Apparatus and method for styling hair

Abstract

The present disclosure relates to an apparatus for styling hair, the apparatus comprising: a heating device for heating hair; at least one sensor located on the housing of the device for determining the hair temperature while performing the styling process; and a controller configured to control the apparatus to take at least one action for controlling the shaping process based on an output of the at least one sensor. In one example, the apparatus comprises: a heater element for heating hair; comprising one or more temperature sensors; and a region disposed between the heater element and the sensing portion, the region being arranged to limit propagation of heat from the heater element toward the sensing portion.

Description

Technical Field

[0001] The present invention relates to devices and methods for styling hair, for example after washing the hair or as part of a styling process. Such hair styling may be performed by a user, for example on their own hair, or by a hair stylist. The invention particularly, but not exclusively, relates to a hair styling device having one or more sensors for measuring hair temperature, hair position, hair strand size and / or other properties relevant to the use of the hair styling device.

[0002] The present invention can be used to style dry hair. Alternatively, the hair can be wet (or "towel dried") prior to use of the present invention and can then be dried and / or styled using the present invention. It should also be noted that the term "wet" as used herein should be interpreted broadly to include not only hair that is wet with water, but also hair that is wet with liquids other than water. For example, hair can be wet with a solvent-based colorant that can be used to dry and / or style the present invention. Background Art

[0003] Heated hair styling tools use heat to raise the temperature of the hair to a desired styling temperature. For example, a hair straightener with a heater plate applies heat directly via conduction to heat the hair, which may be wet or dry, to achieve the desired temperature for styling. The hair may be heated to a temperature particularly suitable for styling the hair (e.g., heated to or above the glass transition temperature). At lower temperatures, the user may have to make multiple passes over the hair with a hair straightener or curling iron to achieve the desired styling effect, while at higher temperatures, there is a risk of permanent damage to the hair.

[0004] Similarly, a heating brush or a hair dryer can also be used to style the hair by heating the hair to a temperature suitable for styling. After being heated by the heating brush or the hot air from the hair dryer, a so-called "cool shot" of cold air can be used to set the hairstyle in place.

[0005] The desired curl compression (e.g., tight curl, loose curl, straight hair) can be achieved depending on many factors, including, but not limited to: the type of device used, the moisture level of the hair (e.g., before / after styling); the temperature used for styling; the ambient temperature, the amount of time the hair is exposed to heat; and the cooling rate of the hair after styling.

[0006] However, regardless of the type of hair styling device and the technique used to style the hair, it may be difficult for the user to achieve the desired look. For example, it may be difficult to achieve uniform curl compression or straight hair, especially for an inexperienced user. The risk of hair damage may also increase when the user needs to make multiple attempts to use the hair styling device to achieve the desired hairstyle. Therefore, there is a need for an improved hair styling device to help improve the user experience and allow the desired hair styling effect to be easily achieved.

[0007] The object of the present invention is to solve or at least partially improve one or more of the above problems. Summary of the invention

[0008] The present invention provides an apparatus for drying or styling hair and a method for drying or styling hair as described in the accompanying claims.

[0009] The present invention provides a device for styling hair, the device comprising: a handle portion for holding the device; a styling portion for styling hair; a heating device for heating the hair styled by the styling portion; at least one sensor located on the housing of the device for determining a temperature or position associated with the hair while performing a styling process; and a controller configured to control the device to take at least one action related to the output of at least one sensor. The at least one action may be storing the output for subsequent processing for hair diagnostic purposes, for user educational information, etc. The subsequent processing may be performed on the device or on a remote device such as a remote server or a user's mobile phone. Alternatively, at least one action may be processing the output from at least one sensor during the styling process to provide feedback to the user during styling; or

[0010] If the hair is not heated enough to produce the desired style, the heater is controlled to increase the heat, or if the hair is overheated and damaged, the heater is controlled to reduce the heat.

[0011] At least one action may also or alternatively include one or more actions selected from the following group: adjusting the power supplied to the heating device (for example, to ensure that the hair is not damaged); determining the type of styling process (for example, a straightening or curling process); determining the amount of hair to be heated (for example, the size of a lock of hair styled by the device); determining the type of hair being heated; determining the angle or curvature at which the hair is removed from the housing while performing the styling process (which indicates the amount of curl imparted to the hair); determining whether the styling process has achieved a particular style; predicting the user's satisfaction with the styling process; storing output from at least one sensor for subsequent processing; storing output to adjust future performance; storing output to calculate the user's ability; sending output from at least one sensor to a remote device; and / or outputting feedback related to the styling process to a user of the device (which may include instructions on how to use the device to achieve a desired hairstyle or instructions on using different control settings of the device, etc.).

[0012] The controller may be configured to control the styling process based on the output of the at least one sensor to obtain a curl compression level for the hair within a threshold range of the target curl compression level.

[0013] At least one sensor may be located on the edge of the surface heated by the heating device. A plurality of sensors may be arranged on the handle portion and / or the styling portion. In the case where at least one sensor is arranged on the handle portion of the device, at least one action may include determining the grip or orientation of the device.

[0014] According to another aspect, the present invention provides an apparatus for styling hair, the apparatus comprising: a handle portion for holding the apparatus; a styling portion for styling hair; at least one sensor mounted on the handle portion for determining information about how a user holds the device during a hair styling operation; and a controller configured to control the apparatus to take at least one action based on the determined information.

[0015] At least one action may be storing the determined information for subsequent processing for hair diagnostic purposes, for user educational information, etc. The subsequent processing may be performed on the device or on a remote device such as a remote server or a user's mobile phone. Alternatively, at least one action may be processing the determined information during the styling process to provide feedback to the user during styling; or controlling the heater to increase heating if the hair is not heated enough to produce the desired hairstyle, or controlling the heater to reduce heating if the hair is overheated and damaged. The determined information may be used to predict the type of styling the user is attempting to achieve or the user's ability to use the device, and the controller may control the operation of the device based on the predicted style or the user's ability.

[0016] The at least one sensor may comprise a continuous sensor arranged along the width or length of the handle portion and / or the styling portion, or may comprise a plurality of sensors arranged on the styling portion and / or on the handle portion.

[0017] At least one sensor may include one or more selected from the following group: a thermistor, a negative temperature coefficient (NTC) sensor, a thermocouple, an infrared radiation sensor, a pressure sensor, a force sensor, a proximity sensor, an optical sensor, a light sensor, a humidity sensor, an integrated ohmmeter, an accelerometer, a gyroscope, a magnetometer, and an anemometer.

[0018] The device may include a memory configured to store a plurality of operating parameters of the device for controlling a styling process; and the device may be configured to identify an operating parameter to be used from the stored plurality of operating parameters based on the output of the sensor. The operating parameter may include at least one of an operating temperature or power or heat output.

[0019] The device may also include means for generating an indication to a user whether a desired hair styling result has been achieved based on the output of the at least one sensor. The indication includes at least one of a visual indication, an audible indication, and a tactile indication.

[0020] The at least one sensor may be mounted on a circuit board within the housing or may be embedded within the housing.

[0021] In some embodiments, the housing is deformable and the sensor is a force sensor configured to sense deformation of the housing.

[0022] According to another aspect, the present invention provides a device for styling hair, the device comprising: a heating component for heating hair in contact with the heating component, the heating component comprising a heating portion and a sensing portion; a heater for heating the heating portion of the heating component; at least one temperature sensor mounted on the sensing portion; and wherein the heating component comprises a thermal restriction portion between the heating portion and the sensing portion, the thermal restriction portion restricting the propagation of heat from the heating device toward the sensing portion.

[0023] The thermally restrictive portion may provide a thermal bottleneck for heat flow from the heater to the sensing portion.

[0024] The thermally restrictive portion may include a gap, slot or groove between the heating portion and the sensing portion. The gap, slot or groove may be at least partially filled with a thermally insulating material.

[0025] The heating component may include a heater plate having a heater surface that heats hair in contact with the heater surface.

[0026] The sensing portion is typically positioned along an edge or peripheral portion of the heating element, and at least one temperature sensor is configured to measure the temperature of the hair as it moves from the heating portion to the sensing portion.

[0027] The device may include a plurality of bristles, and the heating component includes at least one of the bristles. The sensing portion may be located on or at the base of one or more of the plurality of bristles. The at least one temperature sensor may be configured to measure the temperature of the hair as the hair moves from the heating portion to the sensing portion. The at least one temperature sensor may include at least one of a thermistor, a negative temperature coefficient (NTC) sensor, a thermocouple, a resistive track or wire, an infrared radiation sensor, and an optical sensor.

[0028] The device can be a hair straightener, a hair curler, a hair dryer, a hot paddle brush, a hot round brush, a heater roller, or a combination thereof.

[0029] The at least one sensor may be a point sensor or a continuous sensor extending along the length of the sensing portion.

[0030] The present invention also provides a device for styling hair, the device comprising: a handle portion for holding the device; a styling portion for styling hair, the styling portion comprising a heating component and a plurality of bristles, the heating component being used to heat hair in contact with the heating component, the plurality of bristles being used to apply tension to the hair, wherein at least one of the bristles is a sensor bristle for sensing the temperature of the hair; and a controller configured to control the device to take at least one action based on the sensed hair temperature.

[0031] At least one sensor bristle may include a temperature sensor mounted on the sensor bristle or at the base of the sensor bristle.

[0032] One or more of the bristles may be heating bristles thermally coupled to a heating component. At least one sensor bristle may be a heating bristle thermally coupled to a heating component.

[0033] The controller may be configured to control the heat output of the heater of the heating element according to the sensed hair temperature. This may help to avoid damage to the hair.

[0034] The invention also provides a corresponding method. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0036] Figure 1a shows an overview of an exemplary hair styling device;

[0037] Figure 1b The hair styling device is shown in use;

[0038] Figure 2a shows an overview of a second exemplary hair styling appliance;

[0039] Figure 2b showing a second hair styling device in use;

[0040] Figure 3 Shows Figure 1a or Figure 2a A simplified block diagram of the main electrical and electronic components of the hair styling device shown in;

[0041] Figure 4a to Figure 4g Schematically illustrates an exemplary manner in which a sensor mounted around the housing of a molding device may be used;

[0042] Figure 5a and Figure 5b shows the manner in which a thermal bottleneck can be used to allow a temperature sensor to be mounted on a heater plate of a hair styling appliance;

[0043] Figure 6a and Figure 6b shows how filler material can be used to fill gaps in heater plates that form a temperature bottleneck;

[0044] Figure 7a and Figure 7b shows different sensors that can be mounted on the heater plate;

[0045] Figure 8a , Figure 8b and Figure 8c shows a hair styling device having six spot temperature sensors mounted on each heater plate of the device;

[0046] Figure 9a , Figure 9b and Fig.9c shows a hair styling device having two distributed temperature sensors mounted on each heater plate of the device;

[0047] Fig.10a and Fig.10b shows the manner in which a wire-based temperature sensor may be mounted on a heater plate of a hair styling appliance;

[0048] Fig.11a and Fig.11b shows the manner in which a thick film or printed temperature sensor track may be formed on the inner surface of a heater board;

[0049] Fig.12shows the manner in which a thick film or printed temperature sensor track may be formed on the outer surface of a heater board;

[0050] Fig. 13 shows the manner in which protrusions on the heater carrier may be received in slots in the heater plate to provide a smooth hair contacting surface on the upper (hair contacting) surface of the heater plate;

[0051] Figures 14a to 14c shows an exemplary manner of forming a thermal bottleneck in a heater plate by means of shaped slots and a filler shaped to fill the slots in the heater plate;

[0052] Figures 15a to 15d Schematically illustrates an exemplary manner in which the present invention may be implemented using a curling iron device;

[0053] Figures 16a to 16c Schematically illustrates an exemplary manner in which the present invention may be implemented using a brush-type hair styling device;

[0054] Fig.17a and Fig.17b shows the manner in which a thermal bottleneck may form in the bristles of a thermal bristle hair styling device;

[0055] Fig.18 , Fig.19 and Fig. 20 shows how to arrange one or more sensor bristles in a hot brush hair styling device;

[0056] Fig.21 A user input dial is shown;

[0057] Fig.22a and Figure 22b shows an overview of another exemplary hair styling device; and

[0058] Fig.23 An overview of an exemplary hot brush hair styling appliance is shown.

[0059] In the drawings, like elements are always denoted by like reference numerals. DETAILED DESCRIPTION

[0060] The embodiments represent the best ways known to the applicant to put the invention into practice. However, these embodiments are not the only ways to implement the invention.

[0061] Device Overview

[0062] Figure 1a An overview of a hair styling device suitable for implementing one or more of the inventions described herein is shown. However, a hair styling device need not be Figure 1aAny other suitable type of hair styling or hair drying device may be used, such as a heated brush (e.g., a paddle brush), a hair dryer, or a combined hair dryer / styling device (e.g., Figure 2a The device may transfer heat to the user's hair 16 using any of conductive heating, convective heating, or radiant heating (or any combination thereof).

[0063] Figure 1a The device 10 shown is a hair straightener that includes a pair of arms 12a, 12b and a corresponding pair of heater plates 15a, 15b for transferring heat to a user's hair 16 by conduction. The arms 12 are movable between an open position, in which a lock of hair 16 can be inserted between the heater plates 15, and a closed position, in which the lock of hair 16 is sandwiched between and in contact with the heater plates 15. As a result, when the lock of hair 16 is in contact with the heater plates 15, the hair 16 is heated by thermal conduction. Figure 1b and Figure 2b The hair styling device 10 used in the styling process is shown. During use, the user inserts a lock of hair 16 to be styled between the heater plates 15, and then the user will pull the device 10 downwards along this lock of hair 16. If the device 10 is pulled straight downwards along this lock of hair 16, the device 10 can straighten the hair. If the device 10 is rotated so that the hair 16 coming out of the device 10 is forced to change direction, the hair can be curled. The amount of curling depends on the speed at which the user pulls the device 10 along this lock of hair 16 and the amount of rotation of the device 10. It is also observed that the shape / path on which the hair cools has a strong influence on the curling shape. Therefore, the device 10 can be used for straightening and curling hair 16, or providing "body and volume" for hair 16 (if necessary, before or after applying a styling product, such as mousse, gel, wax, hair spray, etc.).

[0064] The user interface 11 is provided to allow the user to set user-defined parameters (if applicable) and to allow the device 10 to output information to the user. For example, the optimal styling settings (such as the optimal styling temperature, power, direction or speed) can be indicated or confirmed to the user via the user interface 11. In some devices, the user can set the desired curl level for their hair 16 via the user interface 11. The user interface 11 can have a dial, button or touch display for allowing the user to input information to the device 10, and the user interface 11 can have an indicator light, display, sound generator or tactile feedback generator for outputting information to the user. In this embodiment, the user interface 11 also includes: a control button or switch 14 to enable the user to turn the device on or off; and an indicator light 13 for indicating whether the power is on.

[0065] The printed circuit board assembly may be provided at any suitable location within the housing of the device 10 for controlling the operation of the device 10 and for controlling the interaction with the user via the user interface 11. In this example, power is provided to the device 10 via a power cord 7 by a power supply located at one end of the device. The power supply may be an AC mains supply. However, in alternative embodiments, the power supply may alternatively or additionally include one or more DC batteries or battery cells (which may be rechargeable, for example from a mains supply or from a DC power supply via a charging lead), thereby enabling the device 10 to be a cordless product.

[0066] As will be described in more detail later, the hair styling device 10 may include one or more sensors for determining the temperature of the user's hair, for sensing ambient temperature, sensing the presence of hair and / or thermal load (a combination of cross-sectional size, velocity, bulk density, moisture content, etc.). It will be appreciated that the user interface 11 may be provided at any suitable location on the device, for example adjacent to the user interface 11. Figure 1a Indicator lights 13 and control switches 14 are shown in FIG. A separate user interface may be provided, for example, as a smartphone application and / or similar application.

[0067] like Figure 2a As shown, the hair styling device 10 is not limited to a device having two arms 12, but can be a single-arm device having bristles 20 for applying tension to the hair as the device 10 is moved through the hair. Figure 2a In the device 10 shown, the bristles 20 extend from the heated surface 5, which heats the hair in contact with it. It is also possible to heat one or more of the bristles 20 to increase the heated surface area available for heating the hair. It is also possible to deliver heated air through the holes in the heated surface 5 or through the holes in the bristles to heat the hair. This allows the hair to be heated by both heated air and conduction when the hair contacts the heated surface 5 or heated bristles 20.

[0068] The present invention is not limited to Figure 1a and Figure 2a The type of hair styling device 10 shown in . For example, a hair styling device 10 that uses radiant heating to transfer heat to the hair may also be used instead (or in addition). More generally, any suitable hair styling device that can transfer heat to the user's hair may be used.

[0069] Example Block Diagram

[0070] Figure 3is a simplified block diagram of the main electrical components of the hair styling appliance 10. As shown, the hair styling appliance 10 includes a power supply 31 that can obtain power from a mains power input. Additionally or alternatively, the power can be derived from a DC power supply and / or a battery, in which case the battery can be charged using the mains power input via an AC to DC converter, which can be external or internal to the hair styling appliance 10.

[0071] In this example, electrical energy is supplied to one or more heaters 32 that heat the heater plate 15 or heating surface 5. In the case where the device 10 delivers a heated airflow that heats the hair 16, the heater 32 heats the airflow generated by one or more fans 33 rotated by one or more fan motors 34. The electrical energy supplied to the heater 32 is controlled by a controller 35 having a microprocessor 36. The electrical energy supplied to the heater 32 can be controlled using one or more power semiconductor switching devices (triacs) to control the application of an AC mains voltage (or a DC voltage obtained from an AC mains or from a battery) to the heater 32. When the hair styling device 10 includes a plurality of heaters 32, a pair of heaters 32 can be powered during the heating phase to reduce the time taken to reach the desired operating temperature. Similarly, if the temperature of the hair contact surface of the device 10 drops below the desired operating temperature when wet hair is in contact with the heater plate 15 or heater surface 5, both heaters 32 can be powered to provide a thermal boost (in a so-called "boost mode") to offset the heat loss of the wet hair and increase the rate of water removal from the hair. At other times, only one of the heaters 32 may be powered to maintain a desired (set point) operating temperature. The device 10 may also include a mode in which both heaters 32 are turned off (deactivated) and the fan 34 generates a cold air flow (air at or near ambient temperature) to cool the user's hair. This mode is a so-called "cold shock" mode, which may be used to set the style of the hair, or may be used to control the evaporation of moisture from the hair to provide finer control over the moisture level. The cold shock mode may also be used to cool a portion of the hair styling device 10 if that portion is overheated. The cold shock mode may be provided using any other suitable method.

[0072] The microprocessor 36 is coupled to a memory 37 (which is typically a non-volatile memory) which stores processor control code for implementing one or more control methods to be described later.

[0073] Figure 3 Also shown is a user interface 11 coupled to the microprocessor 36, for example to provide one or more user input and / or output indications, such as visual indications, tactile indications (vibration) or audible alarms. The outputs may be used to indicate to the user, for example, the overall styling effect.

[0074] To help control the styling process, it is advantageous to accurately measure (directly or indirectly) the current temperature of the user's hair 16 and / or the position of the hair 16 relative to the styling device 10. Therefore, as described in detail below, the hair styling device 10 may be provided with one or more temperature sensors 18 and / or force / proximity sensors 19.

[0075] The temperature sensor 18 can be configured to sense the temperature of the hair 16 by direct contact measurement using, for example, a thermistor, a negative temperature coefficient (NTC) sensor, or a thermocouple. Alternatively or additionally, non-contact measurement (e.g., using an infrared sensor) can be used to measure the temperature of the hair. More generally, the device 10 can include any suitable sensor for measuring the temperature of the hair 16.

[0076] The temperature sensor 18 is configured to measure or sense the temperature of the portion of the device 10 that is in contact with the user's hair and is thermally isolated (to a certain extent) from the heater 32 used to heat the hair. The temperature sensor 18 and / or the force / proximity sensor 19 can be disposed inside the main body portion of the device 10, such as on the heater plate 15, or can be disposed on an external / internal surface of the device 10. The temperature can be measured directly or indirectly. For example, a heat pipe can be used to transfer heat from the component whose temperature is to be measured to the internal sensor 18 by conduction. The force sensor 19 can be disposed internally, such as on the head (or styling portion) of the device 10, and the force sensor can be configured to measure the force applied by the hair 16 on the housing 17 at multiple points. The housing 17 can be made of a soft or deformable material to allow force to be sensed internally.

[0077] The device 10 may also include one or more wetline product dispensers 38 for dispensing liquids such as water or styling products onto the user's hair. The device 10 may be configured to dispense liquid from the dispenser 38 onto the user's hair during the drying or styling process to provide improved control of the moisture level of the hair. Alternatively, the wetline product dispenser may be provided separately from the device, such as as a separate diffuser (e.g., a desktop-based diffuser).

[0078] Finally, the device 10 may have communication circuitry 39 to allow the device to communicate with a remote sensor, remote server, or remote application (e.g., on a mobile phone or tablet computer). The communication circuitry 39 may communicate with the remote device using, for example, Bluetooth, Wi-Fi, and / or 3GPP communication protocols.

[0079] Microprocessor 36 can be configured to communicate with heater 32, fan 33, fan motor 34, moistening product dispenser 38, temperature sensor 18, force / proximity sensor 19, user interface 11, communication circuit 39 and power supply 31 via one or more communication interfaces or transceivers according to software stored in memory 37. Memory 37 can store, for example, one or more operating profiles or parameters. The software stored in memory 37 can include, for example, an operating system and a hair styling control module, which is suitable for implementing one or more control methods described below.

[0080] Those skilled in the art will appreciate that the device 10 need not have Figure 3 For example, if the device 10 is a hair straightener, it may not have the fan 33 and the fan motor 34. Similarly, in some embodiments, the sensors 18 / 19, the moistening product dispenser 38, and the communication circuit 39 may not be present.

[0081] Housing sensing

[0082] Advantageously, the hair styling device 10 detects (or estimates) the amount of curl applied to the user's hair by using a plurality of temperature sensors 18 arranged across an outer housing (or casing) 17 of the hair styling device 16 (e.g., Figure 1a ). Styling performance is determined based on a combination of temperature and angle. Specifically, the heater plate 15 of the styling device 10 heats the hair to above the glass transition temperature of the hair, making the hair plastic, and the angle at which the hair 16 leaves the device 10 is detected from the output of the temperature sensors 18 located around the periphery of the device 10, and based on the angle, the microprocessor 36 can determine the amount of curl applied to the user's hair. More specifically, as described above, if the user pulls the hair styling device 16 along the user's hair without rotating the device 16, the hair styling device 16 will straighten the user's hair, and the heated hair will not contact the housing 17, so none of the temperature sensors 18 installed around the periphery of the housing 17 will register the temperature increase caused by the heated hair contacting the housing 17 near each temperature sensor 18.

[0083] This situation is Figure 4a As shown in the figure, Figure 1a Schematic cross-sectional view of the hair styling device 10 shown in FIG. Figure 4bIf the device 10 is rotated 90 degrees relative to the direction of travel of the user's hair 16 as shown in the figure, the hair will be rotated 90 degrees sharply as it leaves the heater plate 15, which will impart a certain amount of curl to the user's hair 16. The heated hair 16 exiting the device 10 will also contact the housing 17 near the temperature sensor 18-1, which will mean that the temperature sensed by this temperature sensor will be higher than the temperature sensed by the other temperature sensors 18-2 to 18-6 located around the periphery of the housing 17. If the device 10 is as shown Figure 4c If further rotated 90 degrees as shown, the heated hair 16 will be pulled into a tighter curl and will also be in close contact with the portion of the housing 17 near the temperature sensor 18-2. This means that the microprocessor 36 will receive elevated temperatures from the temperature sensors 18-1 and 18-2 compared to the sensor measurements from the temperature sensors 18-3 to 18-6.

[0084] As the device 10 rotates at an increasing angle, when the device 10 rotates about 450 degrees (eg Figure 4dThe microprocessor 36 can also be used to determine the direction in which the user rotates the hair styling device 10, and ... Pressure or force sensors may additionally or alternatively be used to simulate the direction of hair tension. Information about the hair direction may be used to help achieve the symmetry and / or desired styling of a hairstyle (hair styling). For example, information about the hair direction may be used to promote the appropriate symmetry of a hairstyle between the left and right sides of a user's head, or to achieve an alternating curling direction between adjacent locks of hair. Different stylings may require different curling directions, for example, some hairstyles may alternate curling directions between adjacent hair sections, and in the case of other hairstyles, all curls are twisted toward (or away from) the user's face. Therefore, by collecting this information and comparing it with the styling information that the user attempts to copy, the microprocessor may provide useful feedback to the user to teach them how to achieve the desired styling.

[0085] Of course, the amount of curl imparted to the hair is not solely dependent on the amount of rotation of the hair styling device 10 during use. The amount of curl imparted to the hair is also dependent on, among other things, the speed at which the user pulls the device 10 along the lock of hair 16 and the size of the lock of hair 16 inserted between the heater plates 15. The microprocessor can again use the signal from the temperature sensor 18 to estimate these variables while taking into account the size of the lock of hair and the speed at which the lock of hair is pulled through the device 10. Specifically, if the device 10 is pulled slowly along the lock of hair, the hair 16 will heat more, and the housing 17 will also heat more, because the hotter hair 16 will be in contact with the housing 17 for a longer period of time than if the device 10 is pulled along the lock of hair 16 more quickly. Thus, the microprocessor 36 can estimate the speed at which the device 10 is being pulled along the hair strand based on the absolute temperature recorded by the temperature sensor 18 and using predetermined calibration data relating the sensed temperature to the speed of use (which calibration data may be determined at the factory or in a calibration procedure performed on a user in which the user is asked to pull the device through their hair at different speeds).

[0086] The size of the hair strand can be estimated by observing the relative temperatures from the different temperature sensors arranged along the length of the device. In particular, Figure 4e 1 is a plan view showing the arrangement of temperature sensors 18 on the housing 17a of the upper arm 12a. As shown, there are twelve temperature sensors arranged in a 2-dimensional grid, with three sensors 18-1 to 18-3 in the width direction and four sensors 18-1a to 18-1d in the length direction. Of course, the sensors 18 do not have to be arranged in such a regular 2-dimensional grid, and this arrangement is simply shown for illustrative purposes. Depending on the size of the lock of hair, different temperature sensors 18 will register a rise in temperature. Thus, for example, Figure 4e As shown, a small strand of hair may be in contact with housing 17 near only one row of temperature sensors 18 (sensors 18-1b, 18-2b and 18-3b in this figure), so all of these temperature sensors will register an elevated temperature compared to the temperatures recorded by the other temperature sensors 18. Figure 4f and Figure 4g As shown, as the lock of hair 16 grows larger, it will come into contact with the housing 17 and approach more temperature sensors 18, so more temperature sensors 18 in the length direction will register an increase in temperature. Therefore, by observing the difference in temperature measurements obtained from the temperature sensors arranged along the length direction, the microprocessor 36 can determine an estimate of the size of the lock of hair 16.

[0087] Knowing the size of the lock of hair, the speed at which the device 10 is moved along the lock of hair 16, and the amount of rotation of the device during the styling process, the microprocessor 36 can make a good prediction of whether a curl has been achieved, and if so, the degree of curl that has been achieved and how tight the curl is. If the user has input to the microprocessor 36 (via the user interface 11) what kind of curl they wish to achieve, the microprocessor 36 can compare the predicted curl that has been achieved with the desired curl, and then output feedback to the user to help them achieve the curl they wish to achieve. For example, the feedback can be an instruction output on the display to move the device 10 slower along the lock of hair 16, or the feedback can be an instruction to reduce the size of the lock of hair 16 passing through the device 10 at any one time, or the feedback can be to rotate the device 10 more during use, or any combination thereof.

[0088] It should be understood that an array of force / proximity sensors 19 may be used in the same manner as an array of temperature sensors 18 mounted in the housing 17 instead of or in addition to the array of temperature sensors 18 to determine the size of a lock of hair 16 and the amount of rotation of the device 10 during use. The force / proximity sensors 19 may be disposed on an outer surface of the head of the device 10. Alternatively, the force / proximity sensors 19 may be disposed below the housing (which may be made of a soft or deformable material to allow sensing of the presence of hair 16 and / or the force exerted by the hair 16 on a particular portion of the head). The force / proximity sensors 19 cannot be used to sense the speed at which the device 10 moves along the lock of hair 16, but some other sensor may be used to sense the speed, such as a single temperature sensor or motion sensor, etc. Another factor when determining the effectiveness of the curl is humidity. The durability of the curl may be affected by the saturation of the hair and the ambient humidity during styling. By sensing the temperature of the hair as it leaves the device and comparing the temperature of the hair to the plate temperature, the controller can determine the heat capacity of the hair and thereby the humidity of the hair. The humidity sensor can then be used to measure the ambient humidity, and the controller can then adjust the plate temperature to optimize performance for the styling environment. Additionally or alternatively, a solvent applicator (this can be done automatically from the device or manually by the user) can moisten the hair, further maintaining the hair in optimal conditions for the styling environment.

[0089] The energy delivered to the hair (power over a known period of time) can be used as a proxy for hair temperature (e.g., if direct measurement of hair temperature is not available). Combined with measurements of hair segment (lock) size, velocity, and assumptions about moisture content, the power delivered to the hair is proportional to temperature.

[0090] In summary, appropriate temperature sensors 18 and / or force / proximity sensors 19 can be mounted on or within the housing 17 to determine the size or volume of the hair 16 (when the sensors 18 / 19 are arranged along the circumference of the device 10), and these sensors can be used to determine the amount of rotation of the device 10 during use and / or the angle at which the hair 16 leaves the device 10 (when the sensors 18 / 19 are arranged along the length of the housing 17).

[0091] Measuring hair temperature via heater contact

[0092] In prior art hair stylers, a temperature sensor is used to detect the temperature of the heater and this information is fed back to a controller to control the heating of the heater in a closed control loop. The inventors have realised that better control can be achieved if the temperature sensor actually senses the temperature of the user's hair being heated rather than the temperature of an internal part of the heater, as the temperature of the user's hair should be controlled to avoid damage and to ensure that the hair is heated to a sufficient temperature to allow a style to be applied to the hair. If the hair temperature (or an indicator of the hair temperature) can be measured, the control system can provide the following benefits:

[0093] Improved styling performance (e.g. by changing / adjusting the power supplied to the heater 32)

[0094] Reduce hair damage (e.g. by changing / adjusting the power supplied to the heater 32)

[0095] Improved power efficiency (e.g. by varying / adjusting the power supplied to the heater 32)

[0096] Provide user feedback

[0097] Provide diagnostic data

[0098] The inventors have recognized that temperature sensors surrounding the housing 17 can provide a good indication of the temperature of the hair in contact with the housing. For example, in the case shown in FIG. 4 , when the hair leaves the heater plate 15, the temperature sensor 18-1 near the edge of the device 10 can be used to give a reasonable measurement of the hair temperature. Ideally, the temperature sensor should be mounted as close as possible to the edge of the heater plate 15, where the hair has been heated to its hottest temperature. However, conventional wisdom holds that placing a temperature sensor on or near the heater plate 15 will not work because the temperature measurement will be affected by the heat from the heater 32 that heats the heater plate 15. In particular, the heater plate 15 is designed to be a good conductor of heat. Therefore, mounting the temperature sensor 18 at the edge of the heater plate 15 will generally make the measurement too noisy to be used as a measurement of the hair temperature. However, the inventors have recognized that by introducing a thermal bottleneck between the temperature sensor 18 and the heater 32 used to heat the heater plate 15, a more accurate hair temperature measurement can be made.

[0099] The purpose of this design is to accurately measure the signal representing the temperature of the hair. Figure 5a As generally shown in FIG. 1 , if the temperature sensor 18 is mounted in the sensing area 152 at the edge of a conventional heater plate 15, the temperature measurements obtained from the sensor 18 will be relatively noisy due to the heat from the heat source 32 being transferred along the heater plate 15 and heating the temperature sensor 18, resulting in a low sensitivity of the sensor to the hair temperature. However, Figure 5b The purpose of the thermal bottleneck 40 shown is to improve the signal-to-noise ratio and allow for more accurate measurement of the hair temperature signal using the temperature sensor 18 mounted in the sensing area 152 at the edge of the heater plate 15. Figure 1a and Figure 2a 1, but such a thermal bottleneck 40 may be applied to various hair styling devices 10, such as stylers (also known as hair straighteners), curling irons, and heat brushes, etc., equipped with a temperature sensor 18. In this case, the term "signal" is the signal output of the temperature sensor, representing the temperature or index measurement of the hair, and the term "noise" refers to any alternative heat source (particularly the heater temperature) that affects the sensor output.

[0100] In the example shown in FIG. 5 , the thermal bottleneck 40 is located between a sensing region 152 at the edge of the heater plate 15 (which is in contact with the hair during use of the device) and a main portion 151 of the heater plate 15 that is directly heated by the heater 32. Effectively, the thermal bottleneck 40 restricts the flow of heat from the heater 32 along the heater plate 15 to the sensing region 152 at the edge of the heater plate 15, where the temperature sensor 18 is mounted. When a lock of hair 16 is removed from the device 10 and the next lock of hair 16 is placed on the heater plate 15 and heated to a desired temperature (e.g., 185° C.) in the main portion 151 of the heater plate 15 adjacent to the heater 32, the optimal thermal bottleneck 40 maximizes the temperature drop in the sensing region. This arrangement improves the signal-to-noise ratio of the hair temperature measurement, allowing the measured temperature value from the sensor 18 to be used as an indicator of the hair temperature. The greater the temperature drop in the sensing region, the more sensitive (faster and more accurate) the hair temperature indicator measurement becomes.

[0101] Thermal bottleneck

[0102] The following is a detailed description of the thermal bottleneck 40 used in some embodiments. Beneficially, the thermal bottleneck 40 is used to increase / maximize the sensitivity of the temperature sensor 18 by reducing the effect of the heater 32 on the temperature sensor 18.

[0103] In more detail, when using a heater plate 15 with a relatively high thermal mass (e.g. a ceramic heated styling plate or a brush head), the sensitivity of the system to temperature changes during the passage of hair is quite low. In order to increase the sensitivity of the system, a thermal bottleneck 40 is created by reducing the conduction area between the two bodies, which reduces the possible heat flux (shown by Fourier's law of conduction). This allows for greater temperature changes in the bottleneck area when a load (hair) is applied, allowing the sensor in this area to have a better sensitivity. The thermal bottleneck area is also more severely affected by the hair temperature rather than the central heater temperature. This means that the sensor in this area can be relied upon as an indicator of the hair temperature.

[0104] The thermal bottleneck 40 may be implemented as an area with a relatively small cross-sectional area that limits the transfer of heat from the heater 32 to the temperature sensor 18. In one configuration, the thermal bottleneck 40 is provided in the form of a groove or a slot on at least one surface of the heater plate 15. In other words, the thermal bottleneck 40 may be implemented as a blind hole (or groove) or a through hole (or slot) in the heater plate 15, which is located between the sensing area 152 of the heater plate 15 and the main portion 151 connected to or adjacent to the heater 32.

[0105] like Figure 6a and Figure 6bAs shown, the groove forming the hot bottleneck 40 can be provided with a suitable insert 45, such as an I-shaped insert 45-1 or a II-shaped insert 45-2. The insert 45 can be made of a heat insulating material or a metal (such as aluminum) having a relatively low thermal conductivity compared to the material of the heater plate 15. When the hot bottleneck 40 is provided on the surface of the heater plate 15 that contacts the hair 16, the use of the insert 45 can be particularly beneficial because the insert helps to provide a smoother surface to the user's hair than if there were a groove or slot.

[0106] Regardless of which type of hot bottleneck 40 is used, the temperature sensor 18 is typically located on the side of the hot bottleneck 40 opposite the side where the heater 32 is located to optimize the effect of the hot bottleneck 40. Advantageously, the hot bottleneck 40 is provided on the side of the heater plate 15 that contacts the hair to maximize the sensed temperature drop signal.

[0107] Adding the thermal bottleneck 40 means that the sensor area 152 (where the temperature sensor 18 is located) has a larger temperature gradient when a lock of hair 16 is applied to the heater plate 15. Since the sensor 18 has a larger temperature change to read, the signal to noise ratio is improved.

[0108] Temperature sensor type

[0109] Figure 7a and Figure 7b is a schematic plan view of heater 32 and heater plate 15, showing two exemplary sensor designs that can be used to sense the temperature of hair as it leaves the heated surface of heater plate 15. Specifically, Figure 7a A plurality (six in this example) of discrete point temperature sensors 18 are shown positioned along two elongated edges of the heater plate 15. The temperature sensors 18 are provided along both edges because the hair styling appliance 10 is typically designed to be used in either the left or right hand of a user so that hair can pass through the appliance 10 in either direction. Figure 7bTwo continuous (or distributed) sensors 18 are shown along the edge of the heater plate 15. Thus, temperature sensing may be achieved using point sensors such as thermocouples, thermistors and RTDs, or using distributed sensors such as resistance wires, resistance tracks, optical temperature sensors, or a combination thereof. Continuous sensors (distributed sensors) may require only two sensors to fully cover the edge of the heater plate 15, and continuous sensors may be more accurate than the same number of discrete sensors. On the other hand, although multiple sensors may be required to fully cover the edge of the heater plate 15, discrete sensors (point sensors) may provide more accurate readings of the respective hair temperatures of different parts of the styling device. Multiple sensors may also be used to estimate the hair segment (hair strand) size or at least the segment width based on the number of sensors covered by the hair and / or the size of the signal.

[0110] For the sake of completeness, Figure 7a and Figure 7b A thermal bottleneck 40 is also shown, although this is optional in some embodiments. Figure 7a The point sensors 18 in the are each surrounded by an associated thermal bottleneck 40 band (with or without filler 45). Figure 7b The distributed sensor in the heater plate 15 is separated from the heat source / heater element 32 by a thermal bottleneck 40 in the form of a groove or linear slot or gap 40 in the heater plate 15.

[0111] It should also be understood that any other suitable thermal bottleneck 40 may be used, regardless of sensor type or sensor technology. Figure 7a The thermal bottleneck 40 design of the point sensor shown can be used for Figure 7b The distributed sensors shown are used Figure 7b The distributed sensor thermal bottleneck 40 design shown can be used for Figure 7a Point sensor shown. It should also be understood that any other suitable thermal bottleneck 40 may be used.

[0112] Figures 8a to 14c Exemplary designs and concepts for some sensor types are shown.

[0113] Point Sensors

[0114] Figures 8a to 8c An exemplary manner in which discrete sensors may be provided at various points on the heater plates 15 of the styling apparatus 10 is schematically shown. In this example, there are six sensors on each heater plate 15, formed in two rows of three sensors each and along respective ones of the two opposing longitudinal edges. It should also be noted that Figure 8aThe sensors 18 seen in the drawings will not be visible in the actual product as they will be hidden below the surface of the heater plate 15 and concealed by the surrounding housing / casing. Such discrete sensors can provide very accurate measurements of specific areas and can improve control of the overall molding process and / or operation of the device 10. Figure 8b is a cross-sectional view of the heater plate assembly 22, which includes the heater plate 15 (which contacts the user's hair) and a heater carrier 50 which holds the heater plate 15 in the housing / casing of the styling arm. Figure 8c The underside of the heater plate 15 is shown, and the arrangement of the temperature sensor 18 in the sensing area along the edge of the heater plate 15 is shown. Figure 8c Also shown is a heater 32 which provides heat to the heater plate 15 and is held in place against the inner surface of the heater plate 15 by a heater carrier 50 .

[0115] Distributed Sensors

[0116] Figures 9a to 9c There is schematically shown an exemplary manner in which distributed sensors (temperature sensors 18) may be placed on the edges of the heater plates 15 of the styling apparatus 10. In this example, there are two sensors on each heater plate 15, one on each edge. Figure 9b is a cross-section of an exemplary heater plate assembly 22 showing the placement of the temperature sensor 18 relative to the heater plate 15 and the heater 32 (which is located inside the assembled device). Fig.9c The underside of the heater plate 15 is shown, illustrating the location of the temperature sensor 18 and the heater 32 .

[0117] Now go to Fig.10a 10c, the temperature of the hair can be measured using a nickel wire temperature sensor 18 that changes resistance with temperature. In this case, a nickel wire is used as a distributed temperature sensor 18. It should be understood that any other suitable material can be used for the wire. The change in wire resistance can be measured by the microprocessor 36 and then converted into an accurate temperature measurement. This method can be combined with a thermal bottleneck 40 to give a more accurate hair temperature measurement. This represents a low-cost alternative to thermocouples and NTCs, and has the added benefit of averaging the measurement, reducing the possibility of hot spots and heater breakage.

[0118] Fig.10a is a cross-sectional view of the heater assembly 22 showing the heater carrier 50 and the heater plate 15 . Fig.10bis a partial close-up perspective view of the heater carrier 50 showing the temperature sensor wire 18. The temperature sensor wire 18 can be wrapped around the heater carrier 50 to provide tension and hold the heater carrier in place. The wire is pushed toward the heater plate 15 by the heater carrier 50. The heater carrier 50 can be compressed by appropriate means (such as spring clips, screws and / or compression springs, etc.). The wire can be bare wire or can have an outer coating or insulation.

[0119] Fig.11a and Fig.11b Another type of distributed temperature sensor 18 is schematically shown deposited in the sensing area at the two longitudinal edges of the heater board 15 by a process such as thick film printing, chemical etching, etc. Typically, the heater board is made of a conductive material. In order to prevent short circuits between the sensor 18 and the heater board 15, a dielectric layer 55 is provided between the conductive metal heater board 15 and the sensor track 18. In this case, no compression is required to hold the temperature sensor 18 on the heater board 15, because the dielectric layer 55 and the sensor track 18 are thermally bonded to each other and mechanically bonded to the heater board 15. The benefits of this approach include a reduced number of components and a reduced thermal resistance between the sensing track 18 and the heater board surface.

[0120] like Fig.12 As shown, the temperature sensing track 18 can also be placed on the hair side of the heater plate 15. In this case, the hair is directly in contact with the sensing track 18, so the track temperature can more closely represent the hair temperature. In this arrangement, the track 18 measures the hair temperature when the hair is pulled directly over the track 18. It should be understood that conductive vias can be provided through the heater plate 15 to provide an electrical connection between the microprocessor 36 and the temperature sensing track 18. In the example shown in FIG. Fig.11a and Fig.11b In the embodiment shown, the temperature sensing track 18 may be formed as a thick film track or a chemically etched track (formed on a suitable dielectric layer).

[0121] Figures 13a to 13c An exemplary thermal bottleneck design on the hair side of the heater plate 15 is schematically shown, wherein the raised protrusion 51 on the heater carrier 50 is received in the slots 40 formed along the two longitudinal edges of the heater plate 15, which creates the thermal bottleneck described above. At least the raised protrusion 51 of the heater carrier 50 is made of a thermally insulating plastic material, making it more difficult for heat from a heater (not shown) to enter the sensing area 152 of the heater plate 15 where the temperature sensor 18 is mounted.

[0122] Figures 14a to 14cAn exemplary design is shown in which a filler 45 made of a heat insulating material such as plastic is provided in the gap between a main portion 151 of the heater plate 15 adjacent to the heater 32 and a sensing area 152 of the heater plate 15 at or adjacent to which the temperature sensor 18 is mounted. The filler 45 again ensures that the hair side of the heater plate 15 provides a continuous smooth surface for the hair being styled. Fig.14b and Fig.14c As shown, filler 45 extends between the hair side and the heater side of heater plate 15 .

[0123] In the various designs described above, various materials and manufacturing options are available. For example, the heater carrier 50 can be made of polyphenylene sulfide (PPS) or a similar plastic material. The heater plate 15 can be made of metal by machining or die casting, and in some cases by extrusion. The heater plate 15 can also be made of formed sheets. The filler 45 can be made of an insulating material.

[0124] Optical Temperature Sensing

[0125] Another way to sense the temperature of the hair in the sensing area 152 of the heater plate 15 is to use an optical temperature sensor 18. Using an optical temperature sensor reduces the complexity of having to isolate the resistive temperature sensor 18 from the heater power supply 31 (to avoid the risk of electric shock to the user if AC mains power is used), and reduces EMC compatibility issues.

[0126] An example of a suitable optical temperature sensor is a high temperature fiber Bragg grating (FBG) sensor, which is stable at temperatures up to 300°C. FBG sensors reflect the wavelength of light, which depends on external influences such as temperature, pressure or expansion fluctuations on the FBG fiber. FBG sensors are made using holographic interferometry or phase masks that permanently change the refractive index of the optical fiber according to the light intensity. This refractive index is called a fiber Bragg grating. When a broadband light beam is fed into the FBG, induced reflections of certain wavelengths of the coupled light occur at points with a controlled refractive index, and these reflections depend on the temperature of the optical fiber. Therefore, by processing the signals received back from the optical sensor, the microprocessor 36 can determine the temperature of the optical fiber and, therefore, the temperature of the user's hair 16.

[0127] The FBG fiber can be installed in the molding device 10, for example by passing the fiber through a deep drawn hole through the heater plate 15. The fiber is kept in good thermal contact with the heater plate 15 by a suitable mechanical fit, allowing easy assembly. Once assembled, the fiber will be mechanically clamped in place to avoid excessive strain or slippage during use.

[0128] Thermal bottleneck example—hair curling iron

[0129] The above examples of thermal bottlenecks focus on bottleneck designs for hair styling devices as shown in Figure 1. In the case of a curling iron, such as Fig.15a The curling iron shown, the device 10 has a heated outer surface 5 that is heated by one or more heaters mounted in the device. Typically, a heat conductive heater block 51 is mounted in the device, and the outer shape of the heater block 51 matches the shape of the heated surface 5 of the curling iron. A flat shelf 52 is provided, on which a heater (not shown) may be mounted. Heat from the heater is transferred around the periphery of the heater block 51 and through the periphery to the heated surface 5. By placing a pair of slots or grooves 40 at the top of the heater block 51 and / or at the bottom of the heater block 51, the area between the slots 40 will be thermally isolated from the heater (to a certain extent), and therefore a temperature sensor 18 placed in either of these areas will be able to determine an accurate measurement of the hair temperature. The slots / grooves 40 may be blind holes or through holes, and they may be filled with a suitable filler 45 to further limit the conduction of heat from the heater 32 to the sensor 18. The sensor 18 may be a point sensor as described above or a continuous (distributed) sensor comprising a resistive wire / track etched or deposited on or below the heated surface 5 .

[0130] Thermal Bottleneck Example - Thermal Brush

[0131] In addition to stylers and curlers, the bottleneck concept can also be applied to hot brush type hair styling devices 10, similar to Figure 2a The design of the heat brush ensures that the sensor area is (at least partially) thermally isolated from the heater. If the sensor is partially isolated, the sensor will regulate at the heat brush temperature, and the sensor temperature will drop as cooler hair comes into contact with the sensor. If the sensor is fully isolated, the sensor will regulate at the air temperature (because a fully isolated sensor is no longer part of the heater block), and the sensor temperature will increase as heated hair comes into contact with the sensor. In either case, the microprocessor 36 can process the temperature sensor signal from the sensor to determine the hair temperature. Referring now to Figures 16 to 17, the temperature sensor signal from the sensor can be determined by the microprocessor 36. Fig. 20 Further explain the main idea.

[0132] Figure 16a to Figure 16c An exemplary hot bottleneck 40 is shown on the heater plate 15 of the styling device 10. As shown, the hot brush 10 includes a handle portion 23 and a styling portion (or head) 24 having a plurality of bristles including plastic bristles 20, heating bristles 25 thermally coupled to the heater plate 15, and plastic edge bristles 134. Fig.16b A heater plate 15 is shown with heating bristles 25 attached. Fig.16bAlso shown are through holes 27 through which the plastic bristles 20 extend. Fig.16c The heater plate 15 is schematically shown without bristles 25, which shows that the heater plate has a generally convex main heating area 151 with a thermal bottleneck 40 formed by a groove extending around the edge of the heater plate 15 to define a sensing area 152 on which one or more temperature sensors (not shown) can be mounted. Of course, the groove need not extend around the entire perimeter of the heater plate 15, and may instead be located at one or more edge portions of the heater plate where the temperature sensors are to be mounted. Similarly, as an alternative to a groove, the thermal bottleneck may be achieved by adding one or more slots to the heater plate 15.

[0133] Still as an option, and as Fig.17a and Fig.17b As shown, some of the heating bristles 25-1 and 25-2 on the heater plate 15 may be thinner (relative to other heating bristles 20) to create a thermal bottleneck 40. Fig.17b As shown in more detail, the thinner bristles 25-1 and 25-2 are mechanically supported by a plastic overmold 56, which has a lower thermal conductivity. A wire temperature sensor 18 can then be mounted to these thinner bristles 25-1 and 25-2, for example, in the overmold 56 or between the overmold 56 and the thinner bristles 25-1 and 25-2. Advantageously, the overmold 56 has good contact with the user's hair, while the thinner bristles 20-2 take longer to reach the temperature of the heater plate 15 to which the bristles of the hot brush are connected, due to the thermal bottleneck that the thinner bristles 20-2 present to the heater plate 15. Therefore, when the cooler hair contacts these thinner bristles, the thinner bristles will cool towards the temperature of the hair (due to the thermal bottleneck created by the thinner cross-section of these bristles). Therefore, the temperature sensed by the temperature sensor 18 will be a more accurate representation of the temperature of the user's hair than if there were no thermal bottleneck.

[0134] The bristles used for temperature sensing are not necessarily thermally connected to the heater plate 15 . Fig.18 Two co-molded plastic bristles 136-1 and 136-2 are shown for use as temperature sensors 18. These bristles 136 may be disposed on the periphery of the brush head 24, or may form part of a row of plastic bristles 20 located between the heating bristles 25. In a preferred embodiment, Fig.16aThe four outer bristles 134 shown in the figure are replaced by sensor bristles 136 (two on each side of the brush head 24). Of course, additional sensor bristles 136 may be provided if desired. The temperature sensor 18 used in this example comprises a thermocouple mounted to an aluminum element. A plastic support 43 is co-molded onto the aluminum element. A wire (e.g., copper) passes through the core of the plastic support 43 to connect to the temperature sensor 18. The wire can be configured to mate to a conductive pad (e.g., on a printed circuit board in the head 24 of the hot brush) to facilitate connection during assembly. Due to the small thermal mass of the temperature sensor 18 (in this case at the tips of the bristles 136), this design allows for efficient and relatively rapid cooling between each brush stroke through the hair being brushed. Although Fig.18 Two adjacent sensor bristles 136 are shown, but it should be understood that a single sensor bristle 136 may be used instead.

[0135] Fig.19 Another way in which the sensor bristles 136 can be implemented is shown. In this case, the sensor 18 is disposed between a pair of bristles 136 as a temperature-sensitive wire winding. For example, four of the outer bristles 134 can be replaced by such sensor bristles 136 (two on each side of the brush head 24). The bristle pairs 136 can be made of cast aluminum and act as a "thermal bridge" to transfer the heat of the hair downward to the temperature sensor 18. In this example, a wire winding 18 is provided at the base of the bristle pairs 136 for sensing temperature. This arrangement makes it easier to connect the temperature sensor 18 to the microprocessor 36 because the wires connected to the temperature sensor 18 can be routed from the underside of the bristles 136. During use, the efficiency of this design will depend on sufficiently rapid cooling of the sensor bristle pairs 138 between each brushing of the hair.

[0136] Fig. 20 Yet another alternative arrangement of sensor bristles 136 is shown, where the temperature sensing wire winding 18 is provided on the plastic bristles 136. For example, the sensor bristles 136 can be a PPS molding, with the sensor wire wrapped around the sensor brush. The sensor wire 18 is heated by the hair and then cooled to the air temperature. The sensor wire 18 can be connected back to the plate via grooves on the outside of the bristles 136 or through the core of the bristles 136 (e.g. Fig.18 This arrangement has the advantage of simplicity and low thermal mass of the temperature sensor 18 (resulting in improved cooling of the sensor between brushings of the hair). Fig. 20 Two adjacent sensor bristles 136 are shown, but it should be understood that a single sensor bristle may be used instead, or where two or more sensor bristles 136 are used, the sensor bristles 136 may be spaced apart rather than being immediately adjacent to one another. Fig. 20As shown, when multiple temperature sensors 18 are present, they can be located at different heights on the bristles 136. This can improve the temperature reading regardless of the amount of hair passing between the bristles (e.g., by averaging the measurements from multiple sensors 18) and / or allow the amount of hair 16 to be detected (e.g., based on the temperature / temperature difference measured at different heights).

[0137] Hand position detection / gesture sensing

[0138] The temperature sensor 18 and / or the force / proximity sensor 19 may also be used to detect hand position and / or to sense a user's gestures, which may indicate a desired hair styling process. For example, the position of the user's hand and the grip of the handle portion 23 may be detected using force sensors 19 and / or temperature sensors 18 distributed along the handle 23 to obtain one or more of the following potential benefits:

[0139] Grip force is proportional to skill and stress;

[0140] Hand temperature is proportional to stress;

[0141] Grip size as an indicator for different users;

[0142] How the product is held indicates the technique used / the shape created; and

[0143] • How the product is held also indicates which hand is used (left / right).

[0144] It should be appreciated that any other suitable sensor may be used, such as a light sensor, a rotation sensor (e.g., a gyroscope), an acceleration sensor, etc. For example, a strain gauge located between the plates may be used to identify whether the arm 12 is open or closed, and when the arm is open, this information may be used to down-regulate or operate the device 10 at a lower plate temperature, thereby minimizing energy usage and extending battery life.

[0145] The temperature or force sensor 18 / 19 may additionally or alternatively be mounted on the end 26 of the device 10, which is a common location for a user to hold the device 10 while using both hands during a styling operation.

[0146] A force (pressure sensor, capacitive sensor, touch display) sensor may be arranged in some manner within the handle 23 of the styling device 10 to generate gesture-related information about the user's interaction with the device 10 and the resulting hairstyle.

[0147] The sensors may be arranged over a sufficiently large surface area of ​​the handle 23 to capture the contact points of the palm and fingers on the handle 23. The positions of the palm and fingers may be converted into forces and positions which may be used by the microprocessor 36 to:

[0148] Distinguish between straightening or curling behavior.

[0149] • Differentiate between different methods of using styling device 10 to style hair.

[0150] • Identify changes in position during use of the styling device 10.

[0151] Monitor different usage situations of the same user by monitoring the frequency and duration of different baseline hand positions.

[0152] Determining whether the user is an experienced or inexperienced user of the hair styling appliance 10 and changing the operating parameters of the appliance accordingly (e.g., if the user is determined to be inexperienced, the microprocessor 36 may reduce the power supplied to the heater if the hair temperature is found to be above a threshold temperature, thereby preventing an inexperienced user from damaging the hair).

[0153] This data may then be interpreted by the microprocessor 36 on the device or by a processor located external to the device 10 connected to the device 10 via Bluetooth or the like. Information about the user may then be presented to the user on the device or on a peripheral interface (e.g., on a display of a phone or laptop) during or after the styling session.

[0154] Visual, audible and / or tactile indicators may be provided on the styling apparatus 10 to indicate key events related to the user's grip, such as the position of their hands, fingers or the amount of force applied to the handle of the styling device.

[0155] The sensors may be arranged in a large continuous sensing area or in multiple sensing areas around the exposed surface of the hair styling appliance 10. Such a sensor or sensors may be connected to an internal printed circuit board (PCB), but forming a "breakout" / separate PCB, which may be rigid or flexible or printed onto the housing.

[0156] Modification and replacement

[0157] Detailed embodiments and some possible alternatives have been described above. As will be appreciated by those skilled in the art, many modifications and further alternatives may be made to the above embodiments while still benefiting from the invention embodied therein. Therefore, it should be understood that the present invention is not limited to the described embodiments and encompasses modifications that are obvious to those skilled in the art and fall within the scope of the appended claims.

[0158] Device 10 may be partially or completely formed from a unitary structure, such as by 3D printing.

[0159] In the above examples, the device 10 may include a single heater 32 (e.g., in the case of a hot brush, a curling iron device), or may alternatively include two or more heaters 32 (e.g., a hair straightener or curling iron device, or a combined dryer and styling device). More generally, the device 10 may include any suitable device for transferring heat to the user's hair 16, such as any suitable conduction heater, thick film printed heater, steam heater, or radiant (e.g., infrared) heater.

[0160] Throughout the description and claims of this specification, the words "include" and "comprising" and variations of the words, such as "including" and "comprising", mean "including but not limited to", and are not intended to (and do not) exclude other components, integers or steps.

[0161] Figure 1a The device shown uses a plate 15 that is typically used to straighten the user's hair. In other embodiments, the device may use other types of heater plates 15. For example, instead of the heater plate 15, a ribbed surface may be provided so that the device may be used to curl the user's hair during the styling process. Similarly, the heating surface may be defined by a cylindrical heater that is typically used in curling irons.

[0162] Various other modifications will be apparent to those skilled in the art and are not described in further detail here.

Claims

1. A device for styling hair, the device comprising: a handle portion, the handle portion being used to hold the device; A styling part, which is used to style the hair; a heating device for heating the hair styled by the styling part; at least one sensor located on the housing of the device for determining a temperature or position associated with the hair while performing a styling process; as well as A controller is configured to control the device to take at least one action related to the output of the at least one sensor.

2. The device according to claim 1, wherein: The at least one action comprises one or more actions selected from the group consisting of: adjusting the power supplied to the heating device; determining the type of styling process; determining the amount of hair to be heated; determining the type of hair to be heated; determining an angle or curvature at which hair is removed from the housing while performing the styling process; Determining whether the modeling process has achieved a specific modeling; predicting the user's satisfaction with the modeling process; storing output from the at least one sensor for subsequent processing; storing the output to adjust future performance; storing the output to calculate the user's ability; transmitting output from the at least one sensor to a remote device; and / or outputting feedback related to the styling process to a user of the apparatus.

3. The device according to claim 1 or 2, wherein: The controller is configured to control the styling process based on the output of the at least one sensor to obtain a curl compression level for the hair within a threshold range of a target curl compression level.

4. The device according to any one of the preceding claims, wherein: The at least one sensor is located on an edge of a surface heated by the heating device.

5. Apparatus according to any one of the preceding claims, wherein: The heating device is mounted in the styling part, and wherein the at least one sensor is arranged on the styling part.

6. The device according to any one of claims 1 to 4, wherein: The heating device is mounted within the styling portion, wherein the at least one sensor is disposed on the handle portion of the device, and wherein the at least one action comprises determining a hold or orientation of the device.

7. A device for styling hair, the device comprising: a handle portion, the handle portion being used to hold the device; A styling part, which is used to style the hair; at least one sensor mounted on the handle portion for determining information about how a user holds the device during a hair styling operation; as well as A controller is configured to control the device to take at least one action based on the determined information.

8. Apparatus according to any one of the preceding claims, wherein: The at least one sensor comprises a continuous sensor arranged along the width or length of the handle portion and / or the styling portion, or comprises a plurality of sensors arranged on the styling portion and / or on the handle portion.

9. Apparatus according to any one of the preceding claims, wherein: The at least one sensor includes at least one of a thermistor, a negative temperature coefficient (NTC) sensor, a thermocouple, a resistive track or wire, an infrared radiation sensor, a pressure sensor, a force sensor, a proximity sensor, an optical sensor, a light sensor, a humidity sensor, an integrated ohmmeter, an accelerometer, a gyroscope, a magnetometer, and an anemometer.

10. Apparatus according to any one of the preceding claims, wherein: The device includes a memory configured to store a plurality of operating parameters of the device for controlling the styling process; and The device is configured to identify an operating parameter to be used from a stored plurality of operating parameters based on the output of the sensor.

11. The device according to claim 10, wherein: The operating parameter comprises at least one of operating temperature or power or heat output.

12. Apparatus according to any one of the preceding claims, wherein: The apparatus further comprises means for generating an indication to a user whether a desired hair styling result has been achieved based on the output of the at least one sensor.

13. The device according to claim 12, wherein: The indication includes at least one of a visual indication, an auditory indication, and a tactile indication.

14. Apparatus according to any one of the preceding claims, wherein: The sensor is mounted on a circuit board inside the housing.

15. Apparatus according to any one of the preceding claims, wherein: The housing is deformable, and wherein the sensor is a force sensor configured to sense deformation of the housing. [Thermal bottleneck] 16. A device for styling hair, the device comprising: A heating component, the heating component is used to heat the hair in contact with the heating component, the heating component comprises a heating part and a sensing part; a heater for heating the heating portion of the heating member; at least one temperature sensor, the at least one temperature sensor being mounted on the sensing portion; and The heating component includes a heat limiting portion located between the heating portion and the sensing portion, and the heat limiting portion limits the propagation of heat from the heating device toward the sensing portion.

17. The apparatus according to claim 16, wherein: The thermally restrictive portion provides a thermal bottleneck for heat flow from the heating portion to the sensing portion.

18. The apparatus according to claim 16 or 17, wherein: The thermally restricting portion includes a gap, slot or groove between the heating portion and the sensing portion.

19. The apparatus according to claim 18, wherein: The gaps, slots or grooves are at least partially filled with insulating material.

20. Apparatus according to any one of claims 16 to 19, wherein: The heating component includes a heater plate having a heater surface that heats hair in contact with the heater surface.

21. Apparatus according to any one of claims 16 to 20, wherein: The sensing portion is positioned along an edge or peripheral portion of the heating component, and the at least one temperature sensor is configured to measure the temperature of the hair as the hair moves from the heating portion to the sensing portion.

22. Apparatus according to any one of claims 16 to 21, wherein: The device comprises a plurality of bristles, and wherein the heating member comprises at least one of the bristles.

23. The apparatus of claim 22, wherein: The sensing portion is located on or at a base of one or more bristles of the plurality of bristles.

24. Apparatus according to any one of claims 16 to 23, wherein: The at least one temperature sensor is configured to measure the temperature of the hair as the hair moves from the heating portion to the sensing portion.

25. Apparatus according to any one of claims 16 to 24, wherein: The at least one temperature sensor includes at least one of a thermistor, a negative temperature coefficient (NTC) sensor, a thermocouple, a resistive track or wire, an infrared radiation sensor, and an optical sensor.

26. Apparatus according to any preceding claim, wherein: The device is a hair straightener, a hair curler, a hair dryer, a hot paddle brush, a hot round brush, a heater roller, or a combination thereof.

27. Apparatus according to any preceding claim, wherein: The at least one sensor is a point sensor or a continuous sensor extending along the length of the sensing portion. [Sensor Bristles] 28. A device for styling hair, the device comprising: a handle portion, the handle portion being used to hold the device; a styling portion, the styling portion being used to style hair, the styling portion comprising a heating component and a plurality of bristles, the heating component being used to heat hair in contact with the heating component, the plurality of bristles being used to apply tension to the hair, wherein at least one of the bristles is a sensor bristle for sensing a temperature of the hair; as well as A controller is configured to control the device to take at least one action based on the sensed hair temperature.

29. The apparatus of claim 28, wherein: The at least one sensor bristle includes a temperature sensor mounted on or at a base of the sensor bristle.

30. Apparatus according to claim 28 or 29, wherein One or more of the bristles are heating bristles thermally coupled to the heating component.

31. The apparatus of claim 30, wherein: The at least one sensor bristle is a heating bristle thermally coupled to the heating component.

32. Apparatus according to any one of claims 28 to 31, wherein The controller is configured to control a heat output of a heater that heats the heating member according to the sensed hair temperature.

33. A method for styling hair, characterized in that Use of an apparatus as claimed in any preceding claim.

Images