In some examples, the control unit 122 may be configured to determine whether the object 354 is hair by applying an algorithm to a plurality of signals. In some examples, the algorithm may be implemented by a computer program executed on a processor such as a microcontroller. In other examples, the algorithm may be implemented by a control logic circuit. In either case, an algorithmic logic may be applied to a plurality of signals to determine whether the object is hair based on the time difference between the signals. For example, signals associated with the respective regions A, B, C may be monitored, and changes (e.g., increases) in the signal values ​​may be observed at respective times tA, tB, tC. A logic may be applied, that is, if these changes occur in a particular time sequence or order (e.g., tA>tB>tC, or tC>tB>tC) and / or the time difference between time tA and tB, and / or tB and tC is within a particular range, then the object is determined to be hair, otherwise the object is determined to be not hair. Other algorithmic logic may be applied.

[0054] In some examples, control unit 122 may use other means to determine whether object 354 is hair based on the time difference between the signals. For example, a trained machine learning model may be used to determine whether object 354 is hair, such as by inputting multiple signals into a trained machine learning model that outputs a determination based on the input signals. For example, values ​​representing each of the multiple signals as a function of time may be input together into a machine learning model that may map these input values ​​to a determination of whether the object is hair using an inference function derived from its training.

[0055] In some examples, control unit 122 is configured to determine the number of Figure 4 Whether the object is hair may be determined based on the time difference between multiple signals appearing within a time window 456 of the control unit 122. This may allow the determination of whether the object is hair to be made within a specific time period. This may allow, for example, the determination to be made periodically and / or repeatedly at consecutive times, which in turn may allow the determination to be reliably updated over time. Where each signal comprises or is sampled as a time series of values, the control unit 122 may be configured to determine whether the object is hair based on the values ​​of the multiple signals appearing within a given time window 456. For example, the time window 456 may be on the order of 1 or 2 seconds, such as 1.5 seconds. Each signal may include or be sampled as a time series of values, wherein the time between each value in the sequence is 125 ms. In the example where the time window 456 is 1.5 seconds, the time window 456 will accordingly include signal values ​​of each of the multiple signals at 13 different times.

[0056] In some examples, control unit 122 is configured to, between successive determinations of whether object 354 is hair, shift a given time window 456 so as to include the latest values ​​of the plurality of signals and remove the oldest values. This may allow for determinations of whether object 354 is hair to be made in an efficient manner. For example, by including only the latest values ​​of the plurality of signals, the control unit may provide updated hair presence determinations in relatively rapid succession while processing and memory resource consumption by control unit 122 may be kept at or below an appropriate level. For example, every 125 ms, the oldest value of the signal is removed and the latest value of the signal is added. Between each successive determination, time window 456 may be shifted by 125 ms. Other example time windows and sampling rates may be used.

[0057] In an example where each signal includes or is sampled as a time series of values, and in an example where the control unit 122 is configured to use a trained machine learning model to determine whether the object 354 is hair, the control unit 122 may be configured to concatenate the values ​​of each signal (the values ​​of the time series) included in the multiple signals sA-sF in a given time window 456 with each other, thereby obtaining an input to the machine learning model. This may allow the time series of data to be converted into a column vector, which in turn may allow multiple signals in a given time window to be easily input into a machine learning model, such as a neural network having an input layer in this format.

[0058] For example, a column vector may be formed in which the first six entries or elements are the signal values ​​of each of the six signals sA-sF at the earliest sampling time included in the given time window 456, the next six entries are the signal values ​​of each of the six signals sA-sF at the second earliest sampling time included in the given time window 456, and so on, until the last six entries are the signal values ​​of each of the six signals sA-sF at the latest sampling time included in the given time window 456. In the case where the given time window 456 includes 13 sampling times, this will result in a column vector with 78 elements. Figure 5 , according to an example, a graph 560 illustrating the signal value of each element of the column vector as a function of the element number or position in the column vector is shown. It can be seen that these values ​​and their positions in the column vector encode the changes in the signals sA-sF that occur as a function of time within a given time window 456, and also encode the time differences between these signals. The conversion of multiple signals to this format can provide the multiple signals as ready input to a machine learning model, such as a neural network having an input layer in this format (e.g., a neural network having 78 nodes in its input layer).

[0059] In some examples, the machine learning model can be a trained neural network, although other trained machine learning models can also be used. In some examples, the trained machine learning model can be or include a regression model. In examples where the trained machine learning model includes a neural network, the neural network can include an input layer, one or more hidden layers, and an output layer. In some examples, the output layer can include a classifier that is configured to classify a given input as being associated with a case where the object is hair or as being associated with a case where the object is not hair. In some examples, the control unit 122 can be configured to input multiple signals into the trained machine learning model to obtain an output, and determine whether the object 354 is hair based on the output. For example, the input can be as described above with reference to Figure 5 The column vector format is described. The output can be a classification of a given input (e.g., output by a classifier), which indicates that the object is hair or does not indicate that the object is hair. Determining whether the object is hair can be based on the classification, for example, the determination can be used as a classification result.

[0060] The trained machine learning model may have been trained to output a determination of whether object 354 is hair based on an input of a plurality of such signals. For example, the machine learning model may be trained based on a training data set including a plurality of training data samples, each training data sample including a plurality of such signals (e.g., in a column vector format as described above) and a label indicating whether object 354 associated with the plurality of signals is hair. In some examples, the training data set may include positive training data samples including a plurality of such signals and a label 354 indicating that the object associated with the plurality of signals is hair, and negative training data samples including a plurality of such signals and a label indicating that the object associated with the plurality of signals is not hair (e.g., a hand or a table). Training may include optimizing a loss function between a determination output by the model and a label associated with each training data sample.

[0061] Using a trained machine learning model can allow for reliable and / or flexible determination of whether an object 354 is hair. For example, this can be compared to applying a hard-coded algorithm to multiple input signals to determine whether an object is hair. For example, such a hard-coded algorithm or rule set is inflexible to the timing of signal changes, which was not anticipated when the rules were written. However, a trained machine learning model can generalize from the training samples on which it has been trained and is therefore more flexible relative to such untrained timing. As another example, using a hard-coded algorithm or set of rules would require writing the set of rules, which is not only labor intensive, but may necessarily involve assumptions about the manner in which the hair 354 interacts with the body 104 of the hair care appliance, and may not take into account the precise manner in which the hair interacts with the body 104. On the other hand, using a trained machine learning model, which, for example, may have been trained using training data including actual signals when hair is known to be engaged with a subject (e.g., when hair is not engaged with a subject, and / or when a subject is engaged with an object other than hair (e.g., a hand)), can automatically encode the precise manner in which hair actually interacts with subject 104 during use, thereby allowing a more reliable determination of whether object 354 is hair.

[0062] Refer to above Figures 1 to 5 In the described example, the body 104 includes a curved portion, and the regions A, B, C are distributed to follow the curve 213 of the curved portion. Specifically, in this example, the body 104 has an overall shape of a cylinder, and the regions AF are distributed around the outer circumference 213 of the cylinder. As described above, in this example, when the hair care appliance 102 is used to style hair, the hair can be engaged on or around the body 104, for example, can be wrapped around the outer circumference 213 of the body 104 for styling. The hair can be formed of many relatively flexible hair strands, and thus can easily follow the curve 213 of the curved portion in use. Therefore, distributing the regions AF of the output signal to follow the curve 213 of the curved portion can allow the winding movement of the hair along the curve 213 to be encoded into the determination of whether the object 354 is hair. This can improve the reliability of determining whether the object is hair 354. In this example, the curved portion 213 has a cylindrical or conical shape, and the regions AF are distributed around the outer circumference 213 of the cylinder or cone. This may allow the degree to which object 354 is wrapped around body 104, or whether object 354 is completely wrapped, to be encoded into the determination of whether object 354 is hair. This may increase the reliability of the determination.

[0063] In some examples, the control unit 122 may be configured to control the operating mode of the hair care appliance 102 in response to determining whether the object 354 is hair. This may allow the hair care appliance 102 to operate more precisely with respect to whether hair is engaged with the body 104 of the hair care appliance 102. For example, this may allow for improved styling or other functions, improved energy conservation, and / or improved product safety. For example, when hair is engaged with the body 104, precisely controlling the hair care appliance 102 to operate in a styling mode (which may, for example, include heating the heater 126 to a specific temperature and / or generating airflow at a specific flow rate by the airflow generator 124) may allow for more precise styling of hair. As another example, operating the appliance 102 in an idle mode when it is not determined that the object is hair, and operating the appliance 102 in a styling mode when it is determined that the object is hair, may allow for reduced power consumption even when the appliance 102 is in a styling mode when hair is not engaged. As another example, operating the heater 126 at a lower temperature when it is determined that the object is not hair, and operating the heater 126 at a higher temperature when it is determined that the object is hair, can allow for a reduced risk of a user accidentally burning themselves or other objects, such as when the appliance is not actively being used to style hair. As another example, operating the airflow generator 124 to generate an airflow with a lower flow rate when it is determined that the object is not hair, and operating the airflow generator 124 to generate an airflow with a higher flow rate when it is determined that the object is hair, can allow for a reduced risk of a user accidentally directing the airflow toward an unintended object.

[0064] In some examples, the control unit 122 may include a controller configured to determine whether the object is hair and, in response, control an operating mode of the hair care appliance. In other examples, the control unit may include a first controller (not shown) configured to determine whether the object 354 is hair, and a second controller (not shown) configured to control an operating mode of the hair care appliance 102. In the latter case, the first controller (not shown) may be configured to output a control signal, for example, to the second controller (not shown), indicating a result of determining whether the object is hair.

[0065] As described above, the hair care appliance 102 discharges an airflow, and the control unit 122 may control one or more of the flow rate and temperature of the airflow in response to the determination. In some examples, the control unit 122 is configured to: operate the hair care appliance 102 in a first mode in response to determining that the object is not hair; and operate the hair care appliance 102 in a second mode in response to determining that the object is hair, wherein the first mode operation consumes less electrical power than the second mode operation. For example, the control unit 122 may be configured to operate the heater 126 at a first temperature in the first mode, and to operate the heater 126 at a second temperature in the second mode, the second temperature being higher than the first temperature. As another example, the control unit 122 may alternatively or additionally be configured to operate the airflow generator 124 at a first flow rate in the first mode, and to operate the airflow generator 124 at a second flow rate in the second mode, the second flow rate being greater than the first flow rate. Similar to what was mentioned above, this may allow for improved styling or other functions, improved energy efficiency, and / or improved product safety. Improving energy efficiency (e.g., reducing overall energy consumption) may be particularly important in battery-powered appliances because battery-powered appliances have limited energy storage capacity. As such, these features may allow for improved run time of the device, and / or allow for the use of smaller batteries, which may reduce the weight of the appliance.

[0066] Reference above Figures 1 to 5 In the described example, each region AF corresponds to a section or fin of the body 104, and accordingly there is one sensor 114, 116, 118 associated with each fin. However, it should be understood that this is not necessarily the case, and in some examples, each fin may include multiple (e.g., 2) regions (not shown), for each region, the sensor arrangement 128 may be configured to output a corresponding signal. Thus, in some examples, each fin may include multiple (e.g., 2) sensors (not shown). However, in a manner similar to that described above, the control unit 122 may determine whether the object is hair based on the time difference between the signals.

[0067] Refer to above Figures 1 to 5 In the examples described, the body 104 of the hair care appliance 102 is in the form of a cylinder or cone, and the regions are distributed around the periphery of the cylinder 213. However, it will be appreciated that this is not necessarily the case, and in other examples other forms of the body and other distributions of the body regions may be used. For example, with reference to Figure 6a and 6b , a body 604 according to another example is shown. Figure 6a and 6b The subject 604 can be used to replace the above reference Figures 1 to 5The subject 104 is described. It should be understood that in other examples, other subjects may be used instead of the examples shown.

[0068] Figure 6a and 6b The body 604 shown in FIG. 1 may have the same Figures 1 to 5 The main difference is that in this example the body 604 is a brush. The brush 604 includes a brushing area 622 containing bristles 633. Figure 6b As can be clearly seen in the figure (the bristles 633 are not shown in the figure), the brushing area 632 is divided into a plurality of areas A', B', C', D' and E'. The body 604 includes a sensor arrangement 628, which is configured to output a plurality of signals, each signal indicating the presence of an object at a corresponding area A'-E' of the body. Specifically, the sensor arrangement 628 includes five sensors 646, 644, 638, 650, 652, which are respectively located in areas A', B', C', D' and E'. The areas A'-E' are distributed in three adjacent columns on the brushing area 622, the leftmost column having areas A' and B' overlapping each other, the middle row having area C' located in the central portion of the brushing area 632, and the rightmost row having areas D' and E' overlapping each other. This distribution can allow for regions A'-E' to be located relative to each other across the brushing zone 632 from side to side (e.g., B' and D'; A' and E'); regions A'-E' to be located relative to each other across the brushing zone 632 from top to bottom of the brushing zone 632 (e.g., regions B' and A'; and D' and E'); and regions A'-E' to be located at a diagonal of the brushing zone 632 relative to each other (e.g., regions B', C', E'; and regions A', C', and D'). The brushing zone 632 is curved within a plane. Thus, some regions are distributed to follow the curve 605 of the body 604 (e.g., regions B' and D'). However, other regions are distributed to follow a non-curved portion of the body 604 (e.g., regions D' and E' relative to each other). The distribution of regions can allow, regardless of the direction in which the brush 604 moves relative to the hair in use, it can still be determined whether an object is hair based on the time difference between multiple signals. In other words, the area distribution may account for the different paths that hair may follow across the brushing area 632 when the brush 604 is used.

[0069] Similar to the above description, the control unit 122 can be configured to determine whether the object is hair based on the time difference between the signals (two or more) output by the sensor arrangement 628. In some examples, the control unit 128 can first determine which of the bodies 104, 604 is attached to the main part 106, and the determination of whether the object is hair can be additionally based on this determination. This can allow the control unit 122 to determine which algorithm, such as which trained machine learning model (e.g., a model trained based on training data collected from the cylinder 104, or a model trained based on training data collected from the brush body 604) to apply to multiple signals in order to determine whether the object is hair.

[0070] Refer to above Figure 1 6 , the body 104 , 604 may be attached to the body 106 of the hair care appliance, but it should be understood that this is not required and in some examples, the body 104 , 604 may be integral with the hair care appliance 102 .

[0071] Refer to above Figure 1 In the example described to FIG. 6 , the hair care appliance 102 includes a heater 126 and an airflow generator 124, but it should be understood that this is not necessary, and in some examples, the hair care appliance 102 may not include one or both of these. For example, in some examples, the hair care appliance may be a styling stick or a hair straightener or another hair care appliance that does not necessarily include an airflow generator. As another example, the hair care appliance may not necessarily include a heater or an airflow generator, but may, for example, include a body that distributes hair products or treatments or other media to the hair. In these examples, reliably determining whether an object is hair can allow the medium to be reliably distributed to the hair, which can improve styling performance, media use efficiency, and / or product safety.

[0072] Reference above Figures 1 to 5 In the described example, there are 6 areas AF, and in the example described above with reference to Figure 6, there are 5 areas A'-E', but it will be appreciated that this is not necessarily the case and in some examples any number of areas (i.e. 2 or more areas, i.e. multiple areas) may be used.

[0073] Refer to above Figure 1 In the examples described to Figure 6, at least some of the regions AF are distributed along the curve 213, 605 of the curved portion of the body 104, 604, but it will be appreciated that this is not necessarily the case and in other examples the regions may be distributed along a non-curved portion of the body, for example the regions may lie in a plane. For example, this may be the case where the body comprises a heating element of a hair straightener comprising a planar heating plate.

[0074] Reference above Figure 1 In the example described in FIG. 6 , an example is given of determining that the object 354 is hair based on the time difference between changes (particularly increases) in the plurality of signals. However, it should be understood that in some examples, the control unit 122 may determine that the hair 354 is no longer present at the body 104, 604 of the hair care appliance 102 or no longer engaged with the body 104, 604 of the hair care appliance 102 when it has been determined that the object 354 is hair. For example, this determination may be made when one or more or all of the plurality of signals indicate that the object is no longer present at the corresponding area of ​​the body 104, 604, for example, when one or more or all of the plurality of signals drops below a certain value or becomes logically low. In some examples, the control unit 122 may be configured to control the operating mode of the hair care appliance in response to a determination that the object determined to be hair is no longer present at the body 104, 604, for example, controlling the hair care appliance to be in or return to the first operating mode as described above. This may help to further improve the styling accuracy, energy efficiency and / or product safety of the hair care appliance.

[0075] Refer to above Figure 1 In the examples described in FIGS. 6 to 6, the control unit 122 is included in the hair care appliance 102, in particular, in the main part 106 of the hair care appliance 102, and the hair care appliance 102 also includes a sensor arrangement 128, 628 located in the attachment 104, 604 of the main part 106, but it should be understood that this is not required. For example, in some examples, the main body 104, 604, the sensor arrangement 128, 628, and the control unit 122 can be provided in the integrated hair care appliance 102. As another example, the main body 104, 604, the sensor arrangement 128, 628, and the control unit 122 can be provided in the attachment 104, 604 of the main part 106 of the hair care appliance 102. As another example, one of the sensor arrangement 128, 628 and the control unit 122 can be provided in the attachment 104, 604 of the main part 106, and the other of the sensor arrangement 128, 628 and the control unit 122 can be provided in the main part 106. It should be understood that other configurations can be used. Furthermore, it should be understood that in some examples, the control unit 122 can in principle be located anywhere and can be provided separately from other components of the hair care appliance 102. For example, a control unit 122 for the hair care appliance 102 can be provided, the control unit 122 being configured to: receive a plurality of signals sA-sF, each signal sA-sF indicating the presence of an object at a corresponding region of the body 104, 604 of the hair care appliance 102; and determine whether the object is hair based on a time difference between the signals. In some examples, the control unit 122 can be the same as described above with reference to Figure 16. In other examples, the control unit 122 may be remote from the hair care appliance 102. In these examples, the plurality of signals may be transmitted to and received by the control unit 122, for example, via a wireless connection with the sensor arrangement 128, 628, and / or the determination result of the control unit 122 may be transmitted to and received by the hair care appliance 102, for example, via a wireless connection, and the hair care appliance 102 may in turn control the operating mode, for example, based on the determination result.

[0076] refer to Figure 7 , shows a control unit 722 according to an example. The control unit 722 may have the same Figure 1 6. In this example, the control unit 722 includes an input interface 723, an output interface 725, a processor 727, and a memory 729. For example, the input interface 723 can receive a plurality of signals, each indicating that an object exists in a corresponding area of ​​the body of the hair care appliance, for example according to any of the above examples. These signals can be received from a sensor arrangement 728 configured to output a plurality of signals. These signals can be received by wire or wirelessly. The processor 727 can be configured to determine whether the object is hair based on the time difference between the signals, for example according to any of the above examples, in conjunction with the memory 729. For example, the memory 729 can store a computer program that, when executed by the processor 729, causes the processor to receive a plurality of signals and determine whether the object is hair based on the time difference between the signals, for example according to any of the above examples. The output interface 725 can be configured to output the determination result as needed, for example, to a separate controller (not shown) configured to control the operating mode of the hair care appliance. In other examples, the control unit 722 can be configured to control the operating mode of the appliance in response to the determination of whether the object is hair. In these examples, the output interface 725 can be configured to output control signals or instructions to components of the hair care appliance (e.g., the heater 724 and the airflow generator 726) to control the operating mode of the appliance (e.g., according to any of the above examples). These control signals can be transmitted by wire or wirelessly.

[0077] refer to Figure 8 , a method for determining whether hair is present on a body of a hair care appliance is shown. The method includes, at step 880, receiving a plurality of signals, each signal indicating the presence of an object in a corresponding area of ​​the body. For example, the plurality of signals may be based on the above reference Figures 1 to 7 The method includes, in step 882, determining whether the object is hair based on the time difference between the signals. For example, the determination can be made based on the above reference Figures 1 to 7For example, the method can be performed by the control unit 122, 722 according to the above reference Figures 1 to 7 In some examples, the method may include the following: Figures 1 to 7 Any functional steps described, such as those mentioned above Figures 1 to 7 The described example controls any functionality of the control units 122 , 722 .

[0078] While specific examples have been described, it should be understood that these are illustrative examples only and that various modifications may be made without departing from the scope of the present invention as defined by the claims.

Claims

1. A hair care device comprising: a body for engaging hair in use; a sensor arrangement configured to output a plurality of signals, each signal indicating the presence of an object in a respective region of the body; and A control unit is configured to determine whether the object is hair based on the time difference between the signals.

2. The hair care appliance according to claim 1, wherein: A first signal of the plurality of signals changes in response to the presence of an object at a first area of ​​the body; a second signal of the plurality of signals changes in response to the presence of an object at a second area of ​​the body; and The control unit is configured to determine whether the object is hair based on a time difference between changes in the first signal and the second signal.

3. The hair care appliance according to claim 1 or 2, wherein the control unit is configured to determine an order in which objects appear in different corresponding areas of the body based on the change of the signal, and wherein the control unit is configured to determine whether the object is hair based on the determined order.

4. The hair care appliance of claim 3, wherein the control unit is configured to determine that the objects are hair in response to the determined order corresponding to a predetermined order.

5. A hair care appliance according to any one of claims 1 to 4, wherein the body comprises a curved portion, and the regions are distributed so as to follow the curve of the curved portion.

6. The hair care appliance according to claim 5, wherein the curved portion has a shape of a cylinder or a cone, and the areas are distributed around the circumference of the cylinder or cone.

7. A hair care appliance according to any one of claims 1 to 6, wherein the sensor arrangement comprises a plurality of sensors, each sensor being located at a respective region of the body and configured to output one of the plurality of signals.

8. The hair care appliance of claim 7, wherein one or more of the sensors are non-contact sensors.

9. The hair care appliance according to any one of claims 1 to 8, wherein the control unit is configured to determine whether the object is hair based on a time difference between the plurality of signals occurring within a given time window.

10. The hair care appliance according to any one of claims 1 to 9, wherein each signal comprises a time series of values, or the control unit samples each signal as a time series of values, and each value indicates the extent to which the object exists in the corresponding area at a given time.

11. The hair care appliance of claim 10, wherein the control unit is configured to determine whether the object is hair based on values ​​of a plurality of signals within a given time window.

12. The hair care appliance of claim 11, wherein the control unit is configured to shift the given time window between successive determinations of whether the object is hair to include the most recent value of the plurality of signals and to remove the oldest value.

13. The hair care appliance according to any one of claims 1 to 12, wherein the control unit is configured to use a trained machine learning model to determine whether the object is hair.

14. A hair care appliance according to claim 13 when appended to claim 11, wherein the control unit is configured to: The values ​​of each of the multiple signals included in a given time window are concatenated with each other to obtain the input of the machine learning model.

15. The hair care appliance according to any one of claims 1 to 14, wherein the control unit is configured to control an operation mode of the hair care appliance in response to the determination.

16. The hair care appliance of claim 15, wherein the hair care appliance discharges an air flow, and the control unit is operable to control one or more of a flow rate and a temperature of the air flow in response to the determination.

17. The hair care appliance according to claim 15 or 16, wherein the control unit is configured to: In response to determining that the object is not hair, operating the hair care appliance in a first mode; and In response to determining that the object is hair, the hair care appliance is operated in a second mode, wherein the first mode of operation consumes less electrical power than the second mode of operation.

18. The hair care appliance of claim 17, wherein the hair care appliance comprises a heater, and the control unit is configured to operate the heater at a first temperature in the first mode and to operate the heater at a second temperature in the second mode, the second temperature being higher than the first temperature.

19. The hair care appliance according to claim 17 or 18, wherein the hair care appliance comprises an air inlet, an air outlet and an air flow generator for generating an air flow from the air inlet to the air outlet, and the control unit is configured to operate the air flow generator at a first flow rate in the first mode and to operate the air flow generator at a second flow rate in the second mode, the second flow rate being greater than the first flow rate.

20. A control unit for a hair care appliance, the control unit being configured to: receiving a plurality of signals, each signal indicating the presence of an object in a corresponding area of ​​the body of the hair care appliance; and Whether the object is hair is determined based on the time difference between the signals.

21. A method of determining whether hair is present in a body of a hair care appliance, the method comprising: receiving a plurality of signals, each signal indicating the presence of an object in a corresponding region of the body; and Whether the object is hair is determined based on the time difference between the signals.

Images