Hair drying and / or styling device and method

Abstract

A hair styler 1 is disclosed which includes ultra-wide band (UWB) sensors 318-2 to detect the proximity of the hair styler to a user’s head during use to control settings and / or functions of the hair

Description

The present invention relates to an apparatus and method for drying and / or styling the hair of a person (or conceivably an animal), for example after washing the hair or as part of a styling process, and a means of controlling that apparatus during the drying and / or styling process. Typically, handheld (portable) hair stylers (e.g., hair straightening and / or curling devices) are provided with one or more user interfaces that allow the user to set user defined parameters for the device. For example, the one or more user interfaces may allow a user to set a desired operating temperature of the hair styler, and / or request a cool / heat shot. The one or more user interfaces may also allow a user, by way of example only, to select one or more styling programs to be used to style their hair. For example, the hair styler may have pre-programmed styling programs stored within its memory that set specific parameters necessary to achieve a particular hair style. Additionally, the one or more user interfaces may also allow a user to switch between different operating modes of the hair styler. For example, the user may switch between a training mode where the heaters of the hair styler are switched off allowing a user to practise particular styling techniques and moves without actually styling their hair, and a styling mode, where the heaters of the hair styler are operable. In the scenario where a user selects one or more styling programs to be used to style their hair, the hair styler may use pre-programmed styling programs stored within its memory that set specific parameters necessary to achieve the particular hair style selected. However, although the user does not have to input / change specific parameters of the hair styler to achieve the desired hair style they have selected, the user still needs to be well versed in the techniques and movements that need to be performed with the hair styler to achieve the selected style. This in turn means that the average user generally does not attempt complex styles because of the complexity of the techniques and movements required. Furthermore, even with simpler styles, a user who is not accustomed to the hair styler may still make mistakes when attempting to achieve the desired style. There is thus a need to incorporate monitoring and feedback functionality into such hair stylers that can monitor the techniques and movements being used by a user and assist them when using the hair styler to achieve their desired hair style. Similar issues arise with hair dryers and dual functionality stylers such as the applicant’s “Duet Style” hair drying and styling device. Summary of Invention In an aspect of the invention there is provided a hair drying and / or styling device comprising a first ultra-wide band, UWB, sensor located on hair styling device for transmitting UWB radio pulses and for receiving UWB radio signals reflected by objects in the vicinity of the first UWB sensor, and a processor in communication with the first UWB sensor. The processor is configured to process signals obtained from the first UWB sensor to detect when the hair drying and / or styling device is in proximity to a user’s head, and perform a control action in response to detecting that the hair drying and / or styling device is in proximity to a user’s head. In another aspect, the control action comprises providing feedback to the user. For example, feedback provided to the user comprises at least one of: audio feedback, visual feedback, and / or haptic feedback. In another aspect, the control action comprises controlling a power delivered to at least one heater of the hair drying and / or styling device. In another aspect, the hair drying and / or styling device further comprises a second UWB sensor, the first and the second UWB sensors being located on either side of the hair drying and / or styling device, and the processor is in communication with the first and second UWB sensors. The processor is also configured to process signals obtained from the first and second UWB sensors to detect a side of the hair drying and / or styling device on which a user’s head is located. In another aspect, the processor is configured to compare the signals obtained by the first and the second UWB sensors to determine which of the signals has the largest amplitude peak, and determine, based on which of the signals has the largest amplitude peak, which side of the hair drying and / or styling device on which a user’s head is located. For example, the user’s head may be determined to be on the side of the hair styler device corresponding to the side on which the UWB sensor that received the signal with the largest amplitude peak is located. In another aspect, comparing the signals obtained by the first and the second UWB sensors comprises generating, for each of the signals obtained by the first and the second UWB sensors, a distance-amplitude graph, and analysing each distanceamplitude graph to identify which of the distance-amplitude graph contains the largest amplitude peak. In another aspect, the hair styling device further comprises a pressure sensor located proximal to the first and / or the second UWB sensor. Furthermore, the processor is further configured to determine, based on data obtained from the pressure sensor, whether a user’s hand is positioned proximal to the first and / or second UWB sensor. In response to determining that the user’s hand is proximal to the first and / or second UWB sensor, applying a correction to the signals obtained from the first and / or UWB sensor to account for UWB radio signals reflected off the user’s hand. In another aspect, the processor is further configured to determine an orientation of the hair drying and / or styling device with respect to magnetic north. In another aspect, the processor is in communication with orientation sensing circuitry configured to sense an orientation of hair drying and / or styling device , and wherein the processor is configured to process data received from the orientation sensing circuitry to determine an orientation of the hair drying and / or styling device with respect to magnetic north. For example, the orientation sensing circuitry comprises at least one of: an accelerometer, a gyrometer, and / or a magnetometer. In another aspect, the processor is configured to perform a control action in response to determining the orientation of the hair drying and / or styling device and detecting that the hair drying and / or styling device is in proximity to a user’s head. In another aspect, the computing device further comprises a user interface for selection of a desired hair style by a user, and the processor is further configured to determine movement of the hair styling device, compare the determined movement with a set of movements necessary to achieve the desired hair style to determine whether the movement is correct to achieve the desired hair style, and perform a control action based on the determination of whether the movement is correct to achieve the desired hair style. In another aspect, the processor is configured to re-determine the orientation of the hair styling device, compare the orientation and the re-determined orientation of the hair styling device, and determine, based on the comparison, a movement of the hair styler device. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, and with reference to the drawings in which: Figure 1a illustrates a perspective overview of a hair styling device; Figure 1b illustrates the device of Figure 1a when in use to style hair; Figure 2 illustrates a hair styler 1 that includes a computing device; Figure 3a illustrates the computing device 310 components and modules; Figure 3b illustrates the circuitry of the UWB sensors; Figure 4a depicts a graph showing a comparison of an actual orientation of the hair styler with a predicted orientation; Figure 4b illustrates the roll, pitch, and yaw angles of rotation of the hair styler; Figure 5a illustrates one example of the hair styler in use; Figure 5b depicts signal amplitude-distance graphs of reflected UWB signals received at the UWB sensors located on the hair styler; Figures 5c and 5d illustrate an example movement of the hair styler and the feedback that can be provided; Figure 6 illustrates a process flow chart of the steps involved in providing feedback to a user; Figure 7a illustrates another example of the hair styler 1 in use; Figures 7b and 7c depict another set of signal amplitude-distance graphs of reflected UWB signals received at the UWB sensors located on the hair styler; and Figure 8 illustrates another process flow chart of the steps involved in providing feedback to a user. Overview Figure 1a illustrates a handheld (portable) hair styler 1. The hair styler 1 includes a first movable arm 4a and a second movable arm 4b, which are coupled at proximal ends thereof to a shoulder 2. The first arm 4a bears a first heater 6a at its distal end, and the second arm 4b bears a second heater 6b at its distal end. The first and second heaters 6a, 6b oppose one another and are brought together as the first and second arms 4a, 4b are moved from an open configuration to a closed configuration. As shown in Figure 1b, during use, a tress of hair 40 is sandwiched between the two arms 4 so that the user’s hair is in contact with, and therefore heated by, outer heating surfaces of the heaters 6a, 6b. Therefore, as the user pulls the hair styler 1 along the tress of hair 40, the tress of hair 40 is heated by conductive heating to a suitable temperature to facilitate styling. One or more user interfaces 11 are provided to allow the user to set user defined parameters and for the device to output information to the user. For example, a desired operating temperature may be set via the user interface 11. The user interface 11 may have a dial, button, or touch display for allowing the user to input information to the hair styler 1 and the user interface 11 may have an indicator light, display, sound generator or haptic feedback generator for outputting information to the user. In this embodiment, the user interface 11 also comprises a control button or switch 14 to enable the user to turn the hair styler 1 on or off; and an indicator light 15 to show whether the power is on. A printed circuit board assembly (not shown) may be provided at any suitable location within the housing of the hair styler 1 and carries the control circuitry for controlling the operation of the hair styler 1 and for controlling the interaction with the user via the user interface 11. In this example, electrical power is provided to the hair styler 1 by means of a power supply located at an end of the device, via a power supply cord 3. The power supply may be an AC mains power supply. However, in an alternative embodiment the power supply may comprise one or more DC batteries or cells (which may be rechargeable, e.g., from the mains ora DC supply via a charging lead), thereby enabling the hair styler 1 to be a cordless product. Alternatively, the printed circuit board assembly (not shown) may be provided at any other suitable location. For example, the printed circuit board may be provided as part of the power supply (e.g., on a modified plug or the like), or as a separate brick / box on the power cable. In use, the hair styler 1 is turned on, energising the heaters 6 to cause them to heat up. The user then opens the first and second arms 4a, 4b and, normally starting from the roots of the hair (i.e., near the scalp), a length or tress of hair 40 (which may be clumped) is introduced between the arms 4a, 4b, transversely across the heaters 6a, 6b. The user then closes the arms 4a, 4b so that the length of hair 40 is held between the first and second arms 4a, 4b and then the user pulls the hair through the closed arms (as illustrated in Figure 1b). The outer (hair contacting) surface of the heaters 6 is flat in this embodiment and so the hair styler 1 can be used to straighten the user’s hair. The hair styling hair styler 1 shown in Figure 1 can also be used to curl the hair by turning the hair styler 1 through approximately 180 degrees or more after clamping the hair between the arms 4a, 4b and before moving the hair styler 1 along the tress of hair 40. Additionally, in use, the one or more user interfaces that allow the user to set user defined parameters for the device, may also allow a user, by way of example only, to select one or more styling programs to be used to style their hair. For example, the hair styler may have pre-programmed styling programs stored within its memory that set specific parameters necessary to achieve a particular hair style. In the scenario where a user selects one or more styling programs to be used to style their hair, the hair styler may use pre-programmed styling programs stored within its memory that set specific parameters necessary to achieve the particular hair style selected. However, although the user does not have to input / change specific parameters of the hair styler to achieve the desired hair style they have selected, the user still needs to be well versed in the techniques and movements that need to be performed with the hair styler to achieve the selected style. The techniques and movements that need to be performed with the hair styler to achieve specific selected styles however can, in some cases, be complex and difficult to remember, especially where numerous steps are involved. In one aspect of the invention disclosed herein, a hair styling device is provided that has one or more ultra-wide band (UWB) sensors incorporated within it to transmit UWB radio pulses and to receive UWB radio signals reflected by objects adjacent to the UWB sensors. Data from those one or more UWB sensors may in turn be processed by a processor of the hair styling device to determine things such as: i) relative positions of a user’s head with respect to a side of the hair styling device, ii) rotational movement of the hair styling device, iii) axial movement of the hair styling device, and the like. Additionally, the hair styling device is provided with means of providing feedback to users such as haptic, audio, and / or visual feedback. Beneficially, by using one or more UWB sensors to determine i) relative positions of a user’s head with respect to a side of the hair styling device, ii) rotational movement of the hair styling device, iii) axial movement of the hair styling device, and the like, the hair styling device is able to compare its live movement with pre-stored movements in its memory that are necessary to achieve specific styles to determine whether the user is using the hair styler correctly. In response to determining that the hair styler is being used correctly (or not as the case may be), the hair styler can provide appropriate feedback to the user, thereby assisting the user in achieving a specific selected style. In one aspect of the invention disclosed herein, the hair styling device is provided with one or more UWB sensors on either side of the hair styler to allow the detection of objects on either side of the hair styler (e.g., the detection of a user’s head). In addition, the hair styling device may be provided with appropriate apparatus and electrical circuitry to determine an orientation of the hair styler (e.g., accelerometers, gyroscopes, magnetometers, and the like). Beneficially, by providing one or more UWB sensors on either side of the hair styler in conjunction with the appropriate apparatus and electrical circuitry to determine an orientation of the hair styler, the hair styler can determine its position relative to a user’s head. For example, it can determine whether a user’s head is to the right or the left of the hair styler. In conjunction with the ability to determine rotational movement of the hair styling device, axial movement of the hair styling device, and the like, the hair styler beneficially can determine movements of the hair styling device relative to a user’s head (e.g., the direction of a curling movement relative to a user’s head). Such movements can be compared with pre-stored movements in its memory that are necessary to achieve specific styles to determine whether the user is using the hair styler correctly. In response to determining that the hair styler is being used correctly (or not as the case may be), the hair styler can provide appropriate feedback to the user, thereby assisting the user in achieving a specific selected style. In another aspect of the invention disclosed herein, the hair styling device is provided with pressure sensors to enable the detection of a user’s hand on the hair styling device, and in particular to enable the detection of a user’s hand on the hair styling device in the proximity of the UWB sensors. Beneficially, by providing pressure sensors to determine whether a user’s hand is in the proximity of the UWB sensors, corrections to the data received from the UWB sensors can be made to ensure that erroneous detections of a user’s head are not made. Each configuration of the hair styler system briefly summarised above will now be discussed in more detail with reference to Figures 2 to 8. Hair Styler Feedback Control System Figure 2 illustrates a hair styler 1 that includes a computing device 210 within the hair styler 1. For example, the computing device may take the form of one or more printed circuit boards (PCBs) with electrical components thereon that provide computer processing capabilities to process data collected by one or more sensors of the hair styler 1. Alternatively, (not shown), the hair styler 1 may be in communication with an external computing device 210 that provides computer processing capabilities to process data collected by one or more sensors of the hair styler 1 and communicated to the external computing device 21 over a communication link (e.g., via Wi-Fi, Bluetooth, local area network (LAN) connectivity, or the like). The computing device 210 comprises a processor 314 (such as a microprocessor or CPU), a memory 312, and several modules that provide specific sensing and control circuitry. By way of example only, the computing device 210 may comprise an orientation module 316 configured to make orientation measurements and determine an orientation of the hair styler 1 with respect to a particular reference point (e.g., a user’s head / body). The computing device 210 may comprise a proximity module 318 configured to make proximity measurements and determine a proximity of the hair styler 1 to a particular reference point (e.g., a user’s head / body). Furthermore, the computing device 210 may comprise a feedback module 320 configured to provide appropriate feedback to a user. For example, the feedback module 320 may be configured to allow the provision of at least one of audio, or haptic, or visual feedback. Nevertheless, it will be appreciated that the feedback module 320 may be configured to allow the provision of any appropriate type or types of feedback to a user to make indication to the user. In one example, the feedback may be audio feedback provided by one or more speakers provided in the hair styler 1. In this scenario, the audio feedback may be triggered by the feedback module 320 of the computing device 210 within the hair styler 1. Alternatively, where the computing device 210 is an external computing device 210 the audio feedback may be triggered by the external computing device 210 sending an appropriate message or command to the hair styler 1 over a communication link between the external computing device 210 and the hair styler 1. Additionally, or alternatively, where the computing device 210 is an external computing device 210 the audio feedback may be provided by one or more speakers of the external computing device 210. In another example, the feedback may be haptic feedback provided by one or more haptic units provided in the hair styler 1. In this scenario, the haptic feedback, which may for example include vibrations of the hair styler 1, may be triggered by the feedback module 320 of the computing device 210 within the hair styler 1. Alternatively, where the computing device 210 is an external computing device 210 the haptic feedback may be triggered by the external computing device 210 sending an appropriate message or command to the hair styler 1 over a communication link between the external computing device 210 and the hair styler 1. In another example, the feedback may be visual feedback provided by one or more user interfaces (Uis) and / or displays provided in the hair styler 1. In this scenario, the visual feedback may be triggered by the feedback module 320 of the computing device 210 within the hair styler 1. Alternatively, where the computing device 210 is an external computing device 210 the visual feedback may be triggered by the external computing device 210 sending an appropriate message or command to the hair styler 1 over a communication link between the external computing device 210 and the hair styler 1. Additionally, or alternatively, where the computing device 210 is an external computing device 210 the visual feedback may be provided by one or more Uis and / or displays of the external computing device 210. The modules and circuitry of the computing device 210 used in the monitoring and control of the hair styler 1 briefly described above will now be described in more detail with reference to Figure 3. Figure 3a illustrates the computing device 310 components and modules of the hair styler 1. As shown in Figure 3a, the computing device 310 comprises several circuitry components and modules for monitoring the use of the hair styler 1 and to provide appropriate feedback to a user. The computing device 310 may comprise its own power source 324, or alternatively may be connected to another power source such as a power source of the hair styler 1 itself. The computing device 310 also has a processor 312 powered by the power supply 324. The processor 312 comprises a microprocessor 312-1 and a memory 314, or alternatively, the memory 314 may be separate to the processor 312 but connected to the processor 312 via appropriate wiring / coupling. There is also provided one or more user interfaces 326 coupled to the microprocessor 312-1, for example to provide one or more user controls and / or output indications such as a visual indication. There is also provided drive circuitry 328 coupled to the microprocessor 312-1, for example to control the power provided to the heaters 328-1 of the hair styling device 1. By way of example only, power is provided to the heaters 328-1 for providing heat via the hair styling device 1 to a user’s hair. The power supplied to the heaters 328-1 is controlled by the microprocessor 312-1 via drive circuitry 328. For example, the power supplied to the heaters 328-1 may be controlled by drive circuitry 328 (which may include one or more power semiconductor switching devices (triacs)) which may control the application of a voltage derived from the power source 324 in accordance with instructions from the microprocessor 312-1. The microprocessor 312-1 is coupled to a memory 314 (which is typically a non-volatile memory) that may, by way of example only, store processor control code for implementing one or more control methods that control the heating of the heaters 328-1 in accordance with a desired operating temperature of the heaters 328-1 and a proximity of the hair styler 1 to a user. There is also provided an orientation module 316 coupled to the microprocessor 312-1, for example to provide capabilities to determine an orientation of the hair styler 1 relative to a particular reference point (e.g., a user’s head / body). The orientation module 316 comprises orientation sensing circuitry 316-1 to allow the microprocessor 312-1 to communicate with, and collect data from, one or more orientation sensing based devices that are configured to collected data relating to the orientation of the hair styler 1 relative to a particular reference point (e.g., a user’s head / body). By way of example only, the one or more orientation sensing based devices may include at least one of: a magnetometer 316-2, ora gyrometer 316-3, or an accelerometer 316-4. In one example the one or more orientation sensing based devices may include at least the magnetometer 316-2. The magnetometer 316-2 may be used to measure a magnetic force on the magnetometer. For example, the magnetometer may be used to measure the Earth’s gravitational field in order to determine a compass bearing of the hair styler i.e., the hair styler’s 1 orientation with respect to the Earth’s gravitational field. In another example the one or more orientation sensing based devices may include at least the gyrometer 316-3. The gyrometer 316-3 (i.e., a gyroscope 316-3) may be located within the hair styler 1 to detect movement of the hair styler 1. The gyroscope 316-3 in the hair styler 1 may be used to determine whether the hair styler 1 is in use (i.e., whether it is being moved around, or whether it is stationary). The gyroscope 316-3 may also be used to measure angular motion (e.g., rotation) of the hair styler 1 in space. In another example the one or more orientation sensing based devices may include at least the accelerometer 316-4. The accelerometer 316-4 may be located within the hair styler 1 to measure the acceleration (the rate of change of velocity) of the hair styler 1 in its own instantaneous rest frame. While the examples above describe the implementation of gyroscopes, accelerometers, and magnetometers individually, it will nevertheless be appreciated that any number of, and combination of, such devices may be implemented in the hair styler 1 to provide orientation sensing capabilities. There is also provided in the computing device 310 a proximity module 318 coupled to the microprocessor 312-1, for example to provide capabilities to determine a proximity of the hair styler 1 to a particular reference point (e.g., a user’s head / body). The proximity module 318 comprises proximity sensing circuitry 318-1 to allow the microprocessor 312-1 to communicate with, and collect data from, one or more proximity sensing based devices that are configured to collected data relating to the proximity of the hair styler 1 relative to a particular reference point (e.g., a user’s head / body). By way of example only, the one or more proximity sensing based devices may include at least an ultra-wide band (UWB) sensor 318-2. A UWB sensor 318-2 may include a transceiver that transmits UWB pulses and receives reflected UWB pulses. For example, the transceiver may be capable of transmitting approximately 1 pulse every 10 - 100 ms across a wide spectrum frequency range (e.g., at least 500 MHz wide) toward the user. The transceiver may also be capable of receiving reflected pulses every 10 - 100 ms, reflected off of the user. It will be appreciated that while the UWB sensor 318-2 is described herein as having a transceiver that facilitates both transmission and reception of radio pulses, the UWB sensor may alternatively be provided with a separate transmitter and receiver capable of transmitting and receiving pulses respectively. The circuitry of the UWB sensor 318-2 is described in more detail below with reference to Figure 3b. There is also provided in the computing device 310 a feedback module 322 coupled to the microprocessor 312-1, for example to provide feedback to a user of the hair styler 1. The feedback module 322 comprises feedback circuitry 322-1 and at least one means of providing feedback to a user of the hair styler 1. For example, as shown in Figure 3a, there is provided a haptic unit 322-2 that is configured to provide haptic feedback to a user (e.g., vibrations, sequences of vibrations, patterns of vibrations, and the like, via the hair styler 1). Nevertheless, it will be appreciated that a haptic unit 322-2 is only one possible example of a feedback unit that may be provided. In another example, (not shown), there may be provided, additionally to the haptic unit, or alternatively to the haptic unit, an audio feedback unit that allows audio feedback (e.g., sounds) to be provided to a user of the hair styler 1. For example, the audio feedback unit may include one or more speakers capable of providing audio as a feedback indication to a user of the hair styler 1. In another example (not shown), there may be provided, additionally or alternatively to the haptic unit and / or the audio unit, a visual feedback unit that allows visual feedback (e.g., indications on displays, LEDs, and the like) to be provided to a user of the hair styler 1. For example, the visual feedback unit may include appropriate circuitry to allow indications to be signalled to a user via one or more Uis of the hair styler 1 such as a display screen, LED lights or the like. While the examples above describe the implementation of haptic, audio, and visual feedback individually, it will nevertheless be appreciated that any number of, and combination of, such feedback types may be implemented in the hair styler 1 to provide appropriate feedback to a user while they are operating the hair styler 1. It will be appreciated that while the above description refers to a computing device 310 within the hair styler 1, nevertheless the computing device 310 may alternatively be external to the hair styler 1. For example, the computing device 310 may be a smart device linked to the hair styler 1 over Wi-Fi / Bluetooth (e.g., a smartphone). Figure 3b illustrates the circuitry of the one or more UWB sensors 318-2 incorporated in the hair styler 1. This circuitry is conventional and is included for completeness. As those skilled in the art will appreciate other kinds of UWB circuitry could be used to transmit and receive the UWB signals. As shown in Figure 3b, the UWB sensor 318-2 includes an oscillator 318-3 and a pulse generator 318-4 to generate ultra-wide band pulses. The ultra-wide band pulses are passed through a modulator (or pulse shaper) 318-5 to prepare the pulses for transmission by transmission (Tx) antenna 318-7. As shown in Figure 3b, prior to transmission by Tx antenna 318-7, the modulated pulses may also be passed through a power amplifier 318-6 to increase the power (i.e., the amplitude) of the transmitted UWB pulses. The UWB sensor 318-2 also includes a receiver (Rx) antenna 318-8 for receiving reflected UWB signals. Once received by the Rx antenna 318-8, the reflected UWB signals may be passed through a low-band pass filter 318-9 that removes unwanted high frequency and low frequency signals. The reflected UWB signals are also passed through a low-noise amplifier 318-10 to amplify very low-power signals without significantly degrading their signal-to-noise ratio (SNR). The reflected UWB signals (and / or information pertaining to those reflected UWB signals) are then processed by the processor 312 of the computing device 310. For example, reflected UWB signals (and / or information pertaining to those reflected UWB signals) may be processed by the processor 312 to determine a proximity of a user of the hair styler 1 to the hair styler 1 as will be described in more detail later. Optionally, prior to being processed by the processor 312 of the computing device 310, the reflected UWB signals may also be passed through a correlator receiver 318-11 to correlate the reflected UWB signals with the UWB pulses transmitted by the Tx antenna 318-7. For example, the reflected UWB signals may be passed through a mixer 318-12 to mix the UWB pulses and the reflected UWB signals with the output of the mixer 318-12 being integrated by the integrator 318-13 prior to being processed by the processor 312 of the computing device 310. Orientation Calculation During use, as the user moves and / or rotates the hair styler 1, the orientation module 316 determines an orientation of the hair styler 1 with respect to a reference point (e.g., with respect to a user’s head / body, or alternatively, with respect to the direction of the Earth’s magnetic field). To determine the orientation, the microprocessor 312-1 in communication with the orientation module 316 may request and collect data from at least one of a magnetometer 316-2, or a gyrometer 316-3, or an accelerometer 316-4. For example, the microprocessor 312-1 in communication with the orientation module 316 may use the magnetometer 316-2 to measure a magnetic force on the magnetometer. For example, the magnetometer 316-2 may be used to measure the Earth’s gravitational field in order to determine a compass bearing of the hair styler i.e., the hair Styler’s 1 rotation with respect to the magnetic north. Additionally, or alternatively, the microprocessor 312-1 in communication with the orientation module 316 may use the gyrometer 316-3 to measure a rotational velocity of the hair styler 1. For example, the gyrometer 316-3 may be used to measure a rate of rotation and / or angular momentum of the hair styler 1 to as the user moves the hair styler 1 to determine a tilt and / or lateral orientation of the hair styler 1. Additionally, or alternatively, the microprocessor 312-1 in communication with the orientation module 316 may use the accelerometer 316-4 to measure a linear motion of the hair styler 1. For example, the accelerometer 316-4 may be used to measure a rate of change of velocity of the hair styler 1 in a linear direction as the user moves the hair styler 1. Based on some, or all of the data measured by the magnetometer 316-2, or a gyrometer 316-3, or an accelerometer 316-4, the microprocessor 312-1 determines a rotational matrix R that describes, in linear algebraic terms, a rotation of the hair styler 1 in Euclidean space. The rotational matrix R is described algebraically as follows in Equation 1: R = costa) x costfi) cos(a) x costp) x sin(y) — sin(a) x cos(y) cos(a) x sinfjS) x cos(y) + sin (a) x sin(y) sin^a) x costp) sin(a) x cos(p) x sin(y) + cos(a) x cos(y) sinta) x sintp) x cos(y) - cos(a) x sin(y) —sintP) cos(p)xsmtY') cos(p)xcos(y) Eq. 1 Wherein: a = roll angle P = pitch angle y = yaw angle Figure 4a illustrates the roll, pitch, and yaw angles of rotation of the hair styler 1. As shown in Figure 4a, the roll angle a corresponds to rotation of the hair styler 1 about the Z-axis as labelled in Figure 4a, the pitch angle |3 corresponds to rotation of the hair styler 1 about the Y-axis as labelled in Figure 4a, and the yaw angle y corresponds to rotation of the hair styler 1 about the X-axis as labelled in Figure 4b, wherein the X-, Y-, and Z-axis used have their usual meaning in Euclidean geomertry (i.e., the Cartesian coordinate system). Once the rotational matrix R is determined, the microprocessor 312-1 in communication with the orientation module 316, uses the accelerometer 316-4 (and / or the magnetometer 316-2, and / or a gyrometer 316-3) to measure a linear motion of the hair styler 1, and determine an acceleration vector A of the hair styler 1. The acceleration vector A is described algebraically as follows in Equation 2: A = [ax, ay, az] Eq. 2 Wherein: ax — acceleration in the X direction ay = acceleration in the Y direction az = acceleration in the Z direction Once both the rotational matrix R and the acceleration vector A are determined, the microprocessor 312-1 calculates the angular acceleration An of the hair styler 1 by calculating the dot product of the rotational matrix R and the acceleration vector A as follows: A„ = R A Eq. 3 Once the rotational matrix R and the angular acceleration An is determined, the microprocessor 312-1 may determine the (new) orientation of the hair styler 1 which is a function of An as follows: F(An) = An + c = orientation Eq. 4 Wherein: c = A - [0, 0,1] For example, the microprocessor 312-1 may compare An with an initial orientation matrix of the hair styler 1 stored in its memory to determine changes in its orientation. Beneficially, by determining the orientation of the hair styler 1 using An, only An and an initial orientation matrix of the hair styler 1 has to be stored in the memory 314 of the hair styler 1 thereby reducing the amount of memory storage needed, increasing memory usage efficiency. In addition, the manner in which the microprocessor 312-1 determines the orientation of the hair styler 1 only requires the comparison of two matrices that are simple to calculate, thereby reducing the amount of time needed for the microprocessor 312-1 to make the calculations. Figure 4b depicts a graph showing a comparison of an actual orientation of the hair styler 1 with a predicted orientation made by the orientation module 316. As shown in Figure 4b, the new, efficient proposed method of determining the orientation of the hair styler 1 produces accurate orientation determinations. Beneficially, by determining the orientation of the hair styler 1 in the above manner Gimbal-locking is prevented. Having accurately determined the orientation of the hair styler 1, its position relative to a user’s head may then subsequently be determined and, where appropriate, feedback may be provided to a user during their use of the hair styler 1 based on its orientation and position relative to a user’s head. Feedback Figure 5a illustrates one example of the hair styler 1 in use. During use the microprocessor 312-1 performs the orientation determination calculations described above to determine an orientation of the hair styler 1 relative to magnetic north. At the same time (or shortly thereafter) the microprocessor 312-1 may also determine whether the hair styler 1 is close to a user’s head, and more particularly which side of the hair styler 1 is close to the user’s head. For example, as shown in Figure 5a, the hair styler 1 may also be provided, by way of example only, with at least two proximity sensors 320a, 320b; one on either side of the hair styler 1. The two proximity sensors 320a, 320b may, for example, be Ultra-Wide Band (UWB) sensors, or any other appropriate type of sensor capable of determining a proximity of a user to the hair styler 1 e.g., optical sensors, radar sensors, magnetic sensors, and the like. For the purpose of illustration, all further discussion of the at least two proximity sensors 320a, 320b will relate to at least two UWB sensors. During use, the at least two UWB sensors 320a, 320b emit UWB pulses of electromagnetic radiation. For example, the UWB sensors 320a, 320b may emit pulses in the band range of 500 MHz or greater and may pulse every 10-100 ms. Those pulses in turn travel through air and space until they reach an object or surface from which they are reflected. Upon hitting an object or surface (e.g., the side of a user’s head, a wall, or some other object in the vicinity of the UWB sensors) the pulses are reflected off the object or surface in the form of a reflected UWB radio signal. Some or all of those reflected UWB signals (depending on the angle of reflection) will in turn be picked up by the Rx antenna 318-8 of the UWB sensor, which is in turn processed by the Rx antenna circuitry of the UWB sensor as described above with reference to Figure 3b. The time of arrival (ToA) of each of those reflected radio signals is dependent on how far away the object is off of which the radio pulse was reflected. Accordingly, the reflected radio pulse signals may be used to determine relative distances between the hair styler 1 and objects in the vicinity of the hair styler 1. Furthermore, it will be appreciated that the power (e.g., amplitude) of such reflected radio signals will depend on various factors including the surface area of the object from which the radio pulses are reflected. Accordingly, the reflected radio signals may also be used to determine sizes of objects in the vicinity of the hair styler 1. Each reflected UWB radio signal received at the receiver comprises a linear combination of reflected radio pulses from M different objects (paths or directions) and an additive noise term. Thus, the received UWB signal can be represented algebraically as: Mpath anis(n, k-Tj + N wherein: s(n.k) is the estimate of the transmitted pulse shape received at the receiver that is usually distorted due to several different factors, such as the reflection, refraction and scattering coefficients of the objects, N is additive noise, a™ is a scaling factor of the signal reflected from the ith object, and Ti is the delay of the reflected pulse that depend on the distance between the ith object and the USB sensor. Once generated, each reflected UWB radio signal may also have corrections applied to it where appropriate to remove ‘clutter’ from the signals. Clutter is defined as aspects of the reflected pulse signals (also referred to simply as ‘reflected signals’) that are caused by background objects, which is to say objects that are far away from the UWB sensors 320a, 320b e.g., walls in the background behind the user. By applying such corrections, the remaining features of each reflected UWB radio signal is made clearer, enabling the processor to identify the presence of objects more clearly in the foreground of the hair styler 1. By way of example only, clutter in the signals may be removed by a loopback filter. Once processed by the Rx antenna circuitry of the UWB sensor, the processed reflected UWB signal(s) (or information pertaining to such a processed reflected UWB signal) are passed to the processor 312 of the computing device 310 for further processing; for example, to determine a proximity of the hair styler 1 (or a side thereof) to the head of a user. By way of example, as shown in Figure 5a, during use the at least two UWB sensors 320a, 320b of the hair styler 1 each emit UWB pulses which propagate through air and space. The pulses 330a emitted from the UWB sensor 320a propagate through air and empty space as shown in Figure 5a. During their propagation they may or may not interact with an object in the distance such as a wall. Those pulses 330a in turn will be reflected off the wall and a reflected UWB signal will, at some future time Xi, be received by the Rx antenna 318-8 of the UWB sensor 320a. On the other hand, during the propagation of the pulses 330b emitted from the UWB sensor 320b, the pulses 330b interact with the head 340 of the user that is in close proximity to the UWB sensor 320b. Those pulses 330b in turn will be reflected off the user’s head 340 and a reflected UWB signal will, at some future time X2 be received by the Rx antenna 318-8 of the UWB sensor 320b. Based on the power (amplitude) of the reflected UWB signal (which as indicated above may be dependent on the size of the surface area off of which the pulses 330a, 330b reflect), and the distance that the object is from the sensor, the processor 314 of the computing device 310 can determine that an object (such as a user’s head) is in close proximity to the side of the hair styler 1 that contains UWB sensor 320b. Furthermore, depending on the amplitude of the reflected UWB, the processor 314 of the computing device 310 may assume that said object is the side of a user’s head. Additionally, or alternatively, based on the power (amplitude) of the reflected UWB signal (which as indicated above may be dependent on the size of the surface area off of which the pulses 330a, 330b reflect), and the distance that the object is from the sensor the processor 314 of the computing device 310 may use the pulses 330a, 330b to generate amplitude-distance profiles that graphically depict the distance of objects and their relative size with respect to the UWB sensors 320a, 320b of the hair styler 1. Figure 5b depicts signal amplitude-distance graphs of the reflected UWB signals received at the UWB sensors 320a, 320b in the scenario shown in Figure 5a. As shown in Figure 5b (top) the reflected signal 350b received at the UWB sensor 320b has a large amplitude at a small distance from the UWB sensor 320b that tapers off over distance. Such a reflected signal 350b received at the UWB sensor 320b indicates that there is a large object (e.g., the user’s head 340) in close proximity to the sensor 320b. Conversely, the reflected signal 320a (Figure 5b; bottom) received at the UWB sensor 320a has a consistently small amplitude, with a small bump in amplitude at a mid distance from the UWB sensor 320a. Such a reflected signal 350a received at the UWB sensor 320a indicates that there are no objects (or at the most very small objects only) in proximity to the sensor 320a. Based on those signal amplitude-distance graphs (and / or their corresponding data), the processor 312 of the computing device 320 of the hair styler 1, can determine a side of the hair styler 1 that is in close proximity to the user’s head 340. Furthermore, based on those signal amplitude-distance graphs (and / or their corresponding data) and the determined orientation of the hair styler 1, the processor 312 can also determine movements of the hair styler 1 relative to the user’s head. In one example, having determined that the right-hand side of the hair styler 1 is in close proximity to the user’s head 340, the processor 312 may continue to process incoming reflected UWB radio signals to determine movements of the hair styler 1 with respect to the user’s head 340. For example, as the user rotates the hair styler 1 to curl their hair, the position of the UWB sensor 320b relative to the user’s head 340 will change, altering the reflected radio UWB signals detected by that sensor. The processor 312 can process the signals from the UWB sensors 320 to determine if the user is rotating the hair styler 1 clockwise or anticlockwise. This information can also be determined from the signals obtained from the accelerometer and / or the gyroscope. Beneficially, by determining the orientation of the hair styler 1, as well as which side of the hair styler 1 is close to a user’s head 340, the processor 312 of the hair styler 1 can determine whether a user is correctly using the hair styler 1 to achieve a desired style. For example, where a user has input, via a user interface 324 of the hair styler 1, a desired style to be achieved, the processor 312 may compare expected movements for achieving the selected style stored in the memory 314 of the computing device 310, with determined movements of the hair styler 1. Based on that comparison, the processor 312 may trigger the feedback module 322 of the hair styler 1 to provide appropriate feedback to a user. Additionally, pressure sensors may be located in the hair styler 1 to sense when pressure is applied to the hair styler i.e., when the hair styler 1 is being held. For example, one or more pressure sensors may be provided in the hair styler 1 in proximity to the location of the UWB sensors 320a, 320b. Beneficially, by using such one or more pressure sensors, the processor 312 is able to take account of reflected UWB signals that arise due to the presence of the user’s hand to ensure that user hand placement on the hair styler 1 is not falsely attributed to head position. For example, where it is determined that a user is holding the hair styler 1 in a region proximal to the UWB sensors 320a, 320b, the processor 312, when processing the reflected UWB signal(s) may apply corrections to account for features in the signals that arise from hand positioning. By way of example only, where the processor uses the reflected UWB signals to generate amplitude-distance profiles, the processor may discount, attenuate, dampen, or filter out one or more features of the amplitude-distance profile that occur at a very short distance from the UWB sensors 320a, 320b e.g., a few mm. Figures 5c &5d illustrate an example movement of the hair styler 1 and the feedback that can be provided. In Figure 5c, having determined the orientation of the hair styler 1, as well as which side of the hair styler 1 is close to the user’s head 340, the processor 312 continues to process the incoming reflected UWB signals and / or the signals from the accelerometer or the gyroscope to determine if the hair styler 1 is being rotated by the user in a clockwise rotation with respect to the user’s head 340, as described above. In the example of Figure 5c, the user is rotating the hair styler 1 in the clockwise direction and the processor 312 compares that motion / movement with sets of movements that are expected or that should be performed by the user to achieve the desired style selected by the user. For example, the sets of movements that should be performed may be stored in the memory 314 of the computing device 310 of the hair styler 1 (or alternatively they may be downloaded from the Internet in response to a user selecting a desired style via a user interface of the hair styler 1) to determine whether the movement is a correct movement for the style desired. Having determined that the movement is correct, the processor 312 may trigger (e.g., via a feedback command, or other appropriate message) the feedback module 322 to provide appropriate feedback to the user (e.g., vibrations, sounds, a visual indication, or the like), or alternatively, as the movement is correct, the processor 312 may not trigger any type of feedback (as shown in Figure 5c) If, however, the processor 312 determines that the hair styler 1 is being rotated by the user in an anti-clockwise direction with respect to the user’s head 340, when it should be rotated in a clockwise direction, then the processor 312 may trigger the feedback module 322 (e.g., via a feedback command, or other appropriate message) to provide appropriate feedback to the user (e.g., vibrations, sounds, a visual indication, or the like) so that they know that they are rotating the device in the wrong direction and can change the direction of rotation accordingly. In yet another example (as shown in Figure 5d) having determined that the hair styler 1 is being rotated by the user in the correct clockwise direction with respect to the user’s head 340, the processor 312 continues to monitor the rotation and outputs feedback to the user when the user has rotated the hair styler 1 through an optimum angle of rotation with respect to the user’s head. For example, as shown in Figure 5d, the hair styler 1 vibrates (“buzzes”) when the hair styler 1 has been rotated to the optimal angle with respect to the user’s head to achieve the desired level or amount of curl for the tress of hair in the hair styler 1. It will be appreciated that the movement / motion detections and corresponding feedback described above are given by way of example only and that other motions and feedback combinations are possible. The processes of determining movements of the hair styler 1 and providing appropriate feedback as outlined above will now be described further with respect to the flow chart of Figure 6. As shown, at step S602, a user of the hair styler 1 inputs, into a user interface of the hair styler 1, a desired hair style that they wish to achieve. For example, the user may select a particular type of hair style that they wish to achieve from a list of preprogrammed styles stored in a memory of the hair styler 1. In such a scenario, the memory of the hair styler 1 (or alternatively a computing device in communication with the hair styler 1) may store sets of movements / motions that must be performed with the hair styler 1 to achieve a specific type of hair style e.g., the hair styler 1 may need to be rotated in a clockwise manner with respect to a user’s head to achieve curls that curl in a particular direction with respect to the user’s head. Alternatively, or additionally, the processor 312 of the hair styler 1 may be configured to download sets of movements / motions that must be performed with the hair styler 1 to achieve a specific type of hair style from the Internet in response to a user selecting a particular type of hair style that they wish to achieve via the user interface of the hair styler 1. At step S604, the processor 312 determines the orientation of the hair styler 1. As previously described, the microprocessor 312-1 in communication with the orientation module 316 of the hair styler 1 may request and collect data from at least one of a magnetometer 316-2, or a gyrometer 316-3, or an accelerometer 316-4 to determine an orientation of the hair styler 1 with respect to a predefined frame of reference. At step S606, the UWB sensors 320a, 320b emit UWB pulses 330a, 330b. Those pulses may be pulses with a bandwidth of at least 500 MHz or greater. The pulses may be emitted repeatedly over a time period AT. At step S608, the UWB sensors 320a, 320b detect reflected UWB radio signals that arise through reflection of the emitted UWB pulses 330a, 330b. The reflected UWB radio signals comprise a linear combination of reflected radio pulses that are reflected off different objects in the vicinity of the UWB sensor. At step S610, the processor 312 processes those detected reflected UWB radio signals to determine amplitude distance information for the reflected signals corresponding to the above-described amplitude-distance signal graphs. The processor may also track distance information for selected objects found in the reflected USB signals and monitor how the distance changes with time. For example, the processor 312 (at step S611) may generate a signal graph (such as an amplitude-distance graph using the ToA information (T), also referred to as Time of Flight (ToF) information and using the amplitude information (ani)) for each of the detected reflected UWB radio signals detected by the UWB sensors 320a, 320b respectively over a pre-determined period of time to map out changes in the detected reflected UWB radio signals over time. It will be appreciated that the processor does not actually need to draw out the signal graphs visually and instead will store the data in 2D data structures within the memory of the processor 312. At step S612, the processor 312 analyses the UWB data in the memory (i.e. the signal graph data such as amplitude-distance graphs, distance-time graphs, and the like), to determine whether a side of the hair styler 1 is proximal to the user’s head. Based on determining that the user’s head is in the vicinity of the UWB sensor 330b, in combination with the determined orientation of the hair styler 1 made at step S604, the processor 312 can determine which side of the user’s head the hair styler 1 is likely to be on. Based on determining that the user’s head is in the vicinity of the UWB sensor 330b, in combination with the determined orientation of the hair styler 1, the processor 314 can determine that the hair styler 1 is most likely to be on the left-hand side of the user’s head. If the styler 1 had been upside down in comparison to the orientation shown in Figure 5a, then the styler 1 would most likely be on the right-hand side of the user’s head. It is most likely to be on this side because it is most likely that the user will always hold the styler with the handle portion pointing out in front of themself. In particular, it is most likely that the user in Figure 5a is looking into the page and the handle of the hair styler is pointing into the page. It would be very difficult for the user to hold the styler 1 with the handle pointing in the opposite direction out of the page whilst styling their hair. So, it is reasonable to assume that holding the styler in such an orientation would not be done in practice. Hence, based on the orientation of the styler 1 and which one of the UWB sensors 320 detects the user’s head, the processor 312 can determine whether the styler 1 is on the left or the right-hand side of the user’s head. At step S614, the processor 312 of the hair styler 1 re-determines the orientation of the hair styler to detect changes in its orientation e.g., to determine whether the hair styler 1 is being moved / used by a user. For example, as previously described, the microprocessor 312-1 in communication with the orientation module 316 of the hair styler 1 may request and collect data from at least one of a magnetometer 316-2, or a gyrometer 316-3, or an accelerometer 316-4 to determine the orientation of the hair styler 1 with respect to a reference frame. At step S616, the processor 312, based on the determined changes in orientation of the hair styler 1, determines whether the change in orientation (i.e., a movement of the hair styler 1 by the user) is a correct movement necessary to achieve the desired hair style input by the user at step S602. For example, the processor 312 may compare the movement with sets of movements stored in the memory 312, or downloaded from the Internet, that are necessary to achieve a desired hair styler input by the user e.g., the hair styler 1 may need to be rotated in a clockwise manner with respect to a user’s head to achieve curls that curl in a particular direction with respect to the user’s head. At step S618, the processor 312, based on determining whether the change in orientation ( / .e., a movement of the hair styler 1 by the user) is a correct movement to achieve the desired hair style input by the user at step S602, triggers appropriate feedback. For example, the processor 312 may be configured to send a feedback command to the feedback module 322 to provide audio, visual, and / or haptic feedback as appropriate. By way of example only, having determined that the user is rotating the hair styler 1 in the wrong direction, the processor 312 may be configured to send a feedback command to the feedback module 322 to provide feedback to the user to indicate they are making a mistake. Having provided feedback, the process 600 may end, or alternatively it may operate on a loop such that after having provided the feedback the processor 312 returns step S614 to re-determine the orientation of the hair styler 1 again. Figure 7a illustrates another example of the hair styler 1 in use. In this example, the user places a tress of hair in the styler 1 and then moves the styler in the direction illustrated away from the user’s head along the tress of hair. Figures 7b and 7c depict signal amplitude-distance graphs obtained from the UWB sensor 320b as the hair styler 1 is moved along the tress of hair. Specifically, the upper plots of Figures 7c and 7d show the UWB signals received by the sensors 320a and 320b respectively at time T1 when the styler is close to the user’s head at the start of the hair tress being styled; and the lower plots of Figures 7c and 7d show the UWB signals received by the sensors 320a and 320b respectively at time T2 when the styler 1 is further away from the user’s head towards the end of the hair tress being styled. As shown in Figure 7b (top) the reflected signal 330b received at the UWB sensor 320b at time T1 has a large amplitude at a small distance from the UWB sensor 320b that tappers off over distance. Such a reflected signal 330b received at the UWB sensor 320b indicates that there is a large object (e.g., the user’s head 340) in close proximity to the sensor 320b. Conversely, the reflected signal 320a (Figure 7c; top) received at the UWB sensor 320a has a consistently small amplitude, with a small bump in amplitude at a mid-distance from the UWB sensor 320a. Such a reflected signal 350a received at the UWB sensor 320a indicates that there are no objects (or at the most very small objects) in proximity to the sensor 320a. Based on these amplitude-distance graphs (and / or their corresponding data) and the determined orientation of the hair styler 1, the processor 312 of the computing device 320 of the hair styler 1, can determine that the right-hand side of the hair styler 1 is in close proximity to the left-hand side of user’s head 340. As shown in Figure 7b (bottom) the reflected signal 350b received at the UWB sensor 320b at time T2 has a somewhat large amplitude (smaller than that in Figure 7a (top)) at a mid-distance from the UWB sensor 320b that tapers off over distance. Such a reflected signal 350b received at the UWB sensor 320b indicates that there is a large object (e.g., the user’s head 340) in at a mid-distance from the sensor 320b. Conversely, the reflected signal 320a (Figure 7c; bottom) received at the UWB sensor 320a has a consistently small amplitude, with a small bump in amplitude at a mid-distance from the UWB sensor 320a. Such a reflected signal 350a received at the UWB sensor 320a indicates that there are no objects (or at the most very small objects only) in proximity to the sensor 320a. Based on these amplitude-distance graphs (and / or their corresponding data) and the determined orientation of the hair styler 1, the processor 312 of the computing device 320 of the hair styler 1, can determine that the right-hand side of the hair styler 1 is facing towards the left-hand side of user’s head 340 but is slightly further away than it was at time T1. By comparing the amplitude-distance graphs (or the data / information associated with them) shown in both Figure 7b and 7c, the processor 312 of the hair styler 1 can determine that the hair styler 1 is in use and that it is being moved in a direction away from the user’s head. Furthermore, by measuring how far the peak in the amplitudedistance graphs of Figure 7b has moved over time, the processor 312 can also determine the speed at which the user is moving the hair styler 1 away from their head. For example, the speed at which the user is moving the hair styler 1 away from their head may be calculated by: ARangepeak ---— = speed wherein ARangePeak is the change in position of the peak in the amplitude-distance graphs, AT is the time period over which the reflected UWB signals where received (i.e., T2 - T1 in the example given in Figures 7b &7c). Beneficially, by determining the speed at which the hair styler 1 is being moved away (or toward) a user’s head i.e., how quickly tresses of hair are being passed through the hair styler 1, the processor 312 may trigger the feedback module 322 of the hair styler 1 to provide appropriate feedback to a user if the speed is too excessive or not sufficient enough to achieve a desired style. The value of ARangepeak may also give a crude indication of the length of the user’s hair. Specifically, during use the user will repeatedly move the styler along tresses of hair and once the tress of hair has passed through the styler 1, the user will move the styler 1 closer to the user’s head again to style the next tress of hair. Therefore, by monitoring the average value of ARangepeak, the processor 312 can determine an approximate length of the user’s hair. This information may be used, for example to control the application of heat by the heaters to the hair. For example, less heat may be applied to the hair near the roots and more heat may be applied towards the end of the tress. The length of the tress may be used to define how the power will be varied along the tress. The processes of determining the speed of movement of the hair styler 1 and providing appropriate feedback as outlined above will now be described further with respect to the flow chart of Figure 8. Figure 8 illustrates another process flow chart of the steps involved in providing feedback to a user. At step S802, a user of the hair styler 1 inputs, into a user interface of the hair styler 1, a desired hair style that they wish to achieve. For example, the user may select a particular type of hair style that they wish to achieve from a list of pre-programmed styles stored in a memory of the hair styler 1. In such a scenario, the memory of the hair styler 1 (or alternatively a computing device in communication with the hair styler 1) may store sets of movements / motions that must be performed with the hair styler 1 to achieve a specific type of hair styler e.g., the hair styler 1 may need to be rotated in a clockwise manner with respect to a user’s head to achieve curls that curl in a particular direction with respect to the user’s head. The sets of movements / motions that must be performed with the hair styler 1 to achieve a specific type of hair style may also include durations such as the duration needed for a tress of hair to be in the hair styler 1 to achieve the desired hair style, and / or the speed at which the tress of hair should be run through the hair styler 1. Alternatively, or additionally, as already described above, the processor 312 of the hair styler 1 may be configured to download sets of movements / motions and / or durations such as the duration needed for a tress of hair to be in the hair styler 1 to achieve the desired hair style, and / or the speed at which the tress of hair should be run through the hair styler 1 from the Internet in response to a user selecting a particular type of hair style that they wish to achieve via the user interface of the hair styler 1. At step S804, the processor 312 determines the orientation of the hair styler 1 in the manner described above. At step S806, the UWB sensors 320a, 320b emit UWB pulses 330a, 330b. At step S808, the UWB sensors 320a, 320b detect, at time T1, a first set of reflected UWB radio signals that arise through reflection of the emitted UWB pulses 330a, 330b. At step S810, the UWB sensors 320a, 320b detect, at time T2, a second set of reflected UWB radio signals that arise through reflection of the emitted UWB pulses 330a, 330b. It will be appreciated that the UWB sensors 320a, 320b may also detect a third, fourth etc., set of reflected UWB radio signals at times T3, T4, etc. At step S812, the processor 312 processes the detected reflected UWB radio signals detected at T1, T2, (and T3, T4, etc., where appropriate). The processor 314 may be configured to use those detected reflected UWB radio signals (and / or information pertaining to those detected reflected UWB radio signals) to generate (step S813) signal graphs such as amplitude-distance graphs, distance-time graphs, and the like, for each of the detected reflected UWB radio signals detected by the UWB sensors 320a, 320b detected at T1, T2, (and T3, T4, etc., where appropriate). For example, the processor 312 may generate a signal graph (such as an amplitudedistance graph using ToA information, also referred to as Time of Flight (ToF) information) for each of the detected reflected UWB radio signals detected by the UWB sensors 320a, 320b respectively at T1, T2, (and T3, T4, etc., where appropriate) to map out changes in detected reflected UWB radio signals overtime. At step S814, the processor 312 analyses the signal graphs (such as amplitude-distance graphs, distance-time graphs, and the like) for the detected reflected UWB radio signals detected by the UWB sensors 320a, 320b at T1, to determine whether a user’s head is on the right- or left-hand side of the hair styler 1. For example, as previously described with reference to Figures 5a and 5b, analysis of the signal graphs associated with the detected reflected UWB radio signals detected by the UWB sensors 320a, 320b respectively may result in the processor 314 determining that an object (e.g., the user’s head) is in the vicinity of the UWB sensor 330b, but not in the vicinity of UWB sensor 330a. Based on determining that the user’s head is in the vicinity of the UWB sensor 330b, in combination with the determined orientation of the hair styler 1 made at step S804, the processor 312 determines what side of the user’s head the hair styler 1 is on. For example, as shown previously with reference to Figure 5a, based on determining that an object (e.g., the user’s head) is in the vicinity of the UWB sensor 330b, in combination with the determined orientation of the hair styler 1, the processor 314 can determine that the right-hand side of the hair styler 1 is most likely on the left-hand side of the user’s head. Additionally, based on the analysis of the signal graphs (such as amplitude-distance graphs, distance-time graphs, and the like) for the detected reflected UWB radio signals detected by the UWB sensor 320b at T1, the processor 312 also determines a distance of the user’s head from the UWB sensor 320b. At step S816, the processor 312 analyses the signal graphs (such as amplitude-distance graphs, distance-time graphs, and the like) for the detected reflected UWB radio signals detected by the UWB sensors 320a, 320b at T2, to determine whether the right-hand side of the hair styler 1 is still on the left hand side of the user’s head in the same manner as described above. Additionally, based on the analysis of the signal graphs (such as amplitude-distance graphs, distance-time graphs, and the like) for the detected reflected UWB radio signals detected by the UWB sensor 320b at T2, the processor 312 also determines a distance of the user’s head from the UWB sensor 320b. At step S818, the processor 312 compares the determined distance of the user’s head from the UWB sensor 320b at T1 and the determined distance of the user’s head from the UWB sensor 320b at T2. For example, the processor 312 may determine the difference in the distance of the user’s head the UWB sensor 320b between times T1 and T2 and divides the distance by the time difference T2-T1, to determine a measure of the speed of movement of the hair styler 1 along the tress, as described above. At step S820, the processor 312, based on the determined speed of movement of the hair styler 1, determines whether the speed is appropriate / correct to achieve the desired hair style input by the user at step S802. For example, the processor 312 may compare the determined speed of the movement with speeds of movements stored in the memory 312, or downloaded from the Internet, which are desirable to achieve the desired hair style input by the user. At step S822, the processor 312, based on determining whether the speed of the movement is appropriate / correct to achieve the desired hair style, triggers appropriate feedback. For example, the processor 312 may be configured to send a feedback command to the feedback module 322 to provide audio, visual, and / or haptic feedback as appropriate. By way of example only, having determined that speed of movement of the hair styler 1 is inappropriate to achieve the desired style, the processor 312 may be configured to send a feedback command to the feedback module 322 to provide feedback to the user to indicate they are making a mistake - such as moving the styler 1 too slowly or too quickly the tress of hair. Alternatively, the speed information may be used to control the heating of the heaters. For example, if the speed is higher than required, then the power supplied to the heaters may be increased so that the required heat energy can be applied to the tress of hair to allow the tress to be styled. Alternatively, if the speed is lower than required, then the power delivered to the heaters may be reduced so that the user does not overheat or damage their hair. Having provided feedback or varied the power delivered to the heaters, the process 800 may end, or alternatively it may operate on a loop such that after having provided the feedback the processor 312 returns step S806 to transmit another set of UWB pulses from the UWB sensors. Modifications and Alternatives Detailed embodiments have been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above embodiments whilst still benefiting from the inventions embodied therein. By way of illustration only a number of these alternatives and modifications will now be described. For the purposes of simplicity, the above description focuses on hair care products and particularly a hair styling device. However, it will be appreciated that the abovedescribed concepts may be applied widely to any hair styling product including, for example: hair dryers, curling tongs / wands, hair straighteners, crimpers, etc. In the above examples, the feedback messages were provided to the user by way of the user interface on the beauty product device or on the processing device. This is not essential. The feedback messages may be provided by any suitable user interface of any nearby device. For example, they may be sent to an Amazon Echo speaker device for playout to the user as voice messages or displayed to the user on a television screen, smart phone screen, smart mirror or the like. The method of communication between the hair styler and any external computing device could be via a cable or wireless means. Examples of applicable wireless communications include Bluetooth, Wi-Fi, LoRa, ZigBee, 802.15 standard, NFC, or optical means - both visible and IR. In the examples given above, various specific temperatures and power levels were discussed. As those skilled in the art will appreciate, all these specific values are clearly not essential to the invention and any particular values used in a given product will depend on the treatment to be given, the voltage sources used etc. In the above embodiments, a number of software modules were described. As those skilled in the art will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied to the hair styler or the corresponding processing device (mobile telephone and / or the like) as a signal over a computer network, or on a recording medium. Further, the functionality performed by part or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software is preferred as it facilitates the updating of the beauty product device (and the processing device). Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

Claims

1. A hair drying and / or styling device comprising:a first ultra-wide band, UWB, sensor located on the hair drying and / or styling device for transmitting UWB radio pulses and for receiving UWB radio signals reflected by objects in the vicinity of the first UWB sensor; anda processor in communication with the first UWB sensor and configured to:i) process signals obtained from the first UWB sensor to detect when the hair drying and / or styling device is in proximity to a user’s head; andii) perform a control action in response to detecting that the hair drying and / or styling device is in proximity to a user’s head.

2. The hair drying and / or styling device of claim 1, wherein the control action comprises providing feedback to the user.

3. The hair drying and / or styling device of claim 2, wherein the feedback provided to the user comprises at least one of: audio feedback, visual feedback, and / or haptic feedback.

4. The hair drying and / or styling device of any preceding claim, wherein the control action comprises controlling a power delivered to at least one heater of the hair drying and / or styling device.

5. The hair drying and / or styling device of any preceding claim, wherein the hair drying and / or styling device further comprises:a second UWB sensor, the first and the second UWB sensors being located on either side of the hair drying and / or styling device; andthe processor is in communication with the first and second UWB sensors and configured to:process signals obtained from the first and second UWB sensors to detect a side of the hair drying and / or styling device on which a user’s head is located.

6. The hair styling device of claim 5, wherein the processor is configured to:compare the signals obtained by the first and the second UWB sensors to determine which of the signals has the largest amplitude peak; anddetermine, based on which of the signals has largest amplitude peak, which side of the hair drying and / or styling device on which a user’s head is located.

7. The hair styling device of claim 6, wherein the user’s head is determined to be on the side of the hair styler device corresponding to the side on which the UWB sensor that received the signal with the largest amplitude peak is located.

8. The hair styling device of claim 6 or claim 7, wherein to compare the signals obtained by the first and the second UWB sensors comprises:generating, for each of the signals obtained by the first and the second UWB sensors, a distance-amplitude graph; andanalysing each distance-amplitude graph to identify which of the distanceamplitude graph contains the largest amplitude peak.

9. The hair styling device of any preceding claim, wherein the hair styling device further comprises:a pressure sensor located proximal to the first and / or the second UWB sensor; andwherein, the processor is further configured to:determine, based on data obtained from the pressure sensor, whether a user’s hand is positioned proximal to the first and / or second UWB sensor; andin response to determining that the user’s hand is proximal to the first and / or second UWB sensor, applying a correction to the signals obtained from the first and / or UWB sensor to account for UWB radio signals reflected off the user’s hand.

10. The hair drying and / or styling device of any preceding claim, wherein theprocessor is further configured to:determine an orientation of the hair drying and / or styling device with respect to magnetic north.

11. The hair drying and / or styling device of claim 10, wherein the processor is in communication with orientation sensing circuitry configured to sense an orientation of hair drying and / or styling device, and wherein the processor is configured to:process data received from the orientation sensing circuitry to determine an orientation of the hair drying and / or styling device with respect to magnetic north.

12. The hair drying and / or styling device of claim 11, wherein the orientation sensing circuitry comprises at least one of: an accelerometer, a gyrometer, and / or a magnetometer.

13. The hair drying and / or styling device of any one of claims 10-12, wherein the processor is configured to:perform a control action in response to determining the orientation of the hair drying and / or styling device and detecting that the hair drying and / or styling device is in proximity to a user’s head.

14. The hair styling device of any one of claims 10-13, wherein the computing device further comprises:a user interface for selection of a desired hair style by a user, and wherein the processor is further configured to:determine movement of the hair styling device;compare the determined movement with a set of movements necessary to achieve the desired hair style to determine whether the movement is correct to achieve the desired hair style; andperform a control action based on the determination of whether the movement is correct to achieve the desired hair style.

15. The hair styling device of claim 14, wherein to determine movement of the hair styling device, the processor is configured to:re-determine the orientation of the hair styling device;compare the orientation and the re-determined orientation of the hair styling device; anddetermine, based on the comparison, a movement of the hair styler device.

16. The hair drying and / or styling device of one of claims 13-15, wherein the control action comprises providing feedback to the user.

17. The hair drying and / or styling device of claim 16, wherein the feedback provided to the user comprises at least one of: audio feedback, visual feedback, and / or haptic feedback.

18. The hair drying and / or styling device of one of claims 13-15, wherein the control action comprises controlling a power delivered to at least one heater of the hair drying and / or styling device.36

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