Device and method for drying or styling hair

Abstract

The present disclosure relates to a device for drying or styling hair, the device comprising: a heating mechanism for heating the hair to reduce the moisture level of the hair; and a controller configured to control the device to take an action for controlling a moisture level of the hair based on a target moisture level.

Description

Technical Field

[0001] The present invention relates to a device for drying and / or styling human (or conceivably animal) hair, for example after washing it or as part of a styling process. That is, the hair may be wet (or "towel dried") before use of the invention, and may subsequently be dried and / or styled using the invention. This drying and styling of the hair may be performed by the user on his own hair, or, for example, by a hair stylist.

[0002] It should also be noted that the term "wet" as used herein should be broadly interpreted to include not only hair wetted with water, but also hair wetted with liquids other than water. For example, hair can be wetted with solvent-based colorants that can be used for drying and / or styling according to 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 the hair straightener to achieve the desired styling effect, while at higher temperatures, there is a risk of permanent damage to the hair.

[0004] Similarly, a heated brush or hair dryer can also be used to style the hair by heating the hair to a temperature suitable for styling. Hair is typically styled from a wet state, for example after the user has washed the hair. After being heated by the hot air from the hair dryer, a so-called "cool shot" of cool air can be used to set the hairstyle in place.

[0005] However, regardless of the type of hair styling device and the technique used to style the hair, over time the style will begin to deteriorate. For example, curly hair that has been straightened using a hair straightener will gradually return to its original curly state. Therefore, there is a need for improved hair styling devices that can achieve longer lasting hair styling results.

[0006] 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

[0007] 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.

[0008] The disclosed method enables a substantial increase in the durability of a hairstyle and / or the styling ability of a hair heated styling tool by controlling the moisture level of the hair based on a target moisture level. The inventors have recognized that by controlling the moisture level of the styled hair based on an ambient moisture level (e.g., ambient humidity), improved durability of the hairstyle and improved styling performance can be achieved. More specifically, the inventors have recognized that when the moisture level of the hair is controlled to match the ambient moisture level (or within a threshold range of the ambient moisture level), a longer lasting hairstyle can be achieved. Advantageously, by controlling the moisture content of the hair to balance with the ambient humidity, the durability of the hairstyle (and the overall styling ability of the device) is improved.

[0009] In one aspect, the present invention provides a device for drying or styling hair, the device comprising: a heating mechanism for heating the hair to reduce the moisture level of the hair; and a controller configured to control the device to take actions for controlling the moisture level of the hair based on a target moisture level.

[0010] The controller may be configured to control the moisture level of the hair within a threshold range of a target moisture level.The target moisture level may correspond to the ambient moisture level.

[0011] The controller may be configured to control an operating parameter of the heating mechanism based on the target moisture level to control the moisture level of the hair.

[0012] The controller may be configured to control the heating mechanism to reduce the difference between the moisture level of the hair and a target moisture level.

[0013] The controller may be configured to control the heating mechanism to reduce the heat output or operating temperature of the heating mechanism as the humidity level approaches the target humidity level.

[0014] The device may include a memory configured to store a plurality of operating parameters of the device; and the device may be configured to identify an operating parameter to be used from the stored plurality of operating parameters based on the moisture level of the hair or based on a target moisture level of the hair to control the moisture level of the hair towards the target moisture level. The operating parameter may include at least one of an operating temperature and a heat output.

[0015] The device may further comprise at least one sensor for outputting a sensor output that varies with the moisture level of the hair; and the device may be configured to determine the moisture level of the hair based on the sensor output.

[0016] The device may include a temperature sensor for sensing the temperature of the hair; and the device may be configured to determine the moisture level of the hair based on the sensed temperature of the hair. The device may be configured to determine the moisture level of the hair based on a measured change in the temperature of the hair over time.

[0017] The heating mechanism may include a heatable surface for transferring heat to the hair; wherein the device includes a temperature sensor for sensing the temperature of the heatable surface; and wherein the device is configured to determine the moisture level of the hair based on the temperature of the heatable surface. The temperature sensor may include at least one of a thermistor, a thermocouple, and an infrared radiation sensor.

[0018] The device may comprise a plurality of temperature sensors for measuring the temperature of the heatable surface at two or more regions of the heatable surface, and the device may be configured to determine the moisture level of the hair based on the measured temperatures.

[0019] The device may be configured to obtain a heat load at two or more areas of the heatable surface, and the device may be configured to determine the moisture level of the hair based on the obtained heat load.

[0020] The apparatus may also include a mechanism for achieving a target moisture level.

[0021] The target humidity level may be an ambient humidity level; the device may include a sensor for outputting a sensor output that varies with the ambient humidity level; and the device may be configured to use the sensor output to determine the ambient humidity level. The sensor for outputting a sensor output that varies with the ambient humidity level includes a hygrometer.

[0022] The device may comprise a capacitive sensor for outputting a sensor output that varies with a current moisture level of the hair; and the device may be configured to determine the current moisture level of the hair using the sensor output from the capacitive sensor that varies with the current moisture level of the hair.

[0023] The device may be configured to generate an airflow across or through the hair, and the capacitive sensor may be configured to sense the humidity level of the air that has flowed across or through the hair.

[0024] The device may include an optical sensor; and the device may be configured to determine the moisture level of the hair based on the light intensity of light passing through the hair measured by the optical sensor, based on the light intensity of light reflected from the hair and / or based on the light intensity of light passing through the air near the hair.

[0025] The device may also include a light source for emitting light that passes through the hair, reflects from the hair, and / or passes through the air near the hair.

[0026] The optical sensor may be configured to sense light intensity indicative of the fluid or wetting product to determine the amount of fluid or wetting product in the hair.

[0027] The device may comprise a sensor for measuring an electrical resistance that varies with the current moisture level of the hair; and the device may be configured to determine the moisture level of the hair based on the measured resistance.The sensor for measuring electrical resistance may comprise a hygroscopic conductive layer.

[0028] The device may be configured to apply an electric field to the hair; wherein the device is configured to measure at least one dielectric property of the hair using the applied electric field; and wherein the device is configured to determine the moisture level of the hair based on the measured dielectric property.

[0029] The device may further comprise means for producing an indication to the user that the moisture level of the hair is within a threshold range of the target moisture level.

[0030] The controller may be configured to control the device to control the moisture level of the hair by outputting an indication of the current moisture level of the hair to a user.

[0031] The controller may be configured to control the device to control the moisture level of the hair by outputting to the user an indication of the current moisture level of the hair relative to a target moisture level.

[0032] The device may be configured to output an indication to a user of instructions for operating the device, and the device may be configured to determine the output instructions based on the wetness level of the hair or based on a target wetness level.

[0033] The apparatus may include a user interface. The user interface may be operable by a user to input an indication of a target moisture level.

[0034] The device may further comprise a fluid dispenser for increasing the moisture level of the hair by dispensing fluid onto the hair.The controller may be configured to control the device to increase the moisture level of the hair using the fluid dispenser before heating the hair using the heating mechanism.

[0035] The device may be configured to vibrate the hair to disperse the fluid in the hair. The device may include a vibrating member for vibrating the hair. The device may be configured to generate an airflow to vibrate the hair.

[0036] The device may be a hair straightener, a hair dryer, a heated paddle brush, a heated round brush, heated rollers, or a curling iron.

[0037] Target moisture levels can be pre-configured and stored in the device.

[0038] The apparatus may be configured to receive a target moisture level from a separate device.The apparatus may be configured to receive a target moisture level that has been input by a user into a smartphone application.

[0039] In another aspect, the present invention provides an apparatus for drying or styling hair, the apparatus comprising: a heating mechanism for heating the hair to reduce the moisture level of the hair; a sensor for outputting a sensor output that varies with the current moisture level of the hair; and a controller configured to:

[0040] i) using the sensor output to determine the current moisture level of the hair; and

[0041] ii) Outputting an indication to the user which is dependent on the determined current moisture level of the hair.

[0042] The indication may be an indication of the current moisture level of the hair.

[0043] The device may be configured to achieve a target wetness level of the hair; and

[0044] The indication may be an indication of the difference between a target moisture level for the hair and the determined current moisture level for the hair.

[0045] The target humidity level may correspond to the ambient humidity level.

[0046] The indication may include at least one of a visual indication, an audible indication, and a tactile indication.

[0047] The apparatus may be configured to receive a target moisture level from a separate device.The apparatus may be configured to receive a target moisture level that has been input by a user into a smartphone application.

[0048] In another aspect, the present invention provides a method for drying or styling hair, the method comprising: heating the hair to reduce a moisture level of the hair; and controlling the moisture level of the hair based on a target moisture level.

[0049] In another aspect, the present invention provides a method of drying or styling hair, the method comprising: heating the hair to reduce the moisture level of the hair; and outputting an indication of the current moisture level of the hair to a user.

[0050] On the other hand, the present invention provides a method for drying or styling hair, the method comprising: heating the hair to reduce the moisture level of the hair; obtaining a target moisture level of the hair and a current moisture level of the hair; and outputting to a user an indication of the difference between the target moisture level of the hair and the current moisture level of the hair.

[0051] In another aspect, the present invention provides an apparatus for drying or styling hair, the apparatus comprising: a heating mechanism for heating the hair to reduce the moisture level of the hair to equilibrium with the ambient moisture level.

[0052] On the other hand, the present invention provides a device for drying or styling hair, comprising: a first arm and a second arm opposite to each other, the first arm and the second arm opposite to each other are suitable for moving between an open configuration and a closed configuration, in the open configuration, the first arm and the second arm receive a wet hair segment therebetween, and in the closed configuration, the first arm and the second arm are adjacent to the hair, so that in use, when the first arm and the second arm are in the closed configuration, the first arm and the second arm form an inter-arm chamber, and the hair passes through the inter-arm chamber in use, and wherein the air flow duct is arranged in at least one of the first arm and the second arm and along at least one arm; a conveying mechanism, which is used to convey the air flow along the duct in at least one of the first arm and the second arm and then convey the air flow to the inter-arm chamber; a sensor, the sensor is used to sense whether the first arm and the second arm are in the open configuration or the closed configuration; and a control mechanism, the control mechanism is used to control the conveying mechanism to change the air flow according to whether the first arm and the second arm are in the open configuration or the closed configuration.

[0053] The control mechanism (which may be, for example, a control circuit or a microprocessor) is configured to cause the delivery mechanism to provide a first airflow rate when the first arm and the second arm are in an open configuration, and to provide a second airflow rate greater than the first airflow rate when the first arm and the second arm are in a closed configuration. In some embodiments, the control mechanism is configured to cause the delivery mechanism to change the airflow between the first flow rate and the second flow rate in a stepwise variation or in a smooth variation.

[0054] According to another aspect, the present invention provides a device for drying or styling hair, comprising: an airflow conduit within and along at least one first arm of the device; a delivery mechanism that delivers airflow along the conduit; a sensor for sensing an operating mode of the device; and a control mechanism that controls the delivery mechanism to change the airflow based on the output of the sensor. The sensor can be selected from the group consisting of an accelerometer, a gyroscope, and a switch; and wherein the sensed operating mode is whether the device is currently in motion, or whether the device is currently in a specified orientation, or whether the device is currently near or on a surface.

[0055] According to another aspect, the present invention provides a device for drying or styling hair, comprising: a first arm and a second arm opposite to each other, the first arm and the second arm opposite to each other are suitable for moving between an open configuration and a closed configuration, in the open configuration, the first arm and the second arm receive a wet hair segment between them, and in the closed configuration, the first arm and the second arm are adjacent to the hair, so that in use, when the first arm and the second arm are in the closed configuration, the first arm and the second arm form an inter-arm chamber, and the hair passes through the inter-arm chamber during use, and wherein the air flow duct is arranged in at least one of the first arm and the second arm and along at least one arm; a conveying mechanism, the conveying mechanism is used to convey the air flow along the duct in at least one of the first arm and the second arm and then convey the air flow to the inter-arm chamber; at least one vent, air from the inter-arm chamber can leave the device through the at least one vent; and an air diffuser, which is installed between the vent and the inter-arm chamber to diffuse the air leaving the device.

[0056] The air diffuser may comprise a thermally conductive material such as copper, aluminium or a ceramic material. The air diffuser may be arranged near the outlet of the dried and styled hair from the device to provide conduction and convection cooling of the hair as it leaves the device, thereby setting the hairstyle produced by the device.

[0057] In one embodiment, the device further comprises mutually opposing hair contact members arranged on the first arm and the second arm, the mutually opposing hair contact members being arranged to come together when the first arm and the second arm are in a closed configuration, and preferably wherein at least one of the hair contact members comprises a conductive heater.

[0058] The device may include: a first hair contact member and a second hair contact member arranged on a first arm, and corresponding opposite first hair contact members and second hair contact members arranged on the second arm, wherein the opposite hair contact members arranged on the first arm and the second arm are arranged to be gathered together when the first arm and the second arm are in a closed configuration; when the first arm and the second arm are in a closed configuration, an inter-arm chamber is located between the first hair contact member and the second hair contact member of the first arm and the second arm; wherein at least one hair contact member includes a heat applying mechanism, which is used to apply heat to the hair segment sandwiched between the hair contact members when the first arm and the second arm are in a closed configuration during use; and wherein one or both of the arms also include an airflow guiding structure, which is arranged to receive an airflow from a corresponding duct and guide the airflow from a first direction (D1) substantially parallel to the length of the corresponding arm to a second direction (D2) from the corresponding arm toward the opposite arm into the inter-arm chamber.

[0059] In another aspect, the present invention provides a device for drying or styling hair, comprising: a first arm and a second arm opposed to each other, the first arm and the second arm opposed to each other being adapted to move between an open configuration and a closed configuration, in which the first arm and the second arm receive a wet hair segment between them, and in which the first arm and the second arm are adjacent to the hair, so that in use, when the first arm and the second arm are in the closed configuration, the first arm and the second arm form an inter-arm chamber, and the hair passes through the inter-arm chamber in use, and wherein an air flow duct is arranged in at least one of the first arm and the second arm and along at least one arm; a conveying mechanism, the conveying mechanism being used to convey an air flow along the duct in at least one of the first arm and the second arm and then a delivery mechanism, the heater and the at least one heater plate being turned on during normal use; and wherein, when the sudden cold starter switch or sensing mechanism is activated by the user of the device, both the delivery mechanism and the at least one heater plate are turned on and the heater is turned off.

[0060] According to another aspect, the present invention provides a device for drying or styling hair, comprising: a first arm and a second arm disposed opposite each other, the first arm and the second arm disposed opposite each other being adapted to move between an open configuration and a closed configuration, in which the first arm and the second arm receive a wet hair segment therebetween, and in which the first arm and the second arm are adjacent to the hair, so that in use, when the first arm and the second arm are in the closed configuration, the first arm and the second arm form an inter-arm chamber, and the hair passes through the inter-arm chamber in use, and wherein an air flow conduit is provided in at least one of the first arm and the second arm and along at least one of the arms; a conveying mechanism for conveying an air flow along a conduit in at least one of the first arm and the second arm and subsequently conveying the air flow into the inter-arm chamber; an air heater, the air heater being adapted to heat the air flow;

[0061] at least one vent through which air from the inter-arm chamber can exit the device; and an air diffuser mounted between the vent and the inter-arm chamber to diffuse air exiting the device; at least one conduction heater, the at least one conduction heater being configured to heat the hair by conduction during use; control electronics for controlling the device; and a quench starter switch or sensing mechanism for activation by a user of the device, wherein each of the delivery mechanism, the air heater and the at least one conduction heater is turned on during normal use; and wherein, when the quench starter switch or sensing mechanism is activated by the user of the device, both the delivery mechanism and the at least one conduction heater are turned on and the air heater is turned off. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0063] Figure 1a shows an overview of an exemplary hair styling device;

[0064] Figure 1b The hair styling device is shown in use;

[0065] Figure 1c shows a simplified block diagram of a hair styling appliance;

[0066] Figure 2 A flow chart illustrating a method of controlling the moisture level of hair is shown;

[0067] Figure 3 shows a flow chart illustrating another method of controlling the moisture level of hair;

[0068] Figure 4 A flow chart illustrating another method of controlling the moisture level of hair is shown;

[0069] Figure 5a A user input dial is shown;

[0070] Figure 5b shows a simplified schematic diagram of an apparatus for steam drying hair;

[0071] Figure 6 shows a table stored by the device;

[0072] Figure 7 An element of a user interface for indicating the moisture level of hair is shown;

[0073] Figure 8 shows a graph of hair temperature versus drying time;

[0074] Fig. 9 A flow chart illustrating a method of controlling the moisture level of hair during a drying / styling process is shown;

[0075] Fig.10 Shows Fig. 9 A variant version of the flowchart;

[0076] Fig.11a is a perspective overview of a combined hair drying / styling device including opposed drying / styling arms in an open configuration, wherein each arm includes a pair of conductive heaters and an airflow directing structure;

[0077] Fig.11b The arms are shown in a closed configuration. Fig.11a Devices;

[0078] Fig.11c shows the apparatus of Figure 11 in use;

[0079] Fig.12 is a longitudinal perspective cross-sectional view of the lower arm of the device of FIG. 11 , illustrating the major internal components of the device and the airflow within the device during use;

[0080] Fig.13 yes Fig.12 a side cross-sectional view of the distal end of the lower arm shown and illustrating the direction of airflow through the distal end of the lower arm;

[0081] Fig.14 is a transverse cross-sectional view through an arm of the device of FIG. 11 in a closed configuration and also illustrating the direction of airflow;

[0082] Fig.15 is a transverse cross-sectional view through an arm of the device of FIG. 11 having a diffuser to diffuse air exiting a vent of the device; and

[0083] Fig.16 A simplified block diagram of the electronic components of the hair styling tool shown in Figure 11 is shown.

[0084] In the drawings, like elements are always denoted by like reference numerals. DETAILED DESCRIPTION

[0085] 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.

[0086] Throughout this disclosure, when referring to the moisture level of hair, the term "moisture level" is used to refer to the amount of bound water and / or unbound water on the hair, or to the humidity of the air near the hair (or between the hair strands). The moisture level of the air can be referred to as the "humidity level". Similarly, the ambient humidity level can also be referred to as the "ambient humidity level".

[0087] As used herein, the expressions "drying the hair," "drying the hair," or "reducing the moisture level of the hair," etc., may refer to the removal of "unbound" water that is present on the outside of the hair when wetted, or the removal of "bound" water that is present within individual hair strands and that may interact with the hair when the hair is heat styled. It is not necessary to remove "bound" water when drying the hair, although some removal of bound water may occur during the drying or styling process.

[0088] Device Overview

[0089] Figure 1a An overview of a hair styling device suitable for implementing one or more methods of the present invention is shown. However, the hair styling device need not be Figure 1a Any other suitable type of hair styling or hair drying device may be used, such as a heated brush (e.g., a paddle brush) or a hair dryer. The device may use any of conductive heating, convection heating, and radiant heating (or any combination thereof) to transfer heat to the user's hair.

[0090] Figure 1a The device 10 shown is a hair straightener comprising a pair of arms 12a, 12b and a corresponding pair of heater plates 15a, 15b for transferring heat to the user's hair by conduction. Figure 1b The device 10 is shown in use during a styling process. In use, the device 10 will typically receive a section (lock) of hair 16.

[0091] The user interface 11 is provided to allow the user to set user-defined parameters and to allow the device to output information to the user. For example, the moisture level of the user's hair can be indicated to the user via the user interface 11, and / or the user can set a desired moisture level for his hair 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 to display whether the power is on.

[0092] The printed circuit board assembly may be disposed at any suitable location within the housing of the device 10 and carries control circuitry 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 17 by a power source located at one end of the device. The power source may be an AC mains power source. However, in alternative embodiments, the power source may include one or more DC batteries or battery cells (which may be rechargeable, for example from a mains power source or from a DC power source via a charging lead), thereby enabling the device 10 to be a cordless product.

[0093] As will be described in more detail later, the device may include one or more sensors for determining the moisture level and / or temperature of the user's hair and / or for sensing the ambient moisture level. 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's hair. Figure 1a The indicator light 13 and the control switch 14 are shown in FIG.

[0094] The present invention is not limited to Figure 1a . For example, a device that alternatively (or additionally) uses heated air to transfer heat to the hair may be used, such as a hair styling device described in the applicant's earlier application WO2021 / 019239, the contents of which are incorporated herein by reference. When heated air is used to heat the user's hair, the device may include a heater having an electrically powered heating coil (or any other suitable type of heating element) that is operable to heat the air drawn in by the fan assembly. More generally, any suitable device capable of transferring heat to the user's hair may be used.

[0095] The device may include bristles for improving the styling performance of the device. The bristles guide the hair as it passes over the bristles so that the user has better control over the styling of the hair and can use a wider range of styling techniques. For example, the device may be a heated brush having a plurality of heated bristles.

[0096] Example Block Diagram

[0097] Figure 1c is a simplified block diagram of apparatus 10 showing the main components of apparatus 10 .

[0098] As shown, the device 10 includes a power supply 38 that obtains power from a mains input. Alternatively, power may be obtained, for example, from a battery, in which case the battery may be charged using the mains input via an AC to DC converter, which may be external or internal to the device 10.

[0099] In this example, electrical energy is supplied to one or more heaters 25 that heat the plate 15. In the case where the device 10 is a hair dryer, the heater 25 heats the airflow generated by one or more fans 27, which are rotated by one or more fan motors 28. The electrical energy supplied to the heater 25 is controlled by a controller 36 having a microprocessor 62. The electrical energy supplied to the heater 25 can be controlled using one or more power semiconductor switching devices (triacs) to control the AC mains voltage (or a DC voltage obtained from the AC mains or from a battery) applied to the heater 25. When the device 10 includes a plurality of heaters 25, a pair of heaters 25 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 plate 15 drops below the desired operating temperature when wet hair contacts the plate 15, both heaters 25 can be powered to provide a thermal boost (in a so-called "boost mode") to offset the heat loss of the hair and increase the rate of water removal. At other times, only one of the heaters 25 can be powered to maintain the desired operating temperature. The device 10 may also include a mode in which both heaters 25 are turned off (deactivated) and the fan 27 generates a cold airflow (air at or near ambient temperature) to cool the user's hair. This mode is a so-called "cold shock" mode, which can be used to set the styling of hair, or can be used to control the evaporation of moisture from the hair to provide a more refined control of the moisture level. If the device 10 overheats, the cold shock mode can also be used to cool a portion of the device 10. The cold shock mode can be provided using any other suitable method. The cold shock mode can be provided using an actively cooled hair contact surface. For example, the cold airflow generated by the device can be used to cool the hair contact surface. A peltier device can be used to quickly cool the hair contact surface to provide the cold shock mode.

[0100] The microprocessor 62 is coupled to a memory 63 (which is typically a non-volatile memory) that stores processor control code for implementing one or more control methods to be described below.

[0101] Figure 1c Also shown is a user interface 11 coupled to a microprocessor 62, for example to provide one or more user controls and / or output indications, such as visual indications or audible alarms. The outputs may be used to indicate to the user when, for example, the moisture level of the user's hair is within a predetermined range of a target moisture level.

[0102] In order to help control the moisture level of the user's hair, it is advantageous to obtain an accurate measurement of the current moisture level of the user's hair (directly or indirectly). Therefore, as described in detail below, the device 10 can be provided with one or more humidity sensors 64. The device 10 can also include one or more temperature sensors 65. The temperature sensor 65 can be a non-contact type sensor (e.g., an infrared sensor) for sensing the temperature of the user's hair, and / or for sensing the temperature of a portion of the device 10 (e.g., the temperature of the heater plate 15). One or more humidity sensors 64 and / or one or more temperature sensors 65 can be disposed inside the main body portion of the device 10, or can be disposed on an external surface of the device 10. The temperature measurement of a portion of the device 10 can be measured directly or indirectly. For example, a heat pipe can be used to transfer heat from the portion whose temperature is to be measured to an internal sensor by conduction.

[0103] The device 10 may also include one or more wetline product dispensers 29 for dispensing liquid (such as water or styling products) onto the user's hair. The device 10 may be configured to dispense liquid from the dispenser 29 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).

[0104] Finally, the device 10 may have communication circuitry 67 to allow the device to communicate with a remote sensor, remote server, or remote application (e.g., on a mobile phone). The communication circuitry 67 may communicate with the remote device using, for example, Bluetooth, Wi-Fi, and / or 3GPP communication protocols.

[0105] The microprocessor 62 can be configured to communicate with the heater 25, the fan 27, the fan motor 28, the moistening product dispenser 29, the humidity sensor 64, the temperature sensor 65, the user interface 11, the communication circuit 67 and the power supply 38 via one or more communication interfaces or transceivers according to the software stored in the memory 63. The memory 63 can store, for example, one or more operating profiles or parameters. The software stored in the memory 63 can include, for example, an operating system and a moisture level control module, which is suitable for implementing one or more control methods described below.

[0106] As will be appreciated by those skilled in the art, the device 10 need not have Figure 1c For example, if the device 10 is a hair straightener, the fan 27 and fan motor 28 are not required. Similarly, in some embodiments, there may be no sensors 64, 65, no moistening product dispenser 29, and no communication circuit 67.

[0107] Moisture Level Control - Overview

[0108] Figure 2 1 is a flow chart illustrating a method of controlling the moisture level of a user's hair during a styling or drying process. Advantageously, the moisture level of the user's hair is controlled based on a target moisture level, which may be an ambient moisture level (e.g., a current or future ambient moisture level), or based on a moisture level set by the user (or desired). The inventors have discovered that controlling the moisture level of the user's hair based on a target moisture level may result in a more durable hair styling effect. For example, at the end of a styling process, the moisture level of the user's hair may be controlled within a predetermined threshold (range) of the ambient moisture level. Alternatively, the moisture level of the user's hair may be controlled to be a predetermined amount higher than the ambient moisture level at the end of the styling process to account for subsequent evaporation of the hair as it cools to ambient temperature. In another alternative, the moisture level of the user's hair may be controlled to be a predetermined amount lower than the ambient moisture level at the end of the styling process to account for subsequent increases in the moisture level of the hair caused by subsequent additions of moisturizing product by the user.

[0109] Therefore, refer to Figure 2 In the method shown, in step S201, a target humidity level is obtained. The target humidity level may be obtained by reading a predetermined humidity level from a memory 63 of the device 10, by receiving the target humidity level from a remote server (via the communication circuit 67), by receiving the target humidity level from a user via the user interface 11, or by a sensor that senses the ambient humidity level. The sensor may be mounted within the device 10 (such as the sensor 64) or may be remote from the device 10. Where the ambient humidity level is to be sensed, the ambient humidity level preferably corresponds to the humidity of the air in which the user is expected to spend most of their time, rather than the ambient humidity level in the area in which the device 10 is located during the styling / drying process. For example, when a user styles their hair in a bathroom where the ambient humidity level (humidity) is relatively high, but expects to spend most of their time in another location where the ambient humidity is much lower, it is advantageous to control the humidity level of the user's hair based on the ambient humidity at the location where the user is expected to spend most of their time, rather than based on the humidity level of the bathroom. To this end, the sensor may be remote from the device 10, or the user may set the target humidity level via the user interface, or the local humidity level of the country or geographical area in which the user is located may be obtained from the remote server.

[0110] Where at least one sensor 64 is mounted within device 10 for sensing ambient humidity levels, at least one sensor 64 is ideally positioned away from where a user grips device 10 in normal use to mitigate the effect of moisture from the user's hands on the measurement of ambient humidity.

[0111] In step S202, the device 10 is controlled to control the moisture level of the user's hair based on the target moisture level obtained in step S201. Step S202 may include determining the current moisture level of the user's hair, comparing the moisture level to the target moisture level, and then taking control actions to control the drying of the hair. The control actions may be to vary the amount of heat applied to the hair using the heater 25 and / or output an indication (audible, visual or tactile) to the user to limit the number of passes required to reach the target moisture level and / or output an indication (audible or visual) when the moisture level of the sensed user's hair is within a predetermined threshold (range) of the target moisture level. A detailed method of determining the current moisture level of the user's hair is described below.

[0112] In an alternative approach, instead of sensing the current moisture level of the user's hair, the device 10 may assume an initial moisture content (e.g., by using a predetermined starting moisture level based on the hair being "towel dry") and then control the device 10 based on this assumed moisture level and the target moisture level. Alternatively, if the hair begins to dry and the device 10 then moistens the hair using liquid from the moisturizing product dispenser 29, the device 10 may determine the starting moisture level of the hair based on the amount of liquid applied to the hair. In a simpler embodiment, the device 10 may simply take different control actions based solely on the target moisture content without using any sensed or expected moisture level of the hair. For example, for a first target moisture level, the device 10 may be programmed to heat the plate 15 to a temperature of 160 degrees Celsius and output an indication to the user via the user interface 11 that they should pass each lock of hair through the heater plate 15 three times; and for a second (different) target moisture level, the device 10 may be programmed to heat the plate 15 to a temperature of 135 degrees Celsius and output an indication to the user via the user interface 11 that they should pass each lock of hair through the heater plate 15 four times. Detailed methods of controlling the moisture level of the user's hair during a styling or drying process based on target moisture levels will also be described below.

[0113] Figure 3 Another flow chart illustrating a method of controlling the moisture level of hair during a styling or drying process is shown, wherein the device 10 is also operable to increase the moisture level of the user's hair.

[0114] Step S301 and Figure 2 The same as step S201.

[0115] In step S302, the current moisture level of the user's hair is determined. A detailed method of determining the current moisture level of the user's hair is described below. For example, the device 10 may include one or more sensors 64, 65, and the outputs from these sensors may be processed to determine the moisture level of the user's hair.

[0116] In step S303, the device 10 increases the moisture level of the user's hair. For example, the device 10 may determine that the user's hair is dry, or that the moisture level of the user's hair (determined in step S302) is below the desired target moisture level (obtained in step S301). As described above, the device 10 may be configured to increase the moisture level of the user's hair by dispensing fluid (or "wetting" product) from the moistening product dispenser 29 onto the user's hair. For example, the fluid may be dispensed in response to an input from the user (e.g., pressing a button provided on the device), or may be dispensed under the control of a controller of the device 10 in response to determining that the moisture level of the user's hair is below the ambient moisture level.

[0117] Step S304 and Figure 2 Same as S202.

[0118] Advantageously, when the device 10 is operable to increase the moisture level of the hair, greater flexibility is achieved in the use of the device 10. For example, when the device 10 is configured to control the moisture level by heating the hair to reduce the moisture level (e.g., to match the ambient moisture level) in step S304, the hair must have a moisture level greater than the target moisture level before heating begins. Advantageously, when the user's hair has a moisture level that is initially less than the target moisture level, in step S303, the device 10 can be used to increase the moisture level of the hair to greater than the target moisture level in order to perform step S304.

[0119] Figure 4 Another flow chart illustrating a method of controlling the moisture level of hair is shown, wherein an indication of the moisture level is output to a user.

[0120] Steps S401 and S402 are respectively Figure 3 Steps S301 and S302 are the same.

[0121] In step S403, after the moisture level of the hair has been determined in step S402, an indication of the moisture level of the hair is output to the user. The indication may indicate, for example, the current moisture level of the hair on an arbitrary scale. The indication may be, for example, a visual indication, an auditory indication and / or may include tactile feedback. The user may use information about the moisture level to achieve better control over the moisture level of the hair. For example, when the device 10 is a hair dryer, the user may use the hair dryer to dry the hair until the hair dryer indicates that the hair is within a threshold range of the target moisture level, at which point the user may decide to stop the drying process (or start drying another section or another strand of hair). Advantageously, the indication of the moisture level of the hair also reduces the risk of the user causing damage to the hair due to over-drying the hair. It should be understood that in Figure 4 In the exemplary method shown, the device 10 does not necessarily include a controller for controlling the moisture level of the user's hair by controlling the heater 25, but can output an indication of the current moisture level of the hair to the user, thereby continuously guiding the user to control the moisture level of the hair towards the target moisture level.

[0122] Obtain target moisture level

[0123] Methods for obtaining a target (eg, ambient) moisture level for hair will now be described. Any of these methods may be used, for example, for the above-mentioned Figures 2 to 4 Any one of steps S201, S301 and S401.

[0124] As mentioned above, the device 10 may be provided with a sensor 64 for sensing the ambient humidity level. For example, the device may be provided with a hygrometer (or any other suitable type of humidity sensor) for measuring the ambient humidity. In a particularly advantageous example, the sensor 64 is positioned away from the active styling area (e.g., in the Figure 1a 64, the device 10 may be configured to sense the ambient humidity level repeatedly (e.g., periodically or intermittently). For example, the device 10 may be configured to sense the ambient humidity level repeatedly when the device is connected to mains power. After the device 10 has obtained the ambient humidity level using the sensor 64, the device 10 may store the measured ambient humidity level in the memory 63 as a target humidity level for the user's hair.

[0125] In addition to a separate sensor 64 for sensing the moisture level of the user's hair, a sensor 64 for sensing the ambient moisture level may be provided. Alternatively, the sensor 64 for sensing the ambient moisture level may be configured to additionally sense the moisture level of the user's hair (e.g., a single sensor may be provided to sense both the moisture level of the user's hair and the ambient moisture level). For example, the sensor 64 may be configured to repeatedly (e.g., periodically or intermittently) sense the ambient moisture level when the device 10 is not in use by the user, and may be configured to sense the moisture level of the user's hair when the device is used to dry / style hair. Advantageously, when the sensor 64 is configured to repeatedly sense the ambient moisture level when the device 10 is not in use, the effect of heat and / or evaporated water from the styling area (and / or moisture from the user's hands) on the measurement of the ambient moisture level is reduced (or completely mitigated) even when the sensor is located in the styling area or near where the user holds the device, thereby improving the accuracy of the measurement of the ambient moisture level.

[0126] Alternatively, the device may be pre-configured with a target humidity level (e.g., pre-configured with a stored ambient humidity level that may vary by country or geographic region). The target humidity level may be configured (e.g., at the time of manufacture, or via a subsequent software update) to be the average ambient humidity level at the geographic location of the end user. For example, when the device is intended for a user in the United Kingdom, the target humidity level may be set to the average humidity level in the United Kingdom. When the device is assigned a stock keeping unit (SKU) code, the average ambient humidity level may be pre-configured based on the assigned SKU. The device 10 may use the communication circuit 67 to change the average ambient humidity level depending on the time of year and the geographic region in which the device is located.

[0127] The device 10 may be configured to communicate with sensors within the building to obtain a target moisture level using the communication circuit 67. For example, the device 10 may be configured to communicate with a heating, ventilation, and air conditioning (HVAC) system to obtain a target moisture (humidity) level.

[0128] The device 10 can be configured to determine the current location of the device 10, for example, using location data obtained using a GPS chip or obtained via a connected mobile phone application. The device 10 can also be configured to estimate the location of the device 10 based on the input voltage and / or frequency of the mains power supply connected to the device. Then, the device 10 can obtain the current local weather conditions (e.g., current local humidity) of the estimated location in order to obtain an accurate measurement of the ambient humidity level of the day in the geographical area. For example, the device 10 can use the communication circuit 67 to communicate with an external server via the Internet (or any other suitable form of communication network) to obtain the current local weather conditions. The device 10 can also or alternatively be configured to obtain future local weather conditions for determining the target ambient humidity level. For example, the device can be configured to obtain the ambient humidity level later in the day. The device can be configured to calculate or obtain the average ambient humidity level over a period of time based on a local weather forecast, and can be configured to set the average ambient humidity level as the target humidity level of the user's hair. The device can be configured to store information indicating the daily life of the user, and the device can be configured to determine the target humidity level of the user's hair based on the daily life. For example, the stored information may include an indication of the time of day when the user is typically inside (e.g., in a lower humidity environment) or the time of day when the user is typically outside (e.g., in a higher humidity environment). For example, the device may be configured to obtain information indicating that the user typically stays indoors on rainy days, and when it rains (or when the weather forecast indicates that it is likely to rain), set the target humidity level to the typical ambient humidity level of the indoor environment. The device may be configured to determine the target humidity level for the user's hair based on the user's calendar or schedule (which may be obtained, for example, via a connected smartphone application).

[0129] In another alternative, the target moisture level for the hair may be manually set by the user of the device 10. For example, Figure 5a A dial 70 of the user interface 11 is shown, which can be operated by the user to set a target moisture level for the hair. For example, the dial 70 can be disposed on the housing of the device 10 (or, conceivably, can be disposed on a remote controller). In this example, the dial 70 is operable to select a moisture level between any values ​​of 1 and 5, wherein 1 corresponds to a relatively low moisture level and 5 corresponds to a relatively high moisture level. Any other suitable element of the user interface 11 that allows the user to input a target moisture level can be used. For example, the device 10 can be configured to receive a target moisture level from a user using a connected smartphone application via the communication circuit 67.

[0130] Advantageously, in this example, when the user anticipates that they will be spending a large portion of the day in a high humidity level environment, the user can manually increase the target moisture level for the hair, thereby enabling an improved match between the moisture level of the hair and the expected ambient humidity level, which results in a longer lasting hair styling effect. For example, when the user anticipates spending some time outdoors after a rain (which results in a higher ambient humidity level), the user can increase the target moisture level for the hair.

[0131] Determine and control the moisture level of the hair

[0132] A detailed method of controlling the moisture level of hair during the styling or drying process (e.g., using Figure 1a The moisture level of the hair may be controlled based on the ambient moisture level (or target moisture level) obtained according to any of the above methods.

[0133] Device 10 can control the moisture level of the hair by heating the hair to reduce the moisture level, or by adding one or more fluids to the hair to increase the moisture level using moisturizing product dispenser 29. Device 10 can also control the moisture level of the hair by using fan 27 and fan motor 28 to blow air at ambient temperature through the hair to control the evaporation rate.

[0134] Device 10 can be configured to reduce the moisture level of hair by using superheated steam drying alternatively (or additionally), thereby controlling the moisture level of hair. Superheated steam drying (SSD) utilizes steam heated above its boiling point as a drying medium to remove moisture from hair. Compared with using hot air for drying, steam drying is a more energy-efficient technology that reduces the degradation of hair structure, provides more uniform hair drying, and reduces the risk of over-drying hair. Waste steam that has been used to reduce the moisture level of hair can be recycled for further use, further improving the energy efficiency of the method. In addition, oxidation and denaturation of hair that may occur when using hot air to dry hair can be avoided or reduced. Other benefits of steam drying include sterilization and deodorization of hair. In addition to steam drying (e.g., while steam drying), other methods of transferring heat to hair (e.g., using a conductive plate) and / or controlling the moisture level of hair can also be used.

[0135] Figure 5b A simplified schematic diagram of an apparatus for steam drying hair is shown. Figure 1a The device 10 (and Figure 1c ) can be configured to use Figure 5bThe device shown in the figure is used to steam dry the hair of the user. As shown in the figure, the device includes a heater 50, a fan / blower 51 and a closed steam drying system 52. Steam is produced by a boiler (not shown in the figure), but any other suitable steam-producing mechanism (means) can also be used to produce it. The heater 50 is configured to heat the steam from the boiler to generate superheated steam. The fan / blower 51 is configured to drive the steam flow through the device 10. The superheated steam is used to reduce the moisture level of the hair in the closed steam drying system 52. The closed steam drying system 52 can include, for example, a chamber (for example, a pressurized chamber) for receiving the superheated steam flow. The superheated steam reduces the moisture level of the user's hair in the chamber. The steam used to reduce the moisture level of the user's hair in the closed steam drying system 52 is discharged from the chamber, and removed from the device, and / or the fan / blower 51 is used to circulate back to the heater 50, so as to be reheated and reused in the closed steam drying system 52 subsequently. In this example, the use of a heat exchanger to recover energy from the purged steam improves the energy efficiency of the device. The heat recovered at the heat exchanger can be used by the heater 50 to heat the steam, and / or can be used by the boiler to generate steam. The device 10 can also include a mechanism for removing condensate at the heat exchanger.

[0136] It is contemplated that the styling process and moisture level control can be performed using separate devices. For example, a brush can be used to style the hair, and a separate device (e.g., a hair dryer) can be used to perform moisture level control of the hair.

[0137] Any suitable sensor or arrangement of sensors may be used, the output of which may be processed to determine the moisture level of the user's hair. However, it should be understood that the device 10 need not necessarily include a sensor 64 for measuring moisture level. For example, the device may heat the hair prior to styling according to a predetermined operating profile based on a target moisture level and a typical moisture level of wet hair. The predetermined operating profile for achieving a particular target moisture level (which may include, for example, heater temperature, duration of heating the hair, or any other suitable operating parameter) may be determined experimentally in advance and stored in the memory 63 of the device 10. For example, a mapping of target moisture levels to operating profiles may be stored in the memory 63 of the device 10 (e.g., as a stored table, such as described below). Figure 6 However, providing the device 10 with one or more sensors 64 for measuring the moisture level of the user's hair allows for more precise control of the moisture level.

[0138] The controller 36 of the device 10 may control the moisture level of the hair based on the target moisture level and the current moisture level of the user's hair using any suitable control method. For example, the device 10 may be configured to operate according to a pre-configured stored operating profile (which may include, for example, heater temperature, duration of heating the hair, or any other suitable operating parameter) based on the target moisture level and the current moisture level to control the moisture content of the hair towards the target moisture level. Controlling the amount of heat delivered to the hair, and thereby controlling the moisture level of the hair (by controlling the amount of evaporation) may be achieved by, for example, controlling the heated air flow heated by the heater 25, by controlling the temperature of a heater plate heated by the heater 25 that contacts the hair, and / or by controlling the power output of the radiant heater 25. In a particularly advantageous example, the device 10 includes a thick film printed heater for heating the hair, such as the heater described in the applicant's earlier application (application number GB2115266), the contents of which are incorporated herein by reference. Advantageously, the thick film printed heater has a relatively low thermal mass, thereby allowing more sensitive control of the hair temperature, and therefore more sensitive and precise control of the moisture level.

[0139] Figure 6 An example of a table that maps a target moisture level and a current moisture level to a corresponding operating temperature of the device 10 is shown. The table is stored in a memory 63 of the device 10. The controller 36 is configured to use the stored table to determine the operating temperature to be used based on the target moisture level obtained and based on the current moisture level obtained. The table does not necessarily include the target moisture level; alternatively, the table may simply include the current moisture level and the corresponding operating temperature. In other words, the device may store a mapping between the current moisture level of the user's hair and an operating temperature for use in adjusting the moisture level of the user's hair (e.g., an operating temperature previously determined experimentally for adjusting the moisture level of the hair to match a typical ambient moisture level). In another alternative, the table may simply map the difference between the target moisture level and the current moisture level to a corresponding operating temperature.

[0140] Although Figure 6 The table shown includes operating temperatures (e.g., the temperature of the heater plate 15, or the temperature of the heated air heated by the heater 25), but the table may include any other suitable operating parameters for controlling the moisture level of the user's hair (e.g., the power output value of the heater 25) instead of or in addition to the operating temperatures. The table may alternatively map the target moisture level and / or the current moisture level to an index corresponding to a set of operating parameters stored separately in the memory 63.

[0141] In the first row of the table, the current humidity level is higher than the target humidity level. However, because the current humidity level is relatively high, the device 10 is set to operate at a reduced temperature of 120°C to avoid water cavitation ("sizzle"). In the second to fourth rows of the table, the current humidity level is still higher than the target humidity level, and the corresponding operating temperature is set to 185°C to provide effective styling capabilities and drive the current humidity level toward the target humidity level. In the last row of the table, the current humidity level is the same as the target humidity level, so the operating temperature is set to ambient temperature (i.e., the heater 25 is turned off and allowed to cool).

[0142] The device 10 may output an indication to the user that the hair has reached the target moisture level (or is within a threshold range of the target moisture level) via the user interface 11. For example, the device 10 may output an audible tone or visual indication (or any other suitable type of indication, such as tactile feedback) that the current hair section or lock being dried is within the threshold range of the target moisture level, and therefore the user should stop the styling / drying process for that hair section.

[0143] Instead of the controller 36 directly controlling the moisture level of the user's hair, the controller 36 may instead output information to the user via the user interface to allow the user to control the way they use the device 10, thereby indirectly controlling the moisture level of the user's hair. Figure 7An arrangement of indicator lights 71 is shown, which can form part of the user interface 11 to provide an indication of the current moisture level of the hair. In this example, two indicator lights 72 of the indicator lights are on, and three indicator lights 73 of the indicator lights are off, thereby indicating that the current moisture level of the hair section being styled / dried is 2 / 5 on an arbitrary scale (5 represents wet hair). The user can then continue to heat the same hair section or lock of hair until the indicated moisture level is at the desired level on an arbitrary scale. The arrangement 71 can also provide an indication of a target moisture level, or an indication that the hair has reached a target moisture level (or within a threshold range of the target moisture level). For example, one or more indicator lights can light up in red when the moisture level of the hair is below the target moisture level, light up in green when the moisture level of the hair is at the target moisture level, and light up in blue when the moisture level of the hair is above the target moisture level. By observing the indication of the current moisture level and the indication of the target moisture level, the user can control the moisture level of the hair towards the target moisture level, thereby producing a more lasting styling effect. However, the target moisture level need not necessarily be indicated to the user. For example, the user may already have access to the current ambient humidity independently of the weather report, in which case the current moisture level of the hair need only be indicated to guide the user in controlling the moisture level of the hair towards the ambient humidity to achieve improved styling performance. For example, if the weather report indicates that today's weather will be dry and sunny, the user may aim to dry / style each lock of hair until the indicated moisture level is at level 1 on the arbitrary scale; whereas if the weather report indicates that today's weather will be wet, they may aim to dry / style each lock of hair until the indicated moisture level is at level 3 on the arbitrary scale.

[0144] The indication of the current moisture level (and optionally the target moisture level) of the hair need not necessarily be a visual indication to the user.For example, audio or tactile feedback, or any other suitable type of feedback, may be provided via the user interface 11 .

[0145] The device 10 may be configured to obtain the current moisture level of the user's hair using one or more of the methods described below. When a plurality of the methods described for obtaining the moisture level of the user's hair are used and the results are combined, a more accurate and reliable determination of the moisture level of the hair may be achieved (e.g., by calculating an average of the moisture levels obtained using the different methods). The following describes a method for determining the moisture level of the user's hair and the method may be used, for example, as a Figure 3 as part of step S302 or as a Figure 4When the sensor used to determine the moisture level of the user's hair is also used to measure the ambient moisture level, it should be understood that the method described below can also be used to measure the ambient moisture level (eg using a capacitive sensor method).

[0146] Heat load

[0147] The moisture level of the hair can be determined by measuring the heat load on one or more components of the device 10. The energy required to heat the hair depends on the amount of moisture retained within the hair. For a given lock of hair heated by the device 10, the heat load is related to the temperature and moisture content of the lock of hair. Thus, by measuring the heat load, the moisture level of the hair can be determined (estimated) via a suitable lookup table or calculation that previously determines and relates the measured heat load to the moisture level of the hair. For example, for a given lock of hair heated by the device 10, the heat load is related to the temperature and moisture content of the lock of hair. Figure 1a In a hair straightener of the type shown in , the moisture level of the hair may be determined based on the heat load on the heater plates 15a, 15b.

[0148] Heat load and thus determine the moisture level of hair depends on the amount of heated hair. The moisture level of hair can be based on the estimation of the typical amount of hair received by the device in normal use, determined (estimated) via a suitable lookup table or calculation. Alternatively, a pair of sequentially arranged heater plates can be used to improve the accuracy of determining the moisture level. When the user pulls the device over the hair, the hair passes through the first plate of the sequentially arranged heater plates, and then passes through the second plate of the sequentially arranged heater plates. Therefore, the hair is first heated by the first heater plate, and then heated by the second heater plate. Due to the fact that some water is removed from the hair at the first heater plate before the hair passes through the second heater plate (that is, the moisture level of the hair at the first heater plate is greater than the moisture level of the hair at the second heater plate), the heat load on the first heater plate is greater than the heat load on the second heater plate. Advantageously, since the first plate and the second plate both receive the same amount of hair, this difference heat load can be used to determine the moisture level of the hair in a manner independent of the amount of hair being heated.

[0149] More generally, the device (10) may include a plurality of temperature sensors (or sensors for measuring heat load) for measuring the temperature at two or more regions of a heatable surface (or multiple heatable surfaces) that the hair passes sequentially (i.e., a lock of hair first passes through a first region of the two or more regions and then passes through a second region of the two or more regions). The device may be configured to determine the moisture level of the hair based on the measured temperature (or measured heat load), for example based on the temperature difference or heat load between the regions. The use of the measured temperature or measured heat load to determine the moisture level may be combined with measurements of the moisture level of the user's hair obtained using other methods to increase the accuracy of determining the moisture level.

[0150] When the device 10 is used to style hair, the heat load may be determined by monitoring changes in temperature of each heater plate 15 (eg, using one or more temperature sensors) and / or by monitoring the power delivered to each heater plate 15 .

[0151] As an alternative to using sequentially arranged heater plates to eliminate the effect of a user using locks of different volumes, the device 10 may include a sensor for sensing the amount of hair in the lock being heated by the device so that the moisture level of the hair can be more accurately determined based on the heat load.

[0152] Hair temperature

[0153] The moisture level of the hair can be determined by monitoring the change in the temperature of the hair over time when heat is applied to the hair. The temperature sensor 65 can be configured to sense the temperature of the hair. The temperature sensor 65 can be configured to measure the temperature of the hair 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.

[0154] Figure 8 A graph of the temperature of the hair relative to the drying time when heat is transferred to the hair is shown. As described below, the hair passes through a warming period, and then passes through a first drying period and a second drying period. The first drying period corresponds primarily to the removal of unbound water, and the second drying period corresponds primarily to the removal of bound water. By using the temperature sensor 65 to measure the change in the temperature of the hair over time when heat is transferred to the hair, the amount of unbound water and bound water in the hair (which corresponds to the moisture level of the hair) can be determined by the controller 36.

[0155] Figure 8 The following stages are shown:

[0156] "Warming up phase": During this phase (points A to B), the device 10 uses the heater 25 to transfer heat to the hair, raising the temperature of the hair to the temperature of the drying phase (during which phase change of the liquid occurs). Figure 1a When a hair straightener of the type shown in is used to transfer heat to the hair, the heater plates 15a, 15b are typically operated at a temperature below about 100°C to 135°C (e.g., 120°C) to avoid water cavitation (so-called "hiss") from occurring. This warm-up period can be identified by the controller 36 using the output of the temperature sensor 65 that senses an increase in the temperature of the hair after the device 10 initially begins to transfer heat to the hair.

[0157] "Drying Period 1": During this phase (points B to C), the device 10 continues to transfer heat to the water on the hair, but the temperature of the hair remains relatively constant. This is because the evaporation of unbound water limits the increase in temperature. This first drying period can be identified by the controller 36 using the output of the temperature sensor 65: the temperature sensor senses a constant temperature of the hair after the initial warm-up period.

[0158] "Drying Phase 2": In this phase (points C to E), the unbound water has evaporated and the bound water on the hair begins to evaporate and be driven out of the hair fiber. In this phase, the temperature of the hair increases from the initial temperature (corresponding to the equilibrium temperature during the drying phase 1) to the final temperature (at point E). The controller 36 can identify this phase using the output of the temperature sensor 65: the temperature sensor senses an increase in the hair temperature, which is higher than the constant temperature maintained during the drying phase 1. In other words, the start of this phase can be identified by identifying the increase in temperature, which starts at the "elbow" of point C.

[0159] By monitoring the temperature of the hair over time, the moisture level of the hair can therefore be determined or estimated during the styling / heating process. When the amount of hair received by the device is known (or estimated), the moisture level of the hair at point B can be determined based on the heat output of the heater 25 and the time taken to heat the hair from the temperature at point A to the temperature at point B. The moisture level of the hair in drying period 1 (between points B and C) can be determined based on the amount of heat transferred to the hair from the device 10 (which can be used to calculate the amount of evaporation of unbound water), the determined or estimated moisture level of the hair at point B, and the amount of time that has elapsed since the start of drying period 1. Similarly, the moisture level of the hair in drying period 2 can be determined based on the amount of heat transferred to the hair from the device 10, the determined or estimated moisture level of the hair at point C (which is known because point C corresponds to the point at which all unbound water has been removed from the hair and removal of bound water begins), and the amount of time that has elapsed since the start of drying period 2. Thus, a particular moisture level may be achieved by heating the hair at a particular heat transfer rate for a corresponding amount of time after the "elbow" at point C is detected. A table mapping moisture levels of the hair to the time elapsed after point C in the graph may be experimentally determined in advance and stored in the memory of the device 36. Alternatively, an experimentally determined equation may be stored in the memory 36.

[0160] As described above, the determined moisture level may be output to a user to allow the user to control use of the device 10, or may be used by the controller 36 to control operation of the device 10 to achieve a target moisture level for the lock of hair.

[0161] Capacitive Sensors

[0162] The device may be configured to determine the moisture level of the hair by measuring capacitance.The moisture sensor 64 may comprise a capacitive sensor.

[0163] When moisture from the hair contacts a suitable material, the dielectric properties of the material change (and therefore the capacitance changes), which is proportional to the amount of water in contact with the material. Any suitable material that changes in capacitance in response to a change in moisture level can be used (for example, any suitable polymer or metal oxide between a pair of conductive electrodes can be used). By arranging the capacitive sensor at a position where it will contact moisture from the hair, the moisture level of the hair can therefore be determined based on the measured capacitance change via a suitable lookup table or calculation, which predetermines and associates the measured capacitance with the moisture level of the hair. The capacitance of the material can also depend on temperature. A temperature sensor 65 can be used to measure the temperature of the capacitive sensor in order to account for this effect, thereby achieving a more accurate measurement of the moisture level. Preferably, the capacitance of the material increases linearly (or approximately linearly) as the moisture level increases, because this allows easy mapping between the sensed capacitance and the determined moisture level.

[0164] The capacitive sensor is not necessarily arranged to contact the user's hair. For example, the device 10 may include a fan for generating an airflow through and / or through the hair, and the capacitive sensor may be arranged to sense the humidity level of the air that has been blown through and / or through the hair, which provides an indication of the humidity level of the hair.

[0165] Optical Sensors

[0166] The moisture sensor 64 may comprise an optical sensor.The device 10 may be configured to determine the moisture level of the hair by measuring the amount of light reflected from the hair, by measuring the attenuation of light through the hair, and / or by measuring the attenuation of light through the air near the hair.

[0167] The moisture sensor 64 may include a light emitter and a light detector (i.e., a light / optical sensor). The light emitter is configured to illuminate the hair with light (including light of any suitable wavelength, and not limited to visible light), and the light detector is configured to detect light reflected from the hair. For example, the light emitter and light detector may be disposed on a styling arm (e.g., from a Figure 1a The plates 15a, 15b shown in the figure are recessed) or may be arranged on the hair contact surface of the brush. By measuring the amount of light reflected from the hair, the moisture level of the hair can be determined via a suitable lookup table or calculation, which determines in advance and relates the measured light to the moisture level of the hair.

[0168] The light emitter and light detector may alternatively (or additionally) be configured to measure the attenuation of light passing through the air near the hair to measure the local humidity near the hair. It should be understood that according to the Beer-Lambert law, the amount of light attenuation is proportional to the moisture level (humidity) of the air.

[0169] The light emitter can be configured to illuminate the hair with light of a specific wavelength (or light of a specific distribution of wavelengths). The light detector can be configured to detect, for example, Lyman alpha light or other water (or hydrogen) absorption or emission peaks to determine the moisture level of the hair. For example, water absorption peaks at 1950 nm, 1450 nm, 1200 nm, and / or 970 nm can be measured.

[0170] Advantageously, the optical sensor may also be configured to determine the hair segment size, hair color, hair texture, hair gloss and / or hair alignment of the hair by measuring the amount of light passing through the hair or the amount of light reflected from the hair. The target moisture level of the user's hair may be set using one or more hair segment sizes, hair colors, hair gloss and / or hair alignment determined using the optical sensor. For example, a corresponding target moisture level (or a scaling factor of the target moisture level obtained using another method to be applied) that results in a more durable hairstyle may be experimentally determined in advance for any one (or any combination) of the determined hair segment size, hair color, hair gloss and / or hair alignment. The optical sensor may also be used to measure the speed of the hair passing through the device (i.e., the speed at which the user moves the device through the hair) by measuring the change in light reflected from the hair over time (in a manner similar to how an optical mouse for a computer senses the speed / position of the mouse). The determined speed may be used to determine an operating parameter for controlling the moisture level of the user's hair. For example, if the hair is moving relatively slowly through the device, the operating temperature of the device 10 may be lowered to reduce the risk of overheating the hair (or over-drying the hair).

[0171] The optical sensor may also be configured to determine the distance (e.g., proximity) between the device and the user's head. For example, the optical sensor may be configured to sense an amount of ambient light that decreases as the device 10 moves closer to the user's head. The device 10 may be configured to input the output from the sensor into a stored equation to determine the distance between the device 10 and the user's head. Alternatively, the device 10 may use a stored lookup table that maps sensor measurements of ambient light levels to corresponding distances between the device 10 and the user's head.

[0172] The optical sensor can be configured to sense the amount of the wetting product in the user's hair. For example, the optical sensor can be configured to sense the chemical characteristics of the wetting product (e.g., sensing the amount of light of one or more wavelengths as a characteristic of the wetting product) to determine the amount of the wetting product in the hair (e.g., by a controller or processor of the device 10 configured to receive an output from the sensor). The optical sensor can be used to sense the fluorescent characteristics of the wetting product. Determining the amount of the wetting product can be used as an alternative measurement of the amount of moisture in the user's hair. For example, by measuring the amount of the wetting product in the hair as the moisture is removed from the hair, the overall moisture level of the user's hair can be determined or estimated. The wetting product can be applied to the hair before and / or during the styling process. The wetting product can be dispensed to the hair by the device 10 (e.g., according to any method described below for dispensing fluids or wetting products), or can be manually infiltrated into the hair by the user (e.g., as part of a shampoo or conditioner applied to the hair before the device 10 is used to style the hair).

[0173] Resistance measurement

[0174] The moisture sensor 64 may be configured to measure changes in electrical resistance (or resistivity) to determine the moisture level of the hair. The moisture sensor 64 may include a DC resistance sensor for measuring the moisture level of the hair.

[0175] The change in resistivity measured between the two electrodes can be used to establish a value for relative humidity. The humidity sensor 64 can include a material that exhibits a change in resistance when the humidity level changes. The resistance of the material can change inversely with the humidity. By measuring the change in resistance of the material, the humidity level can be determined via a suitable lookup table or a predetermined calculation that correlates the measured resistance value with the humidity level of the hair. The humidity sensor 64 can include a hygroscopic conductive layer in the form of a polymer humidity sensing film, for example, mounted on a substrate. However, any other suitable material can be used. For example, the material can include an electro-ceramic material, a perovskite ceramic material, a thick film ceramic material, a ceramic material to which a catalyst is added, a doped / undoped semiconductor film, or an organic / inorganic hybrid composite material.

[0176] Time, frequency or amplitude domain reflectometry

[0177] The moisture sensor 64 may include a plurality of electrodes for passing electromagnetic waves through the hair to determine the moisture level of the hair. Electromagnetic waves of any suitable frequency may be used. The speed and intensity of the waves and the changes in the frequency of the waves as the waves travel between the electrodes are directly related to the dielectric properties of the hair, which in turn depend on the moisture level of the hair and can therefore be used to determine the moisture level of the hair via a suitable lookup table or calculation that predetermines and relates the speed and intensity of the waves to the moisture level of the hair.

[0178] For example, the moisture level of the hair can be determined by measuring the dielectric loss of the entire hair.The relationship between dielectric loss and moisture level can be previously measured experimentally for a specific device configuration and used to populate a lookup table that correlates the measured dielectric loss to moisture level.

[0179] The electrodes may be arranged, for example, Figure 1a 10. However, any other suitable arrangement of electrodes may be used. For example, the electrodes may be arranged as bristles of a brush, or as printed tracks on the surface of the device 10.

[0180] Air temperature sensing

[0181] For devices configured to transfer heat to the hair using a heated airflow (e.g., the device described in the applicant's earlier application WO2021 / 019239), the temperature of the airflow after the airflow has transferred heat to the hair (referred to as the "outflow air temperature") is proportional to the amount of heat transferred to the air via the heater 25, inversely proportional to the flow rate of the air through the device, and inversely proportional to the amount of heat transferred to the hair. When a quantity of wet hair is released into the heated airflow, the latent heat of evaporation causes the outflow air temperature to decrease compared to when dry hair is released into the heated airflow. Thus, by measuring the outflow air temperature, the moisture level of the hair can be determined or estimated via a suitable lookup table or calculation that previously determines and correlates the measured outflow air temperature with the moisture level of the hair.

[0182] A hair sensor for sensing the amount of hair heated by the airflow may also be provided to improve the accuracy and reliability of determining the hair moisture level obtained using the method (since the amount of heat transferred to the hair also depends on the amount of hair received by the device 10).

[0183] Measurements of hair moisture level obtained using any of the above-described sensors and methods may be combined with additional temperature and power data obtained by the device to improve the accuracy of determining the hair moisture level.

[0184] Increases the moisture level of the hair

[0185] The use of the moisturizing product dispenser 29 to increase the moisture level of the hair (which may be formed, for example) will now be described in detail. Figure 3 The invention relates to a method and apparatus for moistening or re-moistening hair by heating the hair to reduce the moisture level. When controlling the moisture level of the hair to match the target moisture level is achieved by heating the hair to reduce the moisture level, the hair must have a moisture level higher than the target moisture level at the beginning of the heating process. Advantageously, when the device 10 is configured to increase the moisture level of the hair by dispensing fluid using the moisturizing product dispenser 29, the device 10 can increase the moisture level of the hair to above the target moisture level so that a subsequent heating process using the heater 25 will not cause the hair to become overly dry.

[0186] While the above method of controlling the moisture level of the hair may be used when the hair is already wet prior to using the device (e.g., when the user has washed their hair prior to using the device), the moistening product dispenser 29 may be used instead to moisten the hair (either prior to or as part of the styling process). Advantageously, more precise control of the initial moisture level of the hair may be achieved when the moistening product dispenser 29 is used to moisten the hair. Furthermore, more refined control of the moisture level may be achieved during and after the styling process. For example, if the heat transferred to the hair using the heater 25 has caused the hair to become drier than a target moisture level, this may be corrected by dispensing fluid onto the hair using the moistening product dispenser 29 (e.g., to restore the moisture level of the hair to the target moisture level).

[0187] The wet product dispenser 29 may be included in the fluid reservoir in the device 10. Water or any other suitable fluid may be dispensed on the hair from the fluid reservoir. The reservoir may be removed from the device 10 and / or may be refillable. The fluid dispensed from the wet product dispenser 29 may cause other beneficial effects except that the moisture level of the hair may be more accurately controlled. For example, the chemical composition used to enhance the styling performance may be used, such as being suitable for cleaning, coloring, enhancing styling, moisturizing / lubricating, repairing and / or protecting the fluid of hair. The wet product of lower viscosity may be preferred, because this enables to realize the more consistent distribution of fluid on whole hair. Advantageously, the example of the fluid distribution described below enables the device 10 to evenly distribute fluid between the hair strands of the user, while minimizing the user's potential suction or ingestion of the composition.

[0188] Vibration dispersion

[0189] The moistening product dispenser 29 may include a mechanical vibration element (e.g., a rope, cable, or vibrating rod) that operates at a certain frequency and amplitude for separating the individual fibers of the hair. Alternatively, the airflow produced by the fan 27 may be used to vibrate the hair. Advantageously, the vibration of the hair causes the liquid to be more evenly distributed throughout the hair. Even when the moistening product dispenser 29 does not add additional fluid to the hair, the vibration of the hair is also useful, for example, to achieve a more even distribution of the non-bound water present in the hair before using the device 10.

[0190] The vibrating element may be placed within the cavity of the device 10 so that the hair is clamped at either end of the cavity while remaining unrestrained in a central region of the cavity to be vibrated by the vibrating element. Alternatively, an airflow may be used to vibrate the hair within the cavity. The cavity may be at least partially sealed to reduce the risk of a user inhaling or ingesting the moistening product.

[0191] The moisturizing product dispenser 29 can be configured to vibrate the hair with any frequency and amplitude suitable for distributing fluid between the hairs. For example, a frequency between 10 Hz and 1 kHz can be used, and an amplitude between 0.5 mm and 10 mm can be used.

[0192] Piezoelectric transducer atomization

[0193] The moistening product dispenser 29 can be configured to disperse the moistening product (or any other suitable fluid) into the airflow using a piezoelectric transducer. Once atomized, the moistening product is delivered to the hair via the airflow generated by the fan 27 and deposited on the surface of the hair, thereby increasing the moisture level of the hair. The piezoelectric transducer can be placed directly against an internal moistening reservoir within the device 10, or can be configured to operate indirectly via an intermediate wick between the transducer and the reservoir.

[0194] Mechanical dispersion

[0195] The moisturizing product dispenser 29 can be configured to dispense the fluid onto the hair using a mechanical force driven by the user. For example, when the device 10 includes a pair of arms (e.g., Figure 1a12a, 12b of the device 10 shown in the figure, the opening and closing actions of the arms can be used to apply mechanical force to the internal reservoir of the fluid in the device 10, so that the fluid flows through the nozzle to wet the user's hair. Some energy from the user's movement of the device 10 can be stored in a compression spring or bellows for pumping fluid from the reservoir. When the spring is compressed, the increase in pressure can be used to make the fluid escape through one or more holes to wet the hair. Alternatively, an electric pump can be used to pump fluid through the holes. For example, the pump can be operated in response to an input from the user (e.g., pressing a button), or can be operated by a controller 36 of the device 10 (e.g., based on a determination of the current moisture level of the user's hair, and a determination that the moisture level should be increased).

[0196] Sacrificial Block

[0197] The moisturizing product dispenser 29 may include a sacrificial block material for controlling the moisture level of the hair. For example, the device 10 may use a fan 27 to generate an airflow on the sacrificial block, which causes the material to be transferred from the sacrificial block to the airflow (e.g., by sublimation). The material may then be transferred to the user's hair via the airflow to help control the moisture level of the hair. The sacrificial block may include any suitable material that helps control the moisture level of the user's hair. For example, the sacrificial block may include a chemical that helps regulate the amount of evaporation of bound or unbound water that occurs when the heater 25 is used to heat the hair.

[0198] Alternatively, a block of material may be provided that directly contacts the user's hair. For example, a sacrificial block of material may be provided Figure 1a On or near the heater plates 15a, 15b of the device shown in FIG.

[0199] Direct contact core

[0200] The fluid may be transferred from the reservoir to the hair contacting surface where it may then be used to increase the wetness level of the hair. For example, the moisturizing product dispenser 29 may include an internal reservoir of fluid that is transferred to the hair engaging surface via a wick, one end of the wick being immersed in the internal reservoir and the other end of the wick being coupled to the hair contacting surface to transfer the fluid. The hair contacting surface may be, for example, Figure 1a The heater plates 15a, 15b of the device are shown. However, it will be appreciated that the hair contacting surface may be any suitable surface of the device 10.

[0201] evaporation

[0202] The moisturizing product dispenser 29 can be configured to evaporate the fluid (e.g., by heating the fluid in the fluid reservoir) for subsequent delivery to the user's hair. The fluid can be evaporated into the airflow generated by the fan 27. The airflow comprising the evaporated fluid can then flow directly over the user's hair to increase the moisture level of the hair. The air comprising the evaporated fluid can flow into the pressurized cavity (which can also be referred to as a pressurized chamber) of the device 10 for subsequent delivery to the hair in the cavity.

[0203] Illustrative Example - Control Method

[0204] Fig. 9 A method of controlling the moisture level of a user's hair based on a target moisture level is shown. The method may be implemented using the controller 36 of the device 10.

[0205] In step S801, the device 10 receives a section of hair. Figure 1a In the type shown, a length of hair is received between heater plates 15a, 15b.

[0206] In step S802, a target moisture level of the hair is obtained. The target moisture level may be an ambient moisture level. The target moisture level may be obtained according to any method for obtaining the above target moisture level.

[0207] In step S803, the current moisture level of the hair is obtained. The current moisture level may be obtained (eg measured) according to any of the above methods for obtaining the current moisture level of the hair.

[0208] In step S804, the device 10 transfers heat to the section of hair using the heater 25. For example, the heat may be transferred to the hair via conduction using the heater plate 15, and / or may be transferred using a heated air flow generated by the heater 25 and the fan 27, and / or using any other suitable method (including any of the methods described above).

[0209] The operating temperature for heating the hair in step S804 (e.g., the temperature of the heater plate 15, or the temperature of the heated air generated by the device 10) may be determined by the controller 36 based on the current humidity level obtained in step S803 and the target humidity level obtained in step S802. For example, the controller 36 may be configured to control the operating temperature based on the difference between the current humidity level and the target humidity level. The controller 36 may be configured to use an equation stored in the memory 63 or to use a lookup table stored in the memory 63 (such as the one described above with reference to FIG. 1 ). Figure 6The operating temperature is controlled based on the difference between the current moisture level and the target moisture level using the table described above. Advantageously, this allows the heat delivered to the hair to be reduced as the hair approaches the target moisture level, thereby reducing the risk of "overshooting" and over-drying the hair.

[0210] For example, when the device 10 includes a heater plate 15 for transferring heat to the hair, the controller 36 can be configured to control the temperature of the heater plate 15 based on the amount of moisture detected (using the humidity sensor 64) above the target moisture level. When the hair has a large amount of excess water (e.g., the hair is visibly wet and has a large amount of unbound water), an operating temperature of less than or equal to 120° C. can be used to prevent "sizzling" (as described in detail above). When the hair has a moderate amount of excess water, a temperature between 120° C. and 200° C. can be used to obtain more effective drying and styling performance. When there is a small amount of excess water, the operating temperature can be directly controlled based on the amount of excess water. In other words, the amount of heat transferred to the hair can be used as a function of the amount of excess water. c -M t ) function to control, where M c is the current moisture level of the hair, and M t is the target moisture level of the hair. c -M t ) approaches zero, the heat transferred to the hair by the device 10 also approaches zero. c -M t =0), or when the difference between the target humidity level and the current humidity level is within a threshold range, the operating temperature may be controlled to the lowest possible operating temperature. The lowest temperature may be ambient room temperature. However, if the device is required to respond quickly enough for the user to start drying and / or styling the next section of hair, the lowest temperature may be above ambient temperature. Advantageously, when thick film printed heaters or radiant heaters are used to transfer heat to the hair, the minimum heat transfer is reduced due to the fast temperature response of these types of heaters, and the risk of over-drying the hair is correspondingly reduced.

[0211] Step S804 may also include applying controlled tension to the hair using the device 10 while the hair is being heated and / or styled. For example, the hair may be held in place at two points on either side of the cavity, and heat may be transferred to the hair in the cavity (e.g., by using a heated air stream generated by the device 10). Advantageously, by applying tension to the hair while the hair is being heated and / or styled (e.g., by securing the hair between two points), undesirable crossing and tangling of hair fibers is reduced, thereby enabling increased fiber alignment, and providing improved shine and improved smoothness.

[0212] In step S805, the current moisture level of the hair segment is retrieved.The current moisture level may be obtained (eg measured) according to any of the methods described in detail above for obtaining the current moisture level of the hair.

[0213] In step S806, the controller 36 determines whether the current moisture level of the hair section is lower than or equal to the target moisture level. If the result of the determination in step S806 is "no", the method returns to step S804, in which the hair is further heated to further reduce the moisture level of the hair.

[0214] If the result of the determination in step S806 is "yes", the controller 36 can be configured to quickly prevent any further heat transfer to the hair. For example, power to the air heater can be deactivated, the radiant heater can be immediately turned off, and the conductive heater (e.g., a thick film printed heater with a particularly low thermal mass) can be turned off and allowed to cool quickly. Advantageously, this prevents excessive drying of the hair caused by heat transfer after it has been determined that the hair is at or below the target moisture level.

[0215] The device 10 can also be configured to use ambient airflow (e.g., using fan 27) to quickly cool the hair to ambient temperature to prevent over-drying of the hair. In addition, once the style has been imparted, lowering the temperature of the hair advantageously causes the hair to transition to a more glassy and less plasticized state, which enables the hair section to better resist any adverse stresses applied to the hair.

[0216] If the determination result in step S806 is "yes", the method may proceed to optional step S807. Alternatively, the method may simply proceed to step S808 to complete the method. Optionally, if the user begins drying / styling the next lock of hair, the method may return from step S808 to S801.

[0217] In optional step S807, the device 10 increases the moisture level of the hair using the moisturizing product dispenser 29. For example, step S807 may be used when the current moisture level of the hair is significantly below the target moisture level and should be re-moistened. The current moisture level may be increased according to any of the methods described in detail above for increasing the current moisture level of the hair. The method then returns to step S803.

[0218] Fig.10 Shows Fig. 9A variation of the flowchart of , including an additional step S806b. In step S806b, the user indicates via the user interface 11 whether the user is satisfied with the hair styling / drying result. The user may enter the indication via any suitable element of the user interface 11 or via the communication circuit 67 (e.g., using a smartphone application connected to the device 10 via the communication circuit 67). If the user is not satisfied with the drying / styling result, the method proceeds to step S807, in which the hair is re-wetted using the moisturizing product dispenser 29 and the heating / styling process is restarted. If the user is satisfied with the styling / drying result, the method proceeds to step S808.

[0219] The device 10 may be configured to update one or more operating profiles stored in the memory 63 based on the feedback received from the user in step S806b. Advantageously, this enables the device 10 to modify the styling process for different types of hair (because the optimal operating parameters for styling / drying may depend on, for example, the thickness of the user's hair) or to modify the styling process based on the specific styling technique used by the user to achieve a more durable hairstyle and improve the overall efficiency of the device 10. For example, the device 10 may be configured to change the operating temperature or heating duration based on the feedback received from the user. The target moisture level may also be adjusted based on the feedback received in step S806b. The feedback received from the user is not necessarily a simple yes / no response. For example, the feedback may include a rating on a numerical scale, or may include additional information, such as feedback on the texture or feel of the styled hair. The device 10 may be configured to output a delayed query to the user. For example, a predetermined amount of time after completing the styling process, the device 10 may be configured to output a query to the user regarding the durability of the hairstyle (e.g., a query regarding how much of the hairstyle still exists). User feedback input in response to the delayed query may be used to train device 10 (e.g., update stored operating parameters) to produce more durable hairstyles, or may be used to output personalized product recommendations (e.g., moisturizing product recommendations) or styling tips to the user.

[0220] Other embodiments

[0221] Fig.11a is a perspective view of a combined hair drying / styling device 110 according to another embodiment (which may or may not employ the moisture detection technology described above), wherein arms 114, 116 are in an open configuration, and Fig.11b The arms 114, 116 are shown closed (as in use, e.g. Fig.11c The same device 110 as shown). Figure 12 to Figure 14 further views of components of the device 110 are shown, and Fig.13 and Fig.14The airflow through the device 110 in use is shown.

[0222] First reference Fig.11a and Fig.11b , device 110 is an all-in-one handheld device that can be used to dry hair in a quick and easy manner while also being able to style the hair (e.g., straighten the hair, or add "body and volume" to the hair).

[0223] The device 110 includes a first arm 114 and a second arm 116 that are arranged in a manner generally similar to the arms of a handheld hair styling tool. The first arm 114 has a main body portion 112 at a proximal end 192 of the arm 114 and a distal end 193 for treating hair. The second arm 116 is coupled to the first arm 114 at its proximal end 194 and has a distal end 195 for treating hair. The first arm 114 and the second arm 116 are adapted to be in an open configuration (e.g., Fig.11a ) and closed configuration (as shown Fig.11b 114, 116 are movable between the arms 114 and 116, wherein in the open configuration, the first arm and the second arm receive the wet hair segment between them, and in the closed configuration, the first arm and the second arm are adjacent to the hair to generate tension in the hair, so that in use, when the arms 114 and 116 are in the closed configuration, the arms 114 and 116 form a pressurized chamber (113, Fig.14 ), the hair passes through the pressurized chamber.

[0224] Fig.12 1 is a perspective view of the main body portion 112 of the lower arm 14 with half of the housing removed to reveal the major components mounted within the main body portion 112. Fig.12 As shown, the main body 112 accommodates a fan assembly 138 at its proximal end 92 for sucking air (indicated by arrow 173) into the main body 112 through an air inlet 160, and for forcing the air along the main body 112 toward the distal hair treatment end of the lower arm 114. The air inlet 160 is formed as an annular opening around a spigot 163 (shown in FIG. 11 ), which extends beyond the proximal end 192 of the main body 112. Therefore, the spigot 163 makes it difficult for an object to close the entire air inlet 160. In addition, the proximal end 192 of the main body 112 is also preferably inclined relative to the longitudinal axis of the main body 112, because this also helps to reduce the possibility of the entire air inlet 160 being blocked. The fan assembly 138 has an impeller and is generally also provided with a filter 165 to prevent dust and debris from reaching the fan assembly 138.

[0225] Air from the fan assembly 138 is heated by the heater 130 before being directed to the distal end 193 of the lower arm 114 where the airflow directing structure 124 (at Fig.13) directs air toward the user's hair. More specifically, as shown in more detail in the cross-sectional view of Fig.13 As shown, heated air from the heater 130 passes along the distal end 193 of the lower arm 114 in a direction D1 substantially parallel to the length of the arm 114, and the airflow guide structure 124 redirects the air to a second direction D2, i.e., from the arm 114 toward the opposite arm 116, i.e., inwardly into the inter-arm plenum chamber 113 formed by the arms 114, 116 in the closed position (e.g., Fig.14 The heater 130 typically takes the form of an electrically powered heating coil (or other electrical heating element) that is operable to heat air drawn in by the fan assembly 138 .

[0226] like Fig.12 As shown in the circuit board 136 in FIG. 1 , the control electronics 137 are mounted within the body portion 112 between the fan assembly 138 and the heater 130. This allows incoming air to keep the control electronics 137 cool during use. Electrical power is provided to the device 110 via a power cord 164 which is typically connected to an AC mains power source. However, in alternative embodiments, the device 110 may be powered by one or more DC batteries or battery cells (which may be rechargeable, for example from a mains or DC power source via a charging lead), thereby enabling the device 110 to be a cordless product. The control electronics 137 controls the operation of the device 110. As shown in FIG. Fig.11a As shown, a control button or switch 123 can be provided on the device 110 to enable the device to be turned on or off, and the control electronics 137 can control the on and off of the indicator light to indicate whether the power is on. The control electronics 137 can also cause a sound generator (not shown) to emit a sound when the device 110 is turned on and ready for use.

[0227] For example Fig.11a As shown, the second arm 116 is coupled to the main body 112 of the first arm 114 by a hinge 118, by which the first arm 114 and the second arm 116 can move relative to each other (in the illustrated embodiment, by moving the second arm 116 toward and away from the first arm 114). Thus, in use, the first arm 114 and the second arm 116 can be brought together by a user into a closed configuration (such as Fig.11b ), or move them apart and enter the open configuration (as shown Fig.11a In the illustrated embodiment, each of the arms 114, 116 widens relative to the main body portion 112 to form a "head" of the device 110 that is distal from the main body portion 112, although other embodiments are possible where the head does not widen in the manner shown.

[0228] The hinge 118 may incorporate any suitable mechanism to allow the first arm 114 and the second arm 116 to move relative to each other. Preferably, the hinge 118 also incorporates a spring mechanism that is configured to bias the first arm 114 and the second arm 116 to an open configuration, such that a user needs to apply pressure to the arms 114, 116 to close them together (overcoming the action of the spring mechanism), and such that once the pressure is removed, the arms 114, 116 automatically open under the action of the spring mechanism. For example, the hinge 118 may incorporate a leaf spring or a coil spring.

[0229] The hinge 118 and the spring mechanism may be one and the same. For example, the spring mechanism itself may be used to couple the second arm 116 to the body portion 112, thereby avoiding the need for a separate mechanical hinge and simplifying the overall construction of the device 110.

[0230] like Fig.11a As shown, in the illustrated embodiment, the inner surface of the first arm 114 incorporates a first elongated heater plate 120a and a second elongated heater plate 120b, which extend along the length of the arm 114 on both sides of the airflow guide structure 124. The second arm 116 also incorporates a first elongated heater plate 122a and a second elongated heater plate 122b (at positions corresponding to the heater plates 120a and 120b) Fig.11a is not visible in , but for example in Fig.14 1 ). Each of the heater plates 120a, 120b, 122a, 122b is provided with a respective electric heating element operable to heat the respective heater plate. In the illustrated embodiment, the operating temperature of the heater plates 120a, 120b, 122a, 122b is typically about 120°C to 130°C.

[0231] The first and second arms 114, 116 and the first and second heater plates 120a, 120b, 122a, 122b on each arm are arranged so that when the arms 114, 116 are in the closed configuration, the first and second heater plates 120a, 120b of the first arm 114 are in contact with the first and second heater plates 122a, 122b of the second arm 116. Preferably, the heater plates 120a, 120b, 122a, 122b are made of a material having a relatively high thermal conductivity, and are preferably provided with one or more temperature sensors for sensing the temperature of the heater plates (e.g., a temperature sensor for each plate, or one or more temperature sensors each serving a plurality of heater plates). The sensed temperature is then fed back to the control electronics 137 so that the control electronics 37 can control the power delivered to the heater plates 120a, 120b, 122a, 122b to maintain the heater plates at a desired operating temperature.

[0232] The heater plates 120a, 120b, 122a, 122b serve multiple purposes during use of the device 110. First, once a user has sandwiched a length of wet hair between the opposing plates 120a and 122a and between the opposing plates 120b and 122b (i.e., laterally across the plenum chamber 113 formed by the first arm 114 and the second arm 116 in the closed configuration) and by pulling the device 110 along the length of the wet hair, the heater plates 120a, 120b, 122a, 122b subject the wet hair to a scraping action, thereby removing excess unbound water, and also heating the hair to promote subsequent evaporation of the water. Second, the heating provided by the heater plates 120a, 120b, 122a, 122b causes the walls of the plenum chamber 113 to be heated (via thermal conduction), and also helps maintain the temperature of the airflow delivered through the plenum chamber 113 by the fan assembly 138. Third, as an integral part of the drying process, the heater plates 120a, 120b, 122a, 122b can be used to style the hair. The heater plates 120a, 120b, 122a, 122b are preferably configured as ceramic floating plates with a low spring rate or stiffness spring to provide good control of hair tension.

[0233] Taking into account the airflow heating coil (or other heating element) and the heater plates 120a, 120b, 122a, 122b, and the fan assembly 138, the overall power consumption of the device 110 is about 600 W to 800 W, which is significantly less than a conventional hair dryer of 2000 W. Of course, a higher power motor can be used in the device 10, which will increase the power consumption, but will allow the device 110 to dry the user's hair faster.

[0234] Now turn to Fig.14, which shows an additional direction of airflow through the arms 114 , 116 of the device 110 when viewed in cross-section, which faces the main body 112 of the device 110 .

[0235] from Fig.14 Starting at the center of the device 110, it can be seen that air flowing from the lower arm 114 in direction D2 enters the inter-arm plenum chamber 113 from the airflow duct 115 via the unit of the airflow guide structure 124. Some of the air will bounce off the user's hair, while some of the air will enter the other arm 116. Upon leaving the inter-arm chamber 113, the air spreads laterally and enters the airflow redirection channel 128, from which it then passes along the airflow ducts 119a, 119b, 121a and 121b to exit the device 110 via the vent 126 in directions D3 (via ducts 119a and 121a) and D4 (via ducts 119b and 121b). Fig.14 As shown, airflow ducts 119a, 119b, 121a and 121b extend behind heater plates 120a, 120b, 122a and 122b mounted on first arm 114 and second arm 116, respectively. Advantageously, vents 126 direct outflowing air toward the roots of the hair to dry the roots and create root lift.

[0236] It has been found that the above-described device 110 can provide effective drying and styling of the user's hair. The combination of conductive heating of the hair by the heater plates 120a, 120b, 122a and 122b and convective heating of the hair within the enclosed chamber 113 by the heated air flow significantly improves the drying efficiency of the device 110 compared to conventional hot air devices.

[0237] The inventors have made a number of improvements to the above-described apparatus 10 which will now be described below.

[0238] One improvement involves using diffusers at the vents 126 of the arms 114, 116. These diffusers can help reduce flying away problems caused by having a concentrated airflow from the vents 126, and can also help cool the user's hair as it leaves the device 110, which helps with styling.

[0239] Fig.15 is a transverse cross-sectional view of the device 110 having four diffusers 140a, 140b, 142a, 142b mounted in the air flow ducts 119a, 119b, 121a and 121b ( Fig.1414 and 142). In the embodiment of the present invention, the air flow conduits extend behind the heater plates 120a, 120b, 122a and 122b mounted on the first arm 114 and the second arm 116, respectively. As schematically shown, the air leaving the device is diffused in a variety of different directions (shown by the arrows leaving the diffusers 140, 142 in different directions), rather than just in directions D3 and D4 as before. This helps prevent the exhaust air leaving the device 110 from causing the hair to drift away from the device when styling a section of hair, and ultimately reduces the possibility of "flutter" in the final styled hair. "Flutter" or "frizz" is a term in the field of hair styling, which refers to hair that is not aligned with the surrounding hair, but stands up or curls independently, thereby producing (usually) undesirable messy or irregular textured hair. Additionally, if the diffusers 140, 142 are made of a thermally conductive material (e.g., copper or aluminum or ceramic), the hair that contacts the housing of the device 110 as the hair leaves the device 110 will be cooled by conduction and convection cooling, which helps to set the style that the user has achieved. In particular, as the heated air exits through the diffusers 140, 142, the heated air will lose most of its heat to the hair and evaporate water from the hair. Thus, the air exiting the diffusers will be cool enough to set the hairstyle that the user creates using the device 110, whether it is straight or curly (this is typically achieved by turning the device during use so that the hair is forced to change direction as it leaves the device 110, which creates curls).

[0240] Of course, Figures 11 to Fig.15 The device shown in is designed to be symmetrical so that it can be used in the left or right hand. In the case where the device is intended for a single direction of use, only two diffusers 140, 142 can be provided on the hair outlet side of the device 110. Fig.15 In the arrangement shown, air is supplied down one of the two arms 114, 116. As will be appreciated by those skilled in the art, if desired, air may be supplied down both arms 114, 116 and fed together in opposite directions into a central plenum chamber 113 formed between the two arms 114, 116.

[0241] Another improvement involves providing a "quench" actuator switch or sensing mechanism 129 (e.g., Fig.16). It is known in the art that in order to (quickly) reshape the hair, heat is needed to help plasticize the hair, and mechanical stress is needed in the direction in which the hair is to be deformed / reshaped / styled. Once heated, the hair exists in a more plastic state and can be easily reshaped, so it is counterproductive to apply damaging mechanical forces in any direction other than the desired styling direction while the hair remains hot and pliable. This includes, for example, gravity acting to extend the curls when they are removed from any styling device, or tensioning the hair into straight hair after curling with a styling device. If the hair can be cooled before any damaging forces (forces in undesirable directions) are applied, the bonds within the hair can be set and less likely to be repositioned by the damaging forces. This action can be referred to as "quenching", and can improve hair styling performance by a hair styling device, for example, tighter curls or straighter straightened hair, and reduced flyaways / curls.

[0242] In the prior art, quenching has not been provided within a single combined hair drying / styling device. The inventors have recognized that in any such device, as set forth in this application, a simple switch (not shown) or sensor relaying the sensed activity to a control system can be used to shut off the heating of the airflow while leaving the conductive hair heating on, and this provides the user with the novel ability to simply "press a button" (or equivalent action) to have the ability to quench a hairstyle they have created, thereby achieving a hairstyle effect that is superior to that of prior art devices. In some embodiments, the "quenching" activator switch or sensing mechanism 129 can be combined with a "cold shock" switch or sensing mechanism (not shown) for activating a separate "cold shock" mode as previously described.

[0243] Another improvement that the inventor has made is to control the speed of the fan of fan assembly 138. In particular, the inventor has found that when the user of the two-arm device opens arms 114, 116 to place the wet hair section to be dried between the arms, the airflow from fan assembly 138 makes it more difficult for the user to insert the hair section between the two arms without causing the hair to float from the device. The inventor has found that this problem can be alleviated by changing the speed of fan assembly 138 according to the open / closed state of arms 114, 116. More specifically, the inventor has found that changing the airflow speed between the first airflow speed when arms 114, 116 are in the open configuration and the second airflow speed when arms 114, 116 are in the closed configuration (it is higher than the first airflow speed) helps to alleviate the above-mentioned problem. The change of airflow speed can be a step change (for example, between opening (on) and closing (off) or between two set airflow speeds), or can be a stepwise change or a smooth change between the first airflow speed and the second airflow speed. Fig.161 is a block diagram showing the main control components of the hair drying and styling device 110 that can achieve this improvement. As shown in the figure, the control circuit is very similar to the above Figure 1c , except that it has an open / closed sensor 127 for sensing the state of the arms 114, 116. This can be a simple binary sensor (such as a microswitch or an optical sensor) that detects whether the arms 114, 116 are open or closed, and the microprocessor 62 uses this information to control the speed of the fan assembly 138 in the manner described above. In a more complex arrangement, the open / closed sensor 127 can sense different degrees of opening of the arms 114, 116. This can be achieved, for example, using a potentiometer whose resistance gradually changes as the arms are opened and closed, or a position sensor that senses the hinge 118 between the open and closed states. In this case, the microprocessor 62 can perform more complex airflow speed changes rather than a simple switch between two airflow speeds. In addition to reducing the airflow speed of the fan assembly 138, the microprocessor 62 also preferably reduces the heat generated by the air heater 130 so that the air heater 130 does not overheat and / or the temperature of the airflow at the lower airflow speed is not too hot for the user. In other embodiments (not shown), particularly in combined drying / styling devices having only a single arm, such as in the general form of a curling iron but with air ducts therein, such as disclosed in US 6,363,215, the speed of a fan (not shown) is controlled in response to at least one other triggering mechanism (such as an accelerometer, gyroscope, micro switch or the like (not shown)) sensing the operating configuration of the device, providing a more significant device safety advantage in terms of being able to avoid surface damage to any surface (such as a tabletop or scalp) that the device may be close enough to potentially cause such surface damage, or providing varying fan speeds in different situations (e.g. providing a faster fan speed when hair is sensed to have become entangled in such a hair-drying curling iron, or providing a faster fan speed when hair is sensed to be present between the arms of a two-arm combined drying / styling device).

[0244] Variations and substitutions

[0245] Detailed embodiments and some possible substitutions have been described above. As will be appreciated by those skilled in the art, many variations and further substitutions may be made to the above embodiments while still benefiting from the invention embodied in the embodiments. Therefore, it should be understood that the present invention is not limited to the described embodiments and includes variations that are obvious to those skilled in the art and fall within the scope of the appended claims.

[0246] The device 10 may be partially or completely formed from a unitary structure, such as by 3D printing.

[0247] In the above examples, the device 10 may include a single heater 25, or may include two or more heaters 25. More generally, the device 10 may include any suitable means for transferring heat to the user's hair, such as any suitable conduction heater, thick film printed heater, steam heater, or radiant heater.

[0248] In some of the above examples, the device 10 need not necessarily include a humidity sensor 64 for sensing hair moisture. Alternatively, for example, the device 10 may be configured to heat the hair using a predetermined set of operating parameters based on a target moisture level. For example, a table of target moisture levels and corresponding operating temperatures required to achieve the target moisture levels may be predetermined and stored in the memory 63. In such a configuration, the device 10 need only identify the operating temperature to be used (and any other relevant operating parameters) from the table, and need not sense the moisture of the hair. However, providing a humidity sensor 64 for sensing hair moisture is still beneficial for verifying that the hair has reached the desired moisture level, and enables more precise control of the moisture level.

[0249] In some of the above examples, the device 10 has been described as increasing the moisture level of the user's hair before the hair is heated by the device to reduce the moisture level (for example, by distributing fluid to the hair). However, the device 10 may also (or alternatively) be configured to distribute fluid to the hair during and / or after heating the hair. For example, a fluid (for example a surfactant) that does not need to be dispersed in the hair may be distributed to the hair during the heating process. The wetting product may also be used to increase the drying rate of the hair (i.e., the rate at which the moisture level of the hair is reduced). The wetting product may include a surfactant (wetting agent), which increases the drying rate of the hair by reducing the surface tension of water on the hair. The wetting product may include a desiccant, which reduces the moisture level of the hair by absorbing water from the hair. The wetting product may include one or more azeotropic mixtures, which increase the drying rate of the hair by reducing the boiling point of water on the hair. The wetting product may include one or more impurities, which increase the drying rate of the hair by increasing the number of positions on the hair where water boiling can occur.

[0250] Throughout the description and claims of this specification, the words "include" and "comprises" 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.

[0251] Figure 1aThe device shown uses a plate commonly used to straighten the user's hair. In other embodiments, the device may use other types of heaters. For example, instead of having a heater plate, a ribbed heater may be used to curl the hair during the styling process. Similarly, the heating surface may be defined by a cylindrical heater commonly used in curling irons.

[0252] Various other variations will be apparent to those skilled in the art and are not described in further detail here.

Claims

1. A device for drying or styling hair, the device comprising: a heating mechanism for heating the hair to reduce the moisture level of the hair; as well as A controller is configured to control the device to take action for controlling the moisture level of the hair based on a target moisture level.

2. The device according to claim 1, wherein The controller is configured to control the moisture level of the hair to be within a threshold range of the target moisture level.

3. The device according to claim 1 or 2, wherein: The target humidity level corresponds to the ambient humidity level.

4. The device according to any one of the preceding claims, wherein: The controller is configured to control an operating parameter of the heating mechanism based on the target moisture level to control the moisture level of the hair.

5. Apparatus according to any one of the preceding claims, wherein: The controller is configured to control the heating mechanism to reduce a difference between the moisture level of the hair and the target moisture level.

6. The device according to claim 5, wherein: The controller is configured to control the heating mechanism to reduce a heat output or an operating temperature of the heating mechanism when the humidity level approaches the target humidity level.

7. Apparatus according to any one of the preceding claims, wherein: The device comprises a memory configured to store a plurality of operating parameters of the device; and The device is configured to identify, from a stored plurality of operating parameters, an operating parameter to be used to control the moisture level of the hair towards the target moisture level, based on the moisture level of the hair or based on the target moisture level of the hair.

8. The device according to claim 7, wherein: The operating parameters include at least one of operating temperature and heat output.

9. The device according to any one of the preceding claims, in, The apparatus further comprises at least one sensor for outputting a sensor output that varies with the moisture level of the hair; and Therein, the device is configured to determine the moisture level of the hair based on the sensor output.

10. The device according to any one of the preceding claims, in, The device comprises a temperature sensor for sensing the temperature of the hair; and Therein, the device is configured to determine the moisture level of the hair based on the sensed temperature of the hair.

11. The device according to claim 10, wherein: The device is configured to determine the moisture level of the hair based on a measured change in temperature of the hair over time.

12. The device according to any one of the preceding claims, in, The heating mechanism comprises a heatable surface for transferring heat to the hair; wherein the apparatus comprises a temperature sensor for sensing the temperature of the heatable surface; and Therein, the device is configured to determine the moisture level of the hair based on the temperature of the heatable surface.

13. The apparatus according to any one of claims 10 to 12, wherein: The temperature sensor includes at least one of a thermistor, a thermocouple and an infrared radiation sensor.

14. Apparatus according to any one of the preceding claims, wherein: The apparatus also includes means for achieving the target moisture level.

15. The apparatus of claim 14, wherein: The target humidity level is the ambient humidity level; wherein the device comprises a sensor for outputting a sensor output that varies with the humidity of the environment; and Wherein the device is configured to use the sensor output to determine the ambient humidity level.

16. The device according to claim 15, wherein: The sensor for outputting the sensor output that varies with the ambient humidity includes a hygrometer.

17. Apparatus according to any one of the preceding claims, in, The device comprises a capacitive sensor for outputting a sensor output that varies with a current moisture level of the hair; and Therein, the device is configured to determine the current moisture level of the hair using the sensor output from the capacitive sensor as a function of the current moisture level of the hair.

18. The device according to claim 17, in, The device is configured to generate an airflow across or through the hair, And wherein the capacitive sensor is configured to sense the humidity level of air that has passed across or through the hair.

19. Apparatus according to any one of the preceding claims, in, The device comprises an optical sensor; and Therein, the device is configured to determine the moisture level of the hair based on a light intensity of light passing through the hair measured by the optical sensor, based on a light intensity of light reflected from the hair and / or based on a light intensity of light passing through air near the hair.

20. The apparatus of claim 19, wherein: The device also includes a light source for emitting light that passes through the hair, reflects from the hair, and / or passes through the air near the hair.

21. The apparatus according to claim 19 or 20, wherein: The optical sensor is configured to sense an intensity of light indicative of a fluid or a moistening product to determine an amount of the fluid or moistening product in the hair.

22. Apparatus according to any one of the preceding claims, in, The device comprises a sensor for measuring electrical resistance that varies with a current level of moisture of the hair; and Therein, the device is configured to determine the moisture level of the hair based on the measured electrical resistance.

23. The apparatus of claim 22, wherein: The sensor for measuring the electrical resistance comprises a hygroscopic conductive layer.

24. Apparatus according to any one of the preceding claims, in, The device is configured to apply an electric field to the hair; wherein the device is configured to measure at least one dielectric property of the hair using the applied electric field; and Therein, the device is configured to determine the moisture level of the hair based on the measured dielectric property.

25. Apparatus according to any preceding claim, wherein: The apparatus further comprises means for producing an indication to a user that the moisture level of the hair is within a threshold range of the target moisture level.

26. Apparatus according to any preceding claim, wherein: The controller is configured to control the device to control the moisture level of the hair by outputting an indication of the current moisture level of the hair to a user.

27. The apparatus of claim 26, wherein: The controller is configured to control the device to control the moisture level of the hair by outputting to a user an indication of the current moisture level of the hair relative to the target moisture level.

28. Apparatus according to any preceding claim, wherein: The device is configured to output an indication to the user of instructions for operating the device, and The device is configured to determine the instructions to output based on the moisture level of the hair or based on the target moisture level.

29. Apparatus according to any one of the preceding claims, in, The device includes a user interface; Wherein the user interface is operable by a user to input an indication of the target humidity level.

30. Apparatus according to any preceding claim, wherein: The device further comprises a fluid dispenser for increasing the wetness level of the hair by dispensing fluid onto the hair.

31. The apparatus of claim 30, wherein: The controller is configured to control the device to increase the moisture level of the hair using the fluid dispenser prior to heating the hair using the heating mechanism.

32. Apparatus according to claim 30 or 31, wherein: The device is configured to vibrate the hair to disperse the fluid in the hair.

33. The apparatus of claim 32, wherein: The device comprises a vibrating member for vibrating the hairs.

34. Apparatus according to claim 32 or 33, wherein: The device is configured to generate an air flow to cause the hairs to vibrate.

35. Apparatus according to any preceding claim, wherein: The device is a hair straightener, a hair dryer, a heated paddle brush, a heated round brush, heated rollers or a curling iron.

36. Apparatus according to any preceding claim, wherein: The target moisture level is preconfigured and stored in the device.

37. Apparatus according to any preceding claim, wherein: The apparatus is configured to receive the target moisture level from a separate device.

38. The apparatus of claim 37, wherein: The device is configured to receive a target moisture level that has been input by a user into a smartphone application.

39. An apparatus for drying or styling hair, the apparatus comprising: a heating mechanism for heating the hair to reduce the moisture level of the hair; a sensor for outputting a sensor output that varies with a current moisture level of the hair; as well as A controller, the controller being configured to: i) determining the current moisture level of the hair using the sensor output; and ii) outputting an indication to the user which is dependent on the determined current moisture level of said hair.

40. The apparatus of claim 39, wherein: The indication is an indication of the current moisture level of the hair.

41. The apparatus according to claim 39, in, The apparatus is configured to achieve a target moisture level of the hair; and Wherein the indication is an indication of a difference between the target moisture level of the hair and the determined current moisture level of the hair.

42. The apparatus of claim 41, wherein: The target humidity level corresponds to the ambient humidity level.

43. Apparatus according to any one of claims 39 to 42, wherein: The indication includes at least one of a visual indication, an auditory indication, and a tactile indication.

44. Apparatus according to any one of claims 41 to 43, wherein: The apparatus is configured to receive the target moisture level from a separate device.

45. The apparatus of claim 44, wherein: The device is configured to receive a target moisture level that has been input by a user into a smartphone application.

46. ​​Apparatus according to any preceding claim, wherein: The heating mechanism is configured to generate steam; and Wherein, the device is configured to use the steam to reduce the moisture level of the hair.

47. An apparatus for drying or styling hair, the apparatus comprising: A heating mechanism, the heating mechanism being used to generate steam; Wherein the device is configured to use the steam to reduce the moisture level of the hair.

48. The apparatus of claim 47, wherein: The heating mechanism is configured to heat the recirculating steam that has been used to reduce the moisture level of the hair; and Wherein said apparatus is configured to use said recirculating steam to reduce said moisture level of said hair.

49. Apparatus according to claim 47 or 48, wherein: The apparatus comprises a heat exchanger for recovering heat from steam that has been used to reduce the moisture level of the hair.

50. Apparatus according to any one of claims 47 to 49, wherein The apparatus is configured to heat the steam to superheat it before the steam is used to reduce the moisture level of the hair.

51. Apparatus according to any one of claims 47 to 50, wherein: The device comprises a controller configured to control the device based on a target moisture level to reduce the moisture level of the hair using the steam.

52. The apparatus of claim 51, wherein: The controller is configured to control the moisture level of the hair to be within a threshold range of the target moisture level.

53. Apparatus according to claim 51 or 52, wherein: The target humidity level corresponds to the ambient humidity level.

54. Apparatus according to any one of claims 51 to 53, wherein: The controller is configured to control the device to use the steam to reduce a difference between the moisture level of the hair and the target moisture level.

55. A method for drying or styling hair, the method comprising: heating the hair to reduce the moisture level of said hair; as well as The moisture level of the hair is controlled based on a target moisture level.

56. A method for drying or styling hair, the method comprising: heating the hair to reduce the moisture level of said hair; as well as An indication of the current moisture level of the hair is output to the user.

57. A method for drying or styling hair, the method comprising: heating the hair to reduce the moisture level of said hair; obtaining a target moisture level of the hair and a current moisture level of the hair; as well as An indication of a difference between the target moisture level of the hair and the current moisture level of the hair is output to a user.

58. A device for drying or styling hair, comprising: a first and second arm disposed opposite one another, the first and second arms being adapted to move between an open configuration in which the first and second arms receive wet hair segments therebetween, and a closed configuration in which the first and second arms are adjacent the hair, such that in use, when the first and second arms are in the closed configuration, the first and second arms form an inter-arm chamber through which the hair passes in use, and wherein an airflow conduit is disposed within and along at least one of the first and second arms of the device; a conveying mechanism for conveying a gas flow along the conduit in the at least one of the first arm and the second arm and subsequently conveying the gas flow into the inter-arm chamber; a sensor for sensing whether the first arm and the second arm are in the open configuration or the closed configuration; as well as A control mechanism is used to control the conveying mechanism to change the airflow depending on whether the first arm and the second arm are in the open configuration or the closed configuration.

59. The apparatus of claim 58, wherein: The control mechanism is configured to cause the conveying mechanism to provide a first air flow rate when the first arm and the second arm are in the open configuration, and to provide a second air flow rate greater than the first air flow rate when the first arm and the second arm are in the closed configuration.

60. The apparatus of claim 59, wherein: The control mechanism is configured to cause the delivery mechanism to vary the gas flow between the first flow rate and the second flow rate in a step-wise variation or in a smoothly varying manner.

61. A device for drying or styling hair, comprising: an airflow conduit within and along at least one first arm of the device; a conveying mechanism, the conveying mechanism conveying the airflow along the conduit; a conduction heater for heating the hair by conduction; a sensor for sensing an operating mode of the device; and A control mechanism controls the delivery mechanism to change the airflow according to the output of the sensor.

62. The device according to claim 61, wherein The sensor is selected from the group consisting of an accelerometer, a gyroscope, and a switch; and wherein The sensed operational modality is whether the device is currently in motion, or whether the device is currently in a specified orientation, or whether the device is currently near or on a surface.

63. A device for drying or styling hair, comprising: a first arm and a second arm disposed opposite each other, the first arm and the second arm being adapted to move between an open configuration in which the first arm and the second arm receive wet hair segments therebetween, and a closed configuration in which the first arm and the second arm are adjacent to the hair, such that in use, when the first arm and the second arm are in the closed configuration, the first arm and the second arm form an inter-arm chamber through which the hair passes in use, and wherein the airflow conduit is disposed in and along at least one of the first arm and the second arm; a conveying mechanism for conveying a gas flow along the conduit in the at least one of the first arm and the second arm and subsequently conveying the gas flow into the inter-arm chamber; at least one vent through which air from the inter-arm chamber can exit the device; as well as An air diffuser is mounted between the vent and the inter-arm chamber to diffuse air exiting the device.

64. The apparatus of claim 63, wherein: The air diffuser includes a thermally conductive material.

65. The apparatus of claim 64, wherein: The air diffuser is positioned adjacent the outlet through which dried and styled hair exits the device to provide conductive and convective cooling of the hair as it exits the device, thereby setting the hairstyle produced by the device.

66. The device according to any one of claims 58 to 65 further comprises mutually opposing hair contact members arranged on the first arm and the second arm, the mutually opposing hair contact members being arranged to come together when the first arm and the second arm are in the closed configuration, and preferably, at least one of the hair contact members comprises a conductive heater.

67. The apparatus of any one of claims 58 to 66, comprising: a first hair contact member and a second hair contact member disposed on the first arm, and corresponding first and second opposed hair contact members disposed on the second arm, wherein the opposed hair contact members disposed on the first and second arms are arranged to come together when the first and second arms are in the closed configuration; wherein, when the first arm and the second arm are in the closed configuration, the inter-arm chamber is located between the first hair contacting member and the second hair contacting member of the first arm and the second arm; wherein at least one hair contact member comprises a heat applying mechanism for applying heat to a hair segment clamped between the hair contact members when the first arm and the second arm are in the closed configuration during use; and In which, one or both of the arms further include an airflow guiding structure, which is arranged to receive an airflow from a corresponding duct and guide the airflow from a first direction (D1) substantially parallel to the length of the corresponding arm to a second direction (D2) from the corresponding arm toward the opposite arm into the inter-arm chamber.

68. A device for drying or styling hair, comprising: a first arm and a second arm disposed opposite each other, the first arm and the second arm being adapted to move between an open configuration in which the first arm and the second arm receive wet hair segments therebetween, and a closed configuration in which the first arm and the second arm are adjacent to the hair, such that in use, when the first arm and the second arm are in the closed configuration, the first arm and the second arm form an inter-arm chamber through which the hair passes in use, and wherein the airflow conduit is disposed in and along at least one of the first arm and the second arm; a conveying mechanism for conveying a gas flow along the conduit in the at least one of the first arm and the second arm and subsequently conveying the gas flow into the inter-arm chamber; an air heater adapted to heat the air flow; at least one vent through which air from the inter-arm chamber can exit the device; at least one conductive heater configured to heat the hair by conduction in use; control electronics for controlling the device; as well as a sudden cold starter switch or sensing mechanism, the sudden cold starter switch or sensing mechanism being activated by a user of the device, wherein each of the conveying mechanism, the air heater and the at least one conductive heater are switched on during normal use; and Wherein, when the quench starter switch or sensing mechanism is activated by the device user, both the delivery mechanism and the at least one conduction heater are turned on and the air heater is turned off.

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