Haircare appliances and haircare accessories

Abstract

The haircare appliance includes a heater for heating hair, a sensor 22 to detect a thermal property of hair, and a surface 112 located within a field of view FV of the sensor in use. The surface includes a material having an emissivity less than an emissivity of hair. The surface may define or be adjacent a hair receiving zone. The heater may be within a generated airflow with the surface adjacent an outlet. The appliance may have a main body with releasable attachment, where the sensor may be on the main body or attachment. The appliance may have two arms with the surface being an external surface of an arm. Also provided is a kit of a haircare appliance having a heater and sensor, and a haircare accessory having a surface of material with less emissivity than hair. Also provided is an attachment comprising a surface for a haircare appliance.

Description

B ACKGROUND Haircare appliances are generally used to treat or style hair, and some haircare appliances may treat or style hair using airflow and / or heat. SUMMARY According to a first aspect there is provided a haircare appliance comprising: a heater for causing heating of hair; a sensor assembly configured to sense a thermal property of the hair; and a surface arranged to be located within a field of view of the sensor assembly in use, the surface comprising a material having an emissivity less than an emissivity of hair. By sensing a thermal property of the hair, more accurate and / or simpler control of the haircare appliance to provide a desired hair temperature may be provided than, for example, a haircare appliance in which a temperature of the heater, and / or a temperature of airflow heated by the heater, is utilised as a control factor or feedback mechanism. For example, where a temperature of airflow heated by the heater is utilised as a control factor, a distance between an air outlet and hair to be treated may not be accounted for, or more complex control may be required to account for such a distance. By measuring the actual hair temperature, and / or by estimating energy delivered to the hair, more accurate and / or simpler control can be facilitated. Increased accuracy of temperature measurements and / or increased accuracy of estimated energy delivered to hair can also lead to a reduced risk of hair damage. Providing the surface comprising a material having an emissivity less than an emissivity of hair can facilitate detection of hair and hair temperature. For example, in some arrangements where the hair is in contact with, or adjacent to, such a surface in use, the relatively lower emissivity of the surface can facilitate detection of the thermal property of the hair, and also facilitate detection of a position of the hair. In some arrangements where the hair is remote from the haircare appliance, such a surface can be utilised to reflect radiation, such as thermal radiation, from the hair toward the sensor assembly. In either example case, the relatively low emissivity of the surface facilitates sensing of the thermal property of the hair by the sensor assembly, and can lead to more accurate detection of the thermal property of the hair, and / or simpler processing of a signal provided by the sensor assembly, than a haircare appliance absent such a relatively low emissivity surface. In some examples, the surface may be located within a field of view of the sensor assembly. Hair as referred to herein can comprise organic and / or synthetic hair. An emissivity of hair is a predetermined and known quantity, and hair may typically have an emissivity in the region of 0.90 to 0.95. The thermal property of the hair may comprise a temperature of the hair, for example with the sensor assembly sensing the temperature of the hair by capturing thermal radiation emitted by the hair. The sensor assembly may comprise a thermal imaging camera. The sensor assembly may comprise a plurality of thermal imaging cameras, for example distributed about a periphery of the haircare appliance. The material may have an emissivity of less than 0.90, less than 0.80. less than 0.70, less than 0.60, less than 0.50, less than 0.40, less than 0.30, less than 0.20, less than 0.10, or less than 0.05. Such values of emissivity have been found to facilitate detection of hair and / or detection of the thermal property of the hair by providing a good contrast between heated hair and the surface in use, and / or by providing good reflection characteristics for reflecting thermal radiation emitted by the hair toward the sensor assembly. The material may have an emissivity of at least 0.01, at least 0.1, at least 0.2, or at least 0.3. In certain scenarios, for example such as those in which the surface is in contact with or adjacent to hair in use, and a good contrast between the surface and the hair is desirable to facilitate use of the sensor assembly, an emissivity of at least 0.01 may inhibit background environmental radiation from being reflected toward the sensor assembly. The material may have an emissivity of between 0.90 and 0.10, between 00.80 and 0.10, between 070 and 0.10, between 0.60 and 0.10, or between 0.60 and 0.10. Values of emissivity discussed herein may comprise values of emissivity at wavelengths of from 340nm to 14000nm, for example from 5000nm to 15000nm. In examples described herein, the terms radiation or thermal radiation may refer to wavelengths of lOOnm to lOOOOOnm of the electromagnetic spectrum or, more specifically, wavelengths of 5000nm to 15000nm. Use of the wavelength range of 5000nm to 15000nm may be particularly beneficial for drying and styling hair. The surface may have a surface area of at least 5mm2, at least 1cm2, or 3cm2. This may ensure sufficient contrast is achieved between the surface and hair in use, and / or may ensure that sufficient radiation is reflected toward the sensor assembly by the surface in use. The surface may be or comprise a coating formed on a further surface of the haircare appliance, for example with the surface defining a layer on the further surface of the haircare appliance. The surface may solely comprise the material, or may comprise the material embedded alongside one or more further materials. The material may comprise any of a metallic material, a base plastic, or a low-e paint. The material may comprise any of, a nickel coating, an aluminium coating, a chrome coating, a metallic flake paint, and a metallic filler resin. The haircare appliance may comprise a hair receiving zone for receiving the hair, and the surface may comprise at least one of a surface defining the hair receiving zone, and a surface adjacent to the hair receiving zone. This may ensure that, for example, when the surface is in contact with or adjacent to hair in use, a good contrast is achieved between the surface and the hair to facilitate use of the sensor assembly. The heater may be configured to cause heating of hair, such as the heating of hair received within the hair receiving zone. The sensor assembly may be configured to sense a thermal property of hair received within the hair receiving zone. At least a portion of the hair receiving zone may be located within the field of view of the sensor assembly. The surface may be configured to reflect, for example mirror, radiation from hair received within the hair receiving zone to the sensor assembly. The haircare appliance may comprise an airflow generator configured to generate an airflow, the heater may be located within the airflow generated by of the airflow generator and configured to heat the airflow to produce a heated airflow, and the haircare appliance may comprise an air outlet configured to discharge the heated airflow to heat the hair. Use of an airflow to heat hair may inhibit hair damage when compared to an arrangement in which a heated surface is placed in direct contact with hair in use. Use of the surface having an emissivity less than an emissivity of hair in conjunction with such a heated airflow may facilitate non-contact sensing of at least one of a position of the temperature of the hair heated, and the thermal property of the hair heated. The heater may be located downstream of the airflow generator. The air outlet may be configured to discharge the heated airflow into the hair receiving zone, for example through the hair receiving zone. The surface may be adjacent to the air outlet, for example with the air outlet configured to discharge the heated airflow over the surface. Where a surface is located adjacent to the air outlet, and the air outlet is configured to discharge the heated airflow over the surface, the surface may be heated by the heated airflow in use. In the absence of the surface comprising the material having an emissivity less than an emissivity of hair, a surface adjacent the air outlet may be heated to a similar degree as hair in contact with, or adjacent to, that surface in use. This can make it difficult for the sensor assembly to distinguish between the hair and the surface. Accordingly, by providing a surface adjacent to the air outlet, with the surface comprising the material having an emissivity less than an emissivity of hair, detection of the thermal property of the hair by the sensor assembly may be facilitated. The air outlet may be located within the field of view of the sensor assembly, for example within the hair receiving zone. The surface may comprise a contact surface for contacting hair in use, such that one or more styling conditions is imparted to the hair that contacts the surface in use. The haircare appliance may comprise a barrel around which hair is wrapped in use, and the surface may define at least part of an outer surface of the barrel. The surface may be located downstream of the air outlet, for example located downstream of the air outlet about a periphery of the barrel. The surface may be located intermediate the sensor assembly and the air outlet and configured to reflect thermal radiation from a location downstream of the air outlet toward the sensor assembly. Such positioning of the surface may enable the surface to reflect radiation emitted from hair in use toward the sensor assembly, without the surface impacting at least one of a form of the air outlet and airflow characteristics of the heated airflow discharged from the air outlet in use. This may also enable the sensor assembly to sense the thermal property of the hair, rather than any thermal property of the heated airflow discharged from the air outlet, or any thermal property of components of the haircare appliance at or adjacent to the air outlet. The surface may be angled relative to the air outlet, for example obliquely angled relative to a plane of the air outlet. The surface may be configured to reflect radiation from a region located above the air outlet toward the sensor assembly. The haircare appliance may comprise a main body, and an attachment releasably attachable to the main body, and the attachment may comprise the surface. This may, for example, enable selective use of the surface, and may, for example enable the use of a plurality of attachments with the main body, each having a different form of air outlet, and a different configuration of a surface comprising a material having an emissivity less than an emissivity of hair. This may facilitate use of different attachments to achieve different styling conditions for hair to be treated, whilst facilitating sensing of the thermal property of the hair by the sensor assembly in the manner described above. The surface may comprise a surface area that is at least 10% of a total surface area of the attachment, at least 20% of a total surface area of the attachment, at least 30% of a total surface area of the attachment, at least 40% of a total surface area of the attachment, or at least 50% of a total surface area of the attachment. The sensor assembly may be disposed on the main body. This may enable a haircare appliance of reduced complexity compared to, for example, a haircare appliance where the sensor assembly is disposed on the attachment. For example, a main body of the haircare appliance may typically comprise a power source that could be used to power the sensor assembly, whereas an attachment for the haircare appliance may typically not comprise such a power source. Thus providing the sensor assembly on the main body may provide a simpler arrangement than, for example, providing an attachment that either requires power to be transferred from the main body to the attachments, or requires its own power source. The main body may comprise a power source and / or a connection for connecting to an external power source. The attachment may comprise a location feature configured to locate the attachment relative to the main body such that the surface is located within the field of view of the sensor assembly. This may ensure that, where the surface is provided on the attachment, and the sensor assembly is provided on the main body, that the surface is correctly oriented relative to the main body, and in the field of view of the sensor assembly. The attachment may comprise a plurality of discrete surfaces, each discrete surface comprising a material having an emissivity less than an emissivity of hair, and the haircare appliance may be configured such that, with the attachment attached to the main unit, at least one of the plurality of discrete surfaces is located within the field of view of the sensor assembly. This may provide a relatively simple assembly absent the need for a location feature, and ensure that, where the plurality of discrete surfaces is provided on the attachment, and the sensor assembly is provided on the main body, there is always at least one of the plurality of discrete surfaces that is located within the field of view of the sensor assembly. This may provide a haircare appliance of reduced complexity for a user to utilise. The discrete surfaces may be evenly spaced about a periphery of the attachment, for example evenly spaced about a periphery of the barrel of the attachment. The attachment may comprise a plurality of air outlets, for example disposed about a periphery of the barrel of the attachment. Each of the discrete surfaces may be located downstream of a respective one of the air outlets, for example downstream of a respective one of the air outlets about a periphery of the barrel. The attachment may comprise a first end for attachment to the main body, a second end opposite to the first end, and a bore extending from the first end to the second end, and the surface may define the bore. This may enable the attachment to be located in the field of view of the sensor assembly, whilst also enabling the surface to guide radiation emitted from hair, at the second end of the attachment, to the sensor assembly that is disposed on the main body. This may provide flexibility in positioning the sensor assembly on the main body, and may allow for flexibility in design of the attachment. The bore may follow a substantially linear path between the first end and the second end. This may reduce losses in reflected radiation that may otherwise occur if the path were non-linear. The sensor assembly may be disposed on the attachment. Providing both the surface and the sensor assembly on the attachment may enable functionality to be retrofitted to the main body of the haircare appliance. The attachment may comprise a power transfer arrangement configured to receive electrical power from the main body. For example the attachment and the main body may comprise corresponding electrically conductive coils that enable electrical power to be transferred from the main body to the attachment. The haircare appliance may comprise first and second arms spaced apart from one another to define the hair receiving zone, and the surface may be an external surface of the first arm. This may, for example, enable the sensor assembly to distinguish hair from the first arm. The sensor assembly may be located outside of the hair receiving zone, for example facing toward the external surface of the first arm. The haircare appliance may be configured to function as a hair straightener. The external surface of the first arm may be an outward facing surface of the haircare appliance. The surface may be adjacent to at least one of a leading edge of the first arm and a trailing edge of the first arm. When hair is received within the hair receiving zone, a portion of the hair may extend past the first, and second, arms, outside of the hair receiving zone, for example as the haircare appliance is pulled along a tress of hair in use. Providing the surface adjacent to at least one of a leading edge of the first arm and a trailing edge of the first arm may enable the sensor assembly to distinguish between the first arm and the hair at an interface between the first arm and the hair. The surface may extend between the leading edge and the trailing edge of the first arm. The haircare appliance may comprise a further surface comprising the material having an emissivity lower than an emissivity of hair, and the further surface may be an external surface of the second arm. The haircare assembly may comprise a further sensor assembly configured to sense the thermal property of the hair, and the further sensor assembly may face toward the external surface of the second arm. The further surface may be adjacent to at least one of a leading edge of the second arm and a trailing edge of the second arm. The further surface may extend between the leading edge and the trailing edge of the second arm. The haircare appliance may comprise a controller configured to control the haircare appliance based at least in part on a sensor signal output by the sensor assembly. This may enable more accurate control of the haircare appliance to achieve a desired hair temperature than, for example a haircare appliance where control is based on a temperature of airflow at an air outlet. The controller may be configured to control at least one of the heater and the airflow generator based at least in part on the sensor signal output by the sensor assembly. The controller may be configured to decrease a temperature of the heater, and / or decrease a flow rate of the airflow generator, where the sensor signal output by the sensor assembly is indicative of a temperature of the hair exceeding a temperature threshold. The controller may be configured to control the haircare appliance based at least in part on the sensor signal output by the sensor assembly absent any user input. For example, the controller may be configured to control the haircare appliance automatically based at least in part on the sensor signal output by the sensor assembly. The haircare appliance may be configured to provide information regarding the thermal property of the hair to a user, and the controller may be configured to control the haircare appliance in response to a user input. For example, the haircare appliance may comprise a display configured to display the information regarding the thermal property of the hair to the user based at least in part on the sensor signal output by the sensor assembly. The haircare appliance may be configured to transmit the sensor signal, or a further signal based at least in part on the sensor signal, to a remote device, and the sensor signal or the further signal may be configured to cause the remote device to display the information regarding the thermal property of the hair to the user. The remote device may comprise any of a smart phone, a tablet, or any other appropriate computing device. A second aspect provides an attachment for a haircare appliance according to the first aspect, wherein the attachment comprises the surface. For example, an attachment for a haircare appliance may be provided, wherein the haircare appliance comprises a heater for causing heating of hair and a sensor assembly configured to sense a thermal property of the hair, and wherein the attachment comprises a surface arranged to be located within a field of view of the sensor assembly in use, the surface comprising a material having an emissivity less than an emissivity of hair. The surface may comprise at least 25%, at least 50%, or at least 75%, of a total surface area of the attachment. A third aspect provides a kit comprising a haircare appliance and a haircare accessory for use remotely from the haircare appliance, wherein: the haircare appliance comprises a heater for causing heating of hair, and a sensor assembly configured to sense a thermal property of the hair; and the haircare accessory comprises a surface comprising a material having an emissivity less than an emissivity of hair. This may facilitate detection of the thermal property of the hair, and also facilitate detection of a position of the hair, where the haircare appliance is used in conjunction with a haircare accessory, for example a hairbrush or the like. The surface of the haircare accessory may comprise any of the features of the surface of the haircare appliance of the first aspect, where appropriate. Optional features of aspects may be equally applied to other aspects, where appropriate. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of a first example haircare appliance; Figure 2 is a schematic cross-sectional view of a main body of the first example haircare appliance of Figure 1; Figure 3 is a schematic view of an attachment of the first example haircare appliance of Figure 1; Figure 4 is an enlarged schematic view illustrating a field of view of an infrared camera of the main body of Figure 2; Figure 5 is a schematic view of a second example haircare appliance; Figure 6 is a schematic view of a third example haircare appliance; Figure 7a is a first schematic view of a first further attachment for use with the main body of Figure 2; Figure 7b is a second schematic view of the first further attachment of Figure 7a; Figure 8 is a schematic view of a fourth example haircare appliance; Figure 9 is a schematic view of a further attachment for use with a main body of the fourth example haircare appliance of Figure 8; Figure 10 is a first schematic view of a fifth example haircare appliance; Figure 11 is a second schematic view of the fifth example haircare appliance of Figure 10; Figure 12 is a schematic view of a kit comprising a sixth example haircare appliance and a haircare accessory; and Figure 13 is a schematic view of a seventh example haircare appliance. DETAILED DESCRIPTION A first example of a haircare appliance 10 is shown schematically in Figure 1. The haircare appliance 10 comprises a main body 12, and an attachment 100 removably attachable to the main body 12. The main body 12 comprises a housing 14, an airflow generator 16, a heater 18, a control unit 20, and an infrared camera 22, as can be seen schematically in Figures 1 and 2. The housing 14 is tubular in shape, and comprises an air inlet 24 through which an airflow is drawn into the housing 14 by the airflow generator 16, and an air outlet 26 through which the airflow is discharged from the housing 14. The airflow generator 16 is housed within the housing 14, and comprises an impeller 28 driven by an electric motor 30. The heater 18 is also housed within the housing 14, downstream of the airflow generator 16, and comprises heating elements 32 to selectively heat the airflow. The control unit 20 comprises electronic circuitry for a user interface 34 and a control module 36. The user interface 34 is provided on an outer surface of the housing 14, and is used to power on and off the haircare appliance 10, to select a flow rate (for example high, medium and low), and to select an airflow temperature (for example hot, medium or cold). In the example of Figure 1, the user interface comprises a plurality of sliding switches, but other forms of user interface 32, for example buttons, dials or touchscreens, are also envisaged. The control module 36 is responsible for controlling the airflow generator 16, and the heater 18 in response to inputs from the user interface 34. For example, in response to inputs from the user interface 34, the control module 36 may control the power or the speed of the airflow generator 16 in order to adjust the airflow rate of the airflow, and the power of the heater 18 in order to adjust the temperature of the airflow. The control module 36 is also operable in response to a sensor signal received from the infrared camera 22, as will be described in further detail hereinafter. The infrared camera 22 is a sensor assembly in the context of the present application, and is configured to sense a temperature of hair that is wrapped around the attachment 100 in use, as will be described in further detail hereinafter. The infrared camera 22 is positioned on the housing 14 adjacent to the air outlet 26, with a field of view FV of the infrared camera 22 positioned so that the attachment 100 is within the field of view FV when the attachment 100 is attached to the main body 12. The attachment 100 is illustrated in isolation in Figure 3. The attachment 100 comprises a barrel 102 which is generally cylindrical in shape, and has a length extending from an open end 104 to a closed end 106. The barrel 102 is tapered, having a greater diameter at the open end 104 compared to the closed end 106. The open end 104 serves as an inlet to an interior bore of the barrel 102. The open end 104 forms a connection portion having a number of projections 108 disposed around a periphery of the barrel 102, and which are receivable within corresponding recesses (not shown) formed on the main body 12 to ensure correct connection and alignment between the main body 12 and the attachment 100. The projections 108 can be considered to be location formations in the context of the present application. The barrel 102 defines a plurality of air outlets 110. Each of the air outlets 110 is in the form of a slot extending along the length of the barrel 102. Each air outlet 110 is shaped to emit airflow in a same non-radial direction such that, in use, air emitted from the air outlets 110 is emitted in an anti-clockwise direction around the barrel 102. In other examples, the attachment can comprise outlets configured to each emit airflow in one of a clockwise direction and an anti-clockwise direction about the barrel, and a switching mechanism to switch which outlets air flows through in use. Located between adjacent ones of the air outlets are hair contact surfaces 112 about which hair is intended to wrap in use. The barrel 102 can therefore be considered to be a hair receiving zone of the haircare appliance 10. Each hair contact surface 112 is formed by a layer of nickel deposited onto a plastic material that forms the remainder of the barrel 102, and has a surface area of at least 3cm2. Nickel has an emissivity of around 0.05 to 0.60, dependent on factors such as polishing of the surface and surface temperature. It will be appreciated that other materials are also envisaged for the hair contact surface, with the proviso that such materials have a lower emissivity than hair. Hair typically has an emissivity of around 0.9; materials having an emissivity of less than 0.9 are therefore envisaged. Example materials include any of a metallic material, a base plastic, a low-e paint, a nickel coating, an aluminium coating, a chrome coating, a metallic flake paint, and a metallic filler resin. In some examples, a material having an emissivity of greater than 0.1 may be chosen, to inhibit background environmental radiation from being reflected toward the infrared camera 22. In other examples, reflectivity can be modified, for example by modifying a texture of the surface, to achieve a similar effect. Each hair contact surface 112 is curved about a longitudinal axis of the barrel 102, and extends along a full length of the barrel 102, although in other examples hair contact surfaces 112 that do not extend along the full length of the barrel 102 are also envisaged. In use, the attachment 100 is attached to the main body 12 such that one of the hair contact surfaces 112 is located within the field of view FV of the infrared camera 22, as illustrated schematically in Figure 4. A user can operate the user interface 34 to power on the haircare appliance 10. The airflow generator 18 generates an airflow by drawing air into the main body 12 via the air inlet 24, and airflow is emitted from the handle unit 12 via the air outlet 24. The heater 18 heats the airflow before the airflow is emitted from the main body 12. The airflow enters the interior bore of the barrel 102 via the open end 104 of the attachment 100, and is emitted from the barrel 102 via the air outlets 110. Due to the form of the air outlets 110 and the shape of the hair contact surfaces 112, the airflow flows over the hair contact surfaces 112 and sticks to the hair contact surfaces 112 via the Coanda effect. When hair is brought into the vicinity of the barrel 102 whilst the airflow is being generated, the hair is encouraged to wrap around the barrel 102, enabling a curl to be imparted to the hair. As the airflow through the haircare appliance 10 is heated, a temperature of the hair wrapped around the barrel 102 increases during use. The infrared camera 22 monitors a temperature of the hair within the field of view FV of the infrared camera 22, and sends a sensor signal indicative of the temperature of the hair to the control module 36. As the hair contact surfaces 112 are formed of a material, in this case nickel, having an emissivity less than an emissivity of the hair, a relatively good contrast is provided between the hair and the hair contact surfaces 112 for the infrared camera 22, enabling increased accuracy of estimated thermal energy delivered to the hair, as well as enabling improved detection of a position of the hair along the barrel 102. In response to the sensor signal, the control module 36 processes the sensor signal and controls the heater 18 to modify a temperature of the airflow. For example, where the sensor signal is above a temperature threshold, the control module 36 controls the heater 18 to reduce a temperature of the heater 18, and hence reduce a temperature of the airflow emitted from the air outlets 110 of the attachment 100. Such a temperature threshold can be preset, either during manufacture, or by the user, and may inhibit the heated airflow from damaging the hair and / or causing user discomfort in use. Similarly, where the sensor signal is below a temperature threshold, the control module 36 controls the heater 18 to increase a temperature of the heater 18, and hence increase a temperature of the airflow emitted from the air outlets 110 of the attachment 100. Whilst in the example described above the control module 36 automatically controls the heater 18 in response to the sensor signal, other embodiments are also envisaged. For example, the control module 36 can automatically control the airflow generator 16 alternatively or in addition to controlling the heater 18. In some examples, as illustrated schematically in Figure 5, where like reference numerals are used for sake of clarity, a second example haircare appliance 200 comprises a display 202 that displays information regarding the sensed temperature of the hair to the user. The user can then use the user interface 34 to cause the control module 36 to control any of the heater 18 and the airflow generator 16 in the manner previously described. In some examples, as illustrated schematically in Figure 6, where like reference numerals are used for sake of clarity, a third example haircare appliance 300 comprises a transmitter 302, and is configured to transmit the sensor signal from the infrared camera 22 to a smartphone 304 that has a display 306. The display 306 can then be used to display information regarding the sensed temperature of the hair to the user, and the user can then use the user interface 34 to cause the control module 36 to control any of the heater 18 and the airflow generator 16 in the manner previously described. A first further attachment 400 that also makes use of a relatively low emissivity material, and which is suitable for use with the main body 12 of the first through third 10,200,300 examples of haircare appliances described above, is shown schematically in Figures 7a and 7b. The first further attachment 400 comprises an air inlet 402, an air outlet 404, and a low emissivity surface 406. The air outlet 404 is arranged to emit airflow from the first further attachment 400 in a direction substantially orthogonal to a direction in which airflow enters the first further attachment 400 via the air inlet 402. The low emissivity surface 406 is obliquely angled relative to a plane of the air outlet 404, at an angle of 26 degrees. The low emissivity surface 406 is formed of aluminium, and has an emissivity of from 0.04 to 0.6, dependent on factors such as surface polishing and surface temperature. The angle of the low emissivity surface 406 is such that, when the first further attachment 400 is attached to any of the first through third 10,200,300 example haircare appliances, the low emissivity surface reflects radiation, such as thermal radiation, emitted from a position in front of the air outlet 404 to the infrared camera 22. In such a manner, a temperature of hair located in front of the air outlet 404 may be sensed by the infrared camera 22. For the first further attachment 400, materials having an emissivity of less than 0.1 may allow for improved reflection of thermal radiation from hair located in front of the air outlet 404 to the infrared camera 22. A fourth example of a haircare appliance 500 is illustrated schematically in Figure 8, and comprises a main body 502 and an attachment 504. The main body 502 comprises a linear portion 506 and a curved portion 508, and houses an airflow generator 510, a heater 512, and a controller 514. The controller 514 is configured to control the airflow generator 510 and the heater 512 in a manner similar to that described above for the haircare appliance 10 of Figure 1. An air inlet 516 is defined at an end of the linear portion 506, and an air outlet 518 is defined at an end of the curved portion 508. An infrared camera 520 is disposed on the curved portion 508 adjacent the air outlet 518. The attachment 504 has the form of a concentrator nozzle, and has an air inlet 522 and an air outlet 524. An outer surface 526 of the attachment 504 is formed from a nickel coating having an emissivity of from 0.05 to 0.6. The fourth example haircare appliance 500 operates in a similar manner to the first example haircare appliance 10, in that the outer surface 526 of the attachment 504 is effectively not seen by the infrared camera 520 in use. This facilitates easier and / or more accurate detection of a temperature of hair that is dried using the fourth example haircare appliance 500 in use. A further attachment 550 for use with the main body 502 of the fourth example haircare appliance 500 is illustrated schematically in Figure 9. The further attachment 550 has the form of a diffuser, and has a diameter that is such that when the further attachment 550 is attached to the main body 502, the further attachment 550 overlies the infrared camera 520. The further attachment 550 comprises a bore 552 extending from a first end 554 of the further attachment 550, to a second, opposite, end 556 of the further attachment 550. A surface 558 that defines the bore 552 is formed from a chrome coating having an emissivity of from 0.03 to 0.11. The bore 552 is positioned on the further attachment 550 such that when the further attachment 550 is attached to the main body 502, the bore 552 is aligned with the infrared camera 520. In use of the further attachment 550, the bore 552 reflects thermal radiation emitted from hair located at the second end 556 of the further attachment 550 to the first end 554 of the further attachment 550, and to the infrared camera 520. A fifth example haircare appliance 600 is illustrated schematically in Figures 10 and 11. The fifth example haircare appliance 600 comprises a body portion 602, an airflow generator 604, a heater 606, a bellows 608, first 610 and second 612 arms, an infrared camera 614, and a controller 615. The body portion 602 is generally hollow and cylindrical in form, and comprises an air inlet 616 in the form of a plurality of apertures formed in an external surface of the body portion 602. The airflow generator 604 is disposed within the body portion 602, and comprises an electric motor 618 and an impeller 620 driven by the electric motor 618 to generate an airflow through the body portion 602. The heater 606 is located downstream of the airflow generator 604. The bellows 608 is disposed within the body portion 602 downstream of the electric motor 618, and is positioned to receive airflow generated by the airflow generator 604 in use. The bellows 608 forks into first 622 and second 624 ducts, with each of the first 622 and second 624 ducts configured to direct airflow from the body portion 602 into a respective one of the first 610 and second 612 arms. Each of the first 610 and second 612 arms is substantially similar in form, albeit in mirror image to one another, and so only the features of the first arm 610 will be described here for the sake of brevity. The first arm 610 is elongate in form between a first end 626 and a second end 628. The first end 626 of the first arm 24 is pivotably mounted to the body portion 18. The first arm 610 comprises an internal plenum 630, an air outlet 632, and an external surface 634. The internal plenum 630 is in fluid communication with the first duct 622 of the bellows 608, and acts as an airflow path within the first arm 610. The internal plenum 630 begins approximately halfway along the first arm 610 between the first 626 and second 628 ends, and extends to the second end 628 of the first arm 610. The air outlet 632 takes the form of a linear slot that extends along an upper region of the first arm 610. The air outlet 632 is positioned to direct airflow downwardly in a height direction of the first arm 610. The external surface 634 of the first arm 610 is curved between a leading edge 636 of the first arm 610 and a trailing edge 638 of the first arm 610. Here the leading edge 636 of the first arm 610 is an edge of the first arm 610 that is distalmost from the air outlet 632, and which would pass first along a tress of hair in use. The trailing edge 638 of the first arm 610 is an edge of the first arm 610 that is proximal to the air outlet 632, and which would pass last along a tress of hair in use. The external surface 634 is formed from a nickel coating having an emissivity of from 0.05 to 0.6. The second arm 612 is also pivotably mounted to the body portion 602. The first 610 and second 612 arms oppose one another, and defining a hair receiving zone 640. The infrared camera 614 is mounted to the first arm 610, and has a view of the external surface 634 of the first arm 610 that corresponds to the general location of the hair receiving zone 640 along the first arm 610. The controller 615 is electrically coupled to, and configured to receive a signal from, the infrared camera 614. The controller 615 is configured to control the airflow generator 604 and the heater 606 in a manner similar to that described above for the haircare appliance 10 of Figure 1. Here, the relatively low emissivity of the external surface 634 means that a good temperature contrast is provided between hair received within the hair receiving zone 640 and the external surface 636 for the infrared camera 614. A kit 700 comprising a sixth example haircare appliance 702 and a hairbrush 704 is illustrated schematically in Figure 12. The hairbrush 704 can be considered a haircare accessory in the context described herein. The sixth example haircare appliance 702 corresponds to the main body 502 of the fourth example haircare appliance 500, and so will not be described again in detail here for the sake of brevity, save to say that the sixth example haircare appliance 702 comprises the infrared camera 520. The hairbrush 704 comprises a handle portion 706, and a head portion 708 extending from the handle portion 706. The head portion 708 comprises a hair contact surface 710, and a plurality of bristles 712 upstanding from the hair contact surface 710. The hair contact surface 710 is formed from an aluminium coating having an emissivity of from 0.04 to 0.6. Here, the hair contact surface 710 forms an outer surface of a bristle bed of the hairbrush 704. In use, a user can use the sixth example haircare appliance 702 to direct heated airflow toward hair, whilst at the same time using the hairbrush 704 to apply a tension force to the hair via the bristles 712. The hair contact surface 710, having a relatively low emissivity when compared to the emissivity of hair, can provide a good temperature contrast between hair engaged by the hairbrush 704 and the hair contact surface 710 for the infrared camera 520. A seventh example haircare appliance 900 is illustrated schematically in Figure 13, and comprises a main body 902 and an attachment 904. The seventh example haircare appliance 900 is substantially the same as the first example haircare appliance 10, save that the attachment 904 of the seventh example haircare appliance 900 comprises both an infrared camera 906 and a surface 908 formed of nickel, and that the main body 902 and the attachment 904 each comprise corresponding electrically conductive coils for transferring electrical power to the infrared camera 906. The surface 908 has an emissivity from 0.05 to 0.6. The seventh example haircare appliance 900 functions in substantially the same manner as the first example haircare appliance 10 of Figure 1. In each of the example embodiments described above, a surface is provided that has an emissivity less than an emissivity of hair, and this may facilitate detection of hair and hair temperature in use. Whilst various materials been utilised as example materials, it will be appreciated that any material having an emissivity less than an emissivity of hair is envisaged. Although described above as a controller processing a sensor signal to control a heater and / or an airflow generator, in some example the controller may simply act on a processed signal from an infrared camera. Equally, although the embodiments described above utilise an 5 infrared camera, other sensor assemblies that monitor thermal properties of hair are also envisaged.

Claims

1. A haircare appliance comprising:a heater for causing heating of hair;a sensor assembly configured to sense a thermal property of the hair; anda surface arranged to be located within a field of view of the sensor assembly in use, the surface comprising a material having an emissivity less than an emissivity of hair.

2. A haircare appliance as claimed in Claim 1, wherein the material has an emissivity of less than 0.90, less than 0.

80. less than 0.70, less than 0.60, less than 0.50, less than 0.40, less than 0.30, less than 0.20, less than 0.10, or less than 0.05.

3. A haircare appliance as claimed in Claim 1 or Claim 2, wherein the material has an emissivity of at least 0.10.

4. A haircare appliance as claimed in any one of the preceding claims, wherein the surface has a surface area of at least 1cm2.

5. A haircare appliance as claimed in any one of the preceding claims, wherein the haircare appliance comprises a hair receiving zone for receiving the hair, and the surface comprises at least one of a surface defining the hair receiving zone, and a surface adjacent to the hair receiving zone.

6. A haircare appliance as claimed in any one of the preceding claims, wherein the haircare appliance comprises an airflow generator configured to generate an airflow, the heater is located within the airflow generated by the airflow generator and configured to heat the airflow to produce a heated airflow, and the haircare appliance comprises an air outlet configured to discharge the heated airflow to heat the hair.

7. A haircare appliance as claimed in Claim 6, wherein the surface is adjacent to the air outlet.

8. A haircare appliance as claimed in Claim 6 or Claim 7, wherein the air outlet is configured to discharge the heated airflow over the surface.

9. A haircare appliance as claimed in Claim 6 or 7, wherein the surface is located intermediate the sensor assembly and the air outlet, and configured to reflect thermal radiation from a location downstream of the air outlet toward the sensor assembly.

10. A haircare appliance as claimed in any one of the preceding claims, wherein the haircare appliance comprises a main body, and an attachment releasably attachable to the main body, and the attachment comprises the surface.

11. A haircare appliance as claimed in Claim 10, wherein the sensor assembly is disposed on the main body.

12. A haircare appliance as claimed in Claim 11, wherein the attachment comprises a location feature configured to locate the attachment relative to the main body such that the surface is located within the field of view of the sensor assembly.

13. A haircare appliance as claimed in Claim 11, wherein the attachment comprises a plurality of discrete surfaces, each discrete surface comprising a material having an emissivity less than an emissivity of hair, and the haircare appliance is configured such that, with the attachment attached to the main unit, at least one of the plurality of discrete surfaces is located within the field of view of the sensor assembly.

14. A haircare appliance as claimed in Claim 10, wherein the sensor assembly is disposed on the attachment.

15. A haircare appliance as claimed in any one of Claims 10 to 14, wherein the attachment comprises a first end for attachment to the main body, a second end opposite to the first end, and a bore extending from the first end to the second end, and the surface defines the bore.

16. A haircare appliance as claimed in any one of Claims 1 to 6, wherein the haircare appliance comprises first and second arms spaced apart from one another to define the hair receiving zone, and the surface is an external surface of the first arm.

17. A haircare appliance as claimed in Claim 16, wherein the surface is adjacent to at least one of a leading edge of the first arm and a trailing edge of the first arm.

18. A haircare appliance as claimed in any one of the preceding claims, wherein the haircare appliance comprises a controller configured to control the haircare appliance based at least in part on a sensor signal output by the sensor assembly.

19. An attachment for a haircare appliance as claimed in any one of Claims 1 to 18, wherein the attachment comprises the surface.

20. A kit comprising a haircare appliance and a haircare accessory for use remotely from the haircare appliance, wherein:the haircare appliance comprises a heater for causing heating of hair, and a sensor assembly configured to sense a thermal property of the hair; andthe haircare accessory comprises a surface comprising a material having an emissivity less than an emissivity of hair.