Appliance with sensor

Abstract

An appliance is described that includes a main unit to which one of a plurality of accessories is attachable, a sensor operable to emit emissions and receive reflected emissions, and a control module. The control module is operable to determine which of the plurality of accessories is attached to the main unit based on the data output by the sensor.

Description

Technical Field

[0001] The present invention relates to an appliance having a sensor for sensing an accessory. Background Art

[0002] Some appliances may include many different attachments. For example, a hair appliance may include different attachments to achieve different styling effects. In some cases, the appliance may need to determine which attachment is in use. Summary of the invention

[0003] The present invention provides an appliance comprising: a main unit to which one of a plurality of accessories can be attached; a sensor operable to emit a projection and receive a reflected projection; and a control module operable to determine which of the plurality of accessories is attached to the main unit based on data output by the sensor.

[0004] By using sensors, such as time-of-flight sensors, the control module is able to remotely determine which accessory (if any) is in use. In addition to such sensors, the appliance may also conceivably include alternative means for determining which accessory is in use. For example, the main unit may include electrical contacts or mechanical switches, and when attached, each accessory may contact a different set of contacts or actuate a switch of a different arrangement. In another example, the main unit may include one or more Hall effect sensors, and each accessory may include a unique arrangement of magnets. In each of these examples, the contacts, switches, or sensors will need to be located at the interface with the accessory. However, it may be challenging to package additional components at the interface of the main unit. For example, there may not be enough space for components and / or required wiring, or the conditions of the path taken by the interface and / or wiring may be harsh (e.g., high temperature). By using sensors that are operable to emit emitting objects and receive reflected emitting objects, such as time-of-flight sensors, the sensors can be positioned away from the accessories and thus away from the interface. As a result, the packaging of the sensors and the wiring of the cables become easier. In addition, the sensors are able to remotely sense different accessories without providing additional components, such as RFID tags, etc., for the accessories. Thus, different accessories may be remotely sensed in a relatively cost-effective manner.In an example, the sensor may be a time-of-flight sensor.In an example, the emission may include electromagnetic radiation.

[0005] The appliance may include an electrical component, and the control module is operable to control the electrical component in response to the determination. Thus, the control module is able to control the electrical component differently for different accessories. This has the advantage that operation of the appliance can be automatically controlled depending on the accessory being used. In some examples, the control module is operable to control input power to the electrical component in response to the determination.

[0006] The electrical component may be an electric motor or a heater, and the control module may be operable to control the speed of the electric motor or the temperature of the heater in response to the determination. The performance of the appliance may be improved by operating the electric motor at different speeds and / or by operating the heater at different temperatures based on the attachment in use. For example, the appliance may be a hair appliance, the electric motor may be used to generate the airflow, and the heater may be used to heat the airflow. Different attachments may provide better drying or styling results at different flow rates and / or different heat settings. In another example, the appliance may be a vacuum cleaner, and the electric motor may be used to generate suction. Different attachments may perform better at different suctions.

[0007] The appliance may include an airflow generator for inhaling an airflow through the appliance, and the control module may be operable to control the characteristics of the airflow in response to the determination. Different attachments may provide better results for different airflows. For example, the appliance may be a hair appliance, and the attachment may include a diffuser and a concentrator. A diffuser may provide better results when the airflow has a lower flow rate. This is because the airflow moves the hair less, thus better defining the curls. In contrast, a concentrator may provide better results when the airflow has a higher flow rate. For example, by adopting a higher flow rate, drying and / or styling of hair may be achieved more quickly. In another example, the appliance may be a vacuum cleaner, and the attachment may include a first suction nozzle for floors and a second suction nozzle for upholstery. When used for floors, a higher suction force may be conducive to inhaling more dust. However, when used for upholstery, a higher suction force may cause upholstery to be sucked in and clog the suction nozzle. Therefore, better results may be obtained on upholstery with a lower suction force.

[0008] The control module is operable to control one or more of the flow rate and temperature of the airflow. As described in the previous paragraph, different attachments may provide better results for different flow rates. Additionally or alternatively, different attachments may provide better results for different temperatures. For example, the appliance may be a hair appliance, and at least one attachment may provide better styling results at a lower heat setting, and at least one attachment may provide better styling results at a higher heat setting. By controlling the flow rate and / or temperature of the airflow in response to the attachment being used, a better overall result may be obtained.

[0009] The appliance may be a hair appliance including a plurality of flow and heat settings, and the control module may be operable to select one of the settings based on the determination. As described above, different attachments may provide better results for different flow and / or heat settings. Thus, by selecting one of a plurality of settings based on the attachment in use, a better drying and / or styling effect may be achieved.

[0010] The appliance may include a plurality of accessories. In addition, each accessory may include a portion configured to reflect an emission toward a sensor when attached to the main unit, the sensor being operable to receive an emission emitted by the sensor and reflected by the portion of the accessory when attached to the main unit, and the accessories may be different such that the emission reflected by the portion of each accessory is different. This then represents a relatively cost-effective way of determining which accessory is attached to the main unit. In particular, the differentiation of accessories may be achieved by using relatively simple differences in the portions. In some examples, the portions may differ in size, shape, surface features, reflectivity, or any other feature that changes the way an emission is reflected by the portions. In an example, the portions may differ in the wavelength or wavelength range of electromagnetic radiation reflected by the portions (e.g., different colors), and the sensor being operable to sense the wavelength or wavelength range of the received emission (e.g., the color of the received emission).

[0011] The sensor is operable to sense the time of flight of a projectile. For example, the sensor may be provided by a time of flight sensor. The protrusion of the portion toward the sensor may be different for different accessories. For example, the accessories may differ in the extent to which the portion protrudes toward the sensor. For example, a portion of each of a plurality of accessories may include a protrusion that protrudes toward the sensor when the accessory is attached to the main unit. The protrusions may have different sizes so that when attached to the main unit, the protrusion of each accessory protrudes toward the sensor by a different amount. Therefore, the distance between the sensor and the protrusion is different for different accessories. This is then reflected in the data output by the sensor, which the control module uses to determine which accessory (if any) is attached to the main unit. As another example, the accessory may differ in the pattern or shape according to which the portion protrudes toward the sensor. For example, the portion may include a plurality of (e.g., an array) of protrusions. Each protrusion may protrude toward the sensor by a certain amount, and in doing so, the identity of the accessory may be encoded. For example, this may be similar to a barcode. The protrusion pattern may be different for different accessories. The set or pattern of distances of the protrusions from the sensor for a given part is then reflected in the data output by the sensor, which the control module can then use to determine which accessory, if any, is attached to the main unit. For example, the control module can map the set or pattern of distances to one of a plurality of patterns, each pattern being associated with a different accessory, to determine which accessory is attached to the main unit.

[0012] The sensor is operable to sense the intensity of the reflected emission, and the reflectivity of the portion may be different for different accessories. The reflectivity may be a measure of the extent to which a surface reflects an incident emission (e.g., radiation). For example, a time-of-flight sensor may be used to sense the intensity of the reflected emission, as well as the time of flight of the emission. As another example, the sensor may include a detector configured to detect the intensity of the reflected emission, but not necessarily the time of flight of the emission. The reflectivity of the portion may be different for different accessories. Therefore, the intensity of the emission reflected from the portion and received by the sensor may be different for different accessories. This may then be reflected in the data output by the sensor, which the control module uses to determine which accessory, if any, is attached to the main unit. The different reflectivities may be provided by, for example, different surface textures or finishes, material transparency, and / or any other features or properties that affect the extent to which an emission is reflected by the portion to the sensor.

[0013] The protrusion of each accessory may include a translucent material, and the transparency of the translucent material may be different for different accessories. Therefore, the reflections reflected by the protrusions may have different characteristics for different accessories, which in turn may be used to determine which accessory (if any) is attached to the main unit.

[0014] At least one accessory can be attached to the main unit in any of a plurality of rotational positions around the axis of the main unit. For example, when attached, at least one accessory can rotate freely relative to the main unit around an axis, such as the central longitudinal axis of the barrel of the main unit. The attachment of the accessory in any of a plurality of rotational positions can allow the user to achieve the desired airflow direction and angle without having to hold or manipulate the appliance at an uncomfortable angle. When at least one accessory is attached to the main unit, the control module is operable to additionally determine the rotational position of at least one accessory relative to the main unit. This allows the control module to determine the rotational position of the accessory. This in turn can allow the control module to control the appliance according to the determined rotational position. For example, this may have the benefit that the operation of the appliance can be automatically controlled based on the rotational position of the accessory relative to the main unit. For example, the appliance may include an electrical component (e.g., a heater and / or an airflow generator), and the control module is operable to control the electrical component in response to the rotational position determination. For example, the user can manually change the rotational position of the accessory relative to the unit, thereby providing a means by which the user can control the appliance to operate in a specific mode. As another example, accessories oriented in different rotational positions relative to the main unit (and therefore relative to, for example, the handle of the main unit) may provide optimal styling when the appliance is operated differently. Thus, this may provide improved styling. The control module may be operable to simultaneously determine the accessory and the rotational position of the accessory.

[0015] The appliance may include at least one accessory that may be configured to reflect a projectile toward the sensor when the accessory is attached to the main unit, and the sensor may be operable to receive a projectile emitted by the sensor and reflected by the accessory when the accessory is attached to the main unit. When the accessory is attached to the main unit, the at least one accessory may include a plurality of portions distributed about an axis, and each of the plurality of portions may reflect a projectile to the sensor differently. Different portions distributed about the axis reflecting projectiles differently allows the control module to determine the rotational position of the accessory in a simple and cost-effective manner. In some examples, the portions may differ in size, shape, protrusion toward the sensor, a pattern in which the portions protrude toward the sensor, surface features, reflectivity, or any other feature that changes the way projectiles are reflected by the portions.

[0016] The sensor can be configured to emit a projectile toward a reference rotational position about an axis, and the rotational position of at least one accessory can be determined based on the projectile reflected by one or more portions at the reference rotational position. This can allow for a relatively simple and cost-effective way to provide determination of the rotational position. For example, the sensor can emit a projectile toward the reference rotational position, and can receive a projectile reflected by any portion of the accessory located at the reference rotational position. Since different portions reflect projectiles differently, the portion located at the reference rotational position will be encoded in the reflected projectile received by the sensor, and thus encoded into the data output by the sensor. The control module can then determine the rotational position of the accessory based on the output data. For example, the control module can store a mapping of different output data (encoding different portions of the accessory) to different rotational positions. The control module can match the current output data with one of the stored output data, thereby determining the rotational position corresponding to the current output data through the mapping.

[0017] The sensor may include a two-dimensional array of receivers operable to receive emissions emitted by the sensor and reflected by one or more portions of the accessory when attached to the main unit. This may allow for accurate rotational position determination and / or flexibility in enabling multiple portions of at least one accessory. For example, while a single receiver may allow for determining the distance or reflectivity of a portion of an accessory, a two-dimensional array of receivers may (alternatively or additionally) allow for determining the position of a portion of the accessory in a plane. For example, at least one accessory may include a first portion and a second portion distributed around an axis of rotation, the first portion configured to reflect emissions to the sensor, and the second portion configured to reflect emissions to the sensor differently from the first portion (including, for example, not reflecting emissions at all). When the accessory is rotated and the first portion is in different rotational positions accordingly, different receivers in the two-dimensional array of receivers may receive emissions reflected by the first portion differently. For example, different receivers may receive reflected emissions of different intensities and / or have different times of flight. For example, a receiver located closest to the first portion may receive the most reflected emissions from the first portion and / or have the shortest time of flight. In any case, reflected emissions received differently at different receivers may encode the rotational position of the first portion about the axis, and the control module may determine the rotational position of the accessory accordingly based on data output by the sensor.

[0018] The surface of the main unit may include an anti-reflective component configured to reduce the extent to which the emission is reflected from the surface of the main unit. This can reduce the extent to which the emission is reflected from one or more surfaces of the main unit, and thus can reduce the background emission received by the sensor. For example, background emission may include emission originating from outside the appliance and / or emission originating from the sensor but reflected by the main unit, and thus these emission do not carry any information about the accessory or another object outside the main unit. Reducing the background can in turn improve the signal-to-noise ratio of the sensor. This in turn can improve the accuracy and / or resolution with which the control module can make the above determination. For example, the distance resolution of a TOF sensor (i.e., the minimum distance at which the targets must be separated to be distinguishable individually) can be expressed as a function of the signal-to-noise ratio and the integration time. Therefore, increasing the signal-to-noise ratio can allow the distance resolution to be reduced and / or the integration time to be reduced. Reducing the distance resolution can allow, for example, protrusions of different accessories to become more similar to each other, which can, for example, help reduce manufacturing costs. Reducing the integration time can allow determination to be made faster. Alternatively or in addition, for a given determination accuracy, reducing the background can allow the radial size of the portion and / or the reflectivity of the portion to be reduced. Reducing the radial dimension of the portion and / or the reflectivity of the portion can, for example, help reduce manufacturing costs. In an example, the anti-reflective component can include an anti-reflective coating applied to the surface. In an example, the anti-reflective coating can include an absorbing material that absorbs the emission. In the case where the emission is electromagnetic radiation, the anti-reflective coating can include, for example, a layer of dielectric material configured to reduce the reflectivity of a given emission wavelength. In an example, the anti-reflective component can include a baffle or other structure that is applied to the surface and configured to reduce the extent to which the emission is reflected from the surface to the sensor. For example, the baffle structure can include a series of spaced-apart plates that protrude from the surface and extend in a direction perpendicular to the sensor axis, although other structures are also possible. Other components configured to reduce the extent to which the emission is reflected from the surface of the main unit can be used.

[0019] The control module is operable to additionally determine the proximity of an object relative to the appliance based on the data output by the sensor. This has the advantage that the sensor is used for at least two purposes: (i) determining which of a plurality of accessories is attached to the main unit (and possibly also the rotational position of the accessories), and (ii) determining the proximity of the object to the appliance. The control module is operable to simultaneously determine the attachment (and possibly also the rotational position of the attachment) and the proximity of the object based on the data output by the sensor. The object may be an object on which the appliance operates. For example, the object may be a user, a surface, a workpiece, etc.

[0020] The appliance may include an electrical component, and the control module may be operable to control the electrical component in response to the proximity determination. Thus, the control module is capable of controlling the electrical component based on the proximity of the object to the appliance. For example, if the object is too close to the appliance, the electrical component may be controlled (e.g., powered off) to prevent or reduce potential damage to the object and / or the appliance. In another example, if the object is too far from the appliance, the electrical component may be controlled (e.g., powered off) to reduce power consumption and / or noise. In some examples, the control module may control the power of the electrical component based on the proximity of the object. For example, the control module may turn the electrical component on and off based on the proximity of the object. In another example, when the object approaches the appliance, the control module may reduce the power of the electrical component, and when the object is withdrawn from the appliance, increase the power. As described above, the electrical component may include an electric motor or a heater, and the control module may be operable to control the speed of the electric motor or the temperature of the heater in response to the proximity determination. Then, by operating the electric motor at a certain speed and / or by operating the heater at a temperature depending on the proximity of the object, the performance of the appliance can be improved. For example, when an object approaches the appliance, the control module can reduce the speed of the electric motor and / or reduce the temperature of the heater. Conversely, when the object moves away from the appliance, the control module can increase the speed of the electric motor and / or increase the temperature of the heater. In this way, the appliance can achieve a similar performance level regardless of the distance of the object relative to the appliance.

[0021] The appliance may include an airflow generator for drawing an airflow through the appliance, and the control module may be operable to control the characteristics of the airflow in response to the proximity determination. As a result, the performance of the appliance may be improved by controlling the airflow based on the proximity of the object. For example, the appliance may be a hair appliance and the object may be the hair of a user. When the hair is relatively close to the appliance, a high flow rate may move the hair excessively, resulting in an unsatisfactory styling effect and / or a high temperature may overdry or damage the hair. Therefore, when the hair is close to the appliance, the control module may reduce the flow rate and / or temperature of the airflow to achieve a better styling effect. In another example, the appliance may be a vacuum cleaner and the object may be a surface to be cleaned. The control module may then control the flow rate of the airflow based on the proximity of the surface. For example, when the surface is relatively far away from the appliance, the control module may power off or turn off the airflow generator to reduce power consumption and / or noise.

[0022] The device may include a plurality of accessories. Furthermore, each accessory may include a path through which a projectile travels between the sensor and the object. This has the advantage that, when attached to the main unit, each accessory may be located between the sensor and the object. The path in each accessory then ensures that the projectile is not blocked by the accessory, so that the proximity of the object can be determined.

[0023] The emission may include electromagnetic radiation, and the path may include one or more optical windows. This provides a relatively cost-effective mechanism for ensuring that the emission travels freely between the sensor and the object through the accessory. The optical windows of one or more accessories may include holes in the accessory, which further reduces the cost of the accessory. However, depending on the appliance and / or accessory, providing holes in the accessory may impair performance. Therefore, the optical windows of one or more accessories may include transparent or translucent members. The optical windows may have optical properties that are different for different accessories. The emission reflected by the optical window can then be used to determine which accessory is attached to the main unit. For example, where the optical window includes a transparent or translucent member, the transparency of the member may be different for different accessories. In other examples, the reflection or refraction of the optical window may be different for different accessories.

[0024] The appliance may be a hair appliance and the object may be the user's hair. As described above, by determining the proximity of the head to the appliance, better drying and / or styling results may be achieved. For example, a warning or other indication may be generated to indicate to the user that their head is too close and / or too far from the appliance. In other examples, the control module may control the flow rate and / or temperature of the airflow based on the proximity of the head.

[0025] The sensor may be a time of flight sensor, the main unit may include an end face to which one of a plurality of accessories may be attached, and the shortest distance between the sensor and the end face may be at least 20 mm. This has the advantage that a path of reasonable length may be established between the time of flight sensor and each accessory. As a result, it may be more reliably determined which accessory is attached to the main unit.

[0026] The main unit may include a barrel having a central hole, one of a plurality of accessories may be attached to one end of the barrel, and the sensor may be located within the hole. This has the benefit that a direct, unobstructed path may be provided between the sensor and the accessory. Additionally, projectiles may be better confined within the appliance. Furthermore, for appliances that already have an existing hole, the sensor may be incorporated without increasing the overall size of the appliance.

[0027] At least one of the plurality of accessories can rotate relative to the main unit about a rotation axis when attached to the main unit, and the sensor can be located on the rotation axis. As a result, the control module is able to determine which of the plurality of accessories is attached to the main unit regardless of the rotational position of the accessory.

[0028] According to a second aspect of the invention, there is provided an apparatus comprising: a main unit to which at least one accessory is attachable in any of a plurality of rotational positions about an axis of the main unit; a sensor operable to transmit a projectile and receive a reflected projectile; and a control module operable to determine a rotational position of the at least one accessory relative to the main unit when the at least one accessory is attached to the main unit. In an example, the apparatus may include at least one accessory, the at least one accessory may be configured to reflect a projectile toward the sensor when the accessory is attached to the main unit, and the sensor may be operable to receive a projectile transmitted by the sensor and reflected by the accessory when the accessory is attached to the main unit. When the accessory is attached to the main unit, the at least one accessory may include a plurality of portions distributed about the axis, and each of the plurality of portions may reflect a projectile to the sensor differently. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0030] Figure 1 It is a three-dimensional picture of the appliance;

[0031] Figure 2 is a side sectional view through the center of the main unit of the appliance;

[0032] Figure 3 This is the rear view of the main unit;

[0033] Figure 4 is a schematic diagram of the electrical components of the main unit;

[0034] Figure 5 is a side cross-sectional view of a portion of the appliance with the accessory attached to the main unit;

[0035] Figure 6 is with Figure 5 the same view showing the sensing cone of the time-of-flight sensor;

[0036] Figure 7 is a schematic diagram showing a rear view of an accessory according to one example; and

[0037] Figure 8 is a diagram illustrating a rear view of an accessory according to another example. DETAILED DESCRIPTION

[0038] Figures 1 to 6 The appliance 10 of WO 2014 / 036859 comprises a main unit 20 and a plurality of accessories 50 , 60 , each of which is attachable to the main unit 20 . In this example, the appliance 10 is a hair care appliance, and the accessories 60 , 70 include a concentrator 60 and a diffuser 70 .

[0039] The main unit 20 includes a handle portion 30 and a barrel portion 40 .

[0040] The handle portion 30 is generally cylindrical and includes a housing 31 that accommodates an airflow generator 51. The housing includes an inlet 32 ​​and an outlet 33, through which airflow is sucked into the handle portion 30 by the airflow generator 51, and through which airflow is discharged into the barrel 40. The airflow generator 51 includes a fan driven by an electric motor.

[0041] The barrel portion 40 is also generally cylindrical, but is shorter in length and wider in diameter than the handle portion 30. The barrel portion 40 is attached to one end of the handle portion 30 and is oriented so that the longitudinal axes of the handle portion 30 and the barrel portion 40 are orthogonal. As a result, the main unit 20 is shaped like a mallet or a wooden hammer.

[0042] The barrel 40 includes a housing 41 that accommodates a heater 52 and a control module 55. The housing 41 includes an outer wall 44 and an inner wall 45, which are generally concentric and define a chamber in which the heater 52 and the control module 55 are accommodated. The housing 41 includes an inlet 42 through which airflow from the handle portion 30 enters the chamber and an outlet 43 at one end of the barrel 40 through which airflow is discharged. The heater 52 is located between the inlet 42 and the outlet 43 and heats the airflow when powered. The inner wall 45 defines a hole 47 extending through the center of the barrel 40.

[0043] The main unit 20 also includes a sensor 53 , in this example a time of flight (TOF) sensor 53 , and user controls 54 .

[0044] The TOF sensor 53 is located in the hole 47 of the barrel 40. In this example, the TOF sensor 53 is an integrated package or integrated system including a transmitter, a receiver and a processor. The transmitter emits a projectile, which is a photon of electromagnetic radiation in this example. The transmitter emits the projectile in discrete pulses or group pulses, and the frequency is usually in the MHz range. For example, the transmitter can emit group pulses at a frequency of about 43MHz, and each group can include at least 80,000 pulses. In other examples, the projectile may include an acoustic (e.g., ultrasonic) pulse. The receiver then receives the reflected projectile, which has been reflected and returned to the TOF sensor 53. The processor then determines the time difference between the emission and reception of the projectile, and thereby calculates the distance between the TOF sensor 53 and the target responsible for the reflected projectile. The processor then outputs the distance data to the control module 55.

[0045] As explained in more detail below, the TOF sensor 53 is used to sense which (if any) of the accessories 60, 70 is attached to the main unit 20. In addition, the TOF sensor 53 is used to sense the proximity of the user's head or other object to the appliance 10. In this example, the control module 55 analyzes the distance data output by the TOF sensor 53, and determines (i) which accessory (if any) is attached to the main unit 20, and (ii) the proximity of the user's head based on the analysis. In one example, the distance data can take the form of a histogram, such as distance versus photon number. In another example, the distance data can include the number of targets detected by the TOF sensor 53 in one or more ranges and / or the distance of the target in each range. In other examples, the TOF sensor 53 itself, rather than the control module 55, can analyze the distance data and output data indicating which accessory (if any) is attached to the main unit 20 and / or the proximity of the user's head. In each of these examples, the control module 55 still determines which (if any) of the accessories 60, 70 is attached to the main unit 20 and the proximity of the user's head based on the data received from the TOF sensor 53. The control module 55 then uses this determination to control the flow rate and / or temperature of the airflow, as described further below.

[0046] The user controller 54 is disposed on the handle portion 30 and the barrel portion 40, and includes a first button 56 or a slider to turn the device 10 on and off, a second button 57 to temporarily turn off the heater 52 so that the device 10 delivers cold air, a third button 58 to control the flow rate of the airflow, and a fourth button 59 to control the temperature of the airflow.

[0047] The control module 55 is responsible for controlling the airflow generator 51 and the heater 52 in response to inputs from the TOF sensor 53 and the user controller 54. For example, in response to inputs from the user controller 54, the control module 55 can turn the airflow generator 51 and / or the heater 52 on and off. In addition, the control module 55 can control the power or speed of the airflow generator 51 to change the flow rate of the airflow. For example, repeatedly pressing the third button 58 can cause the control module 55 to cycle through different flow rates (e.g., low, medium, and high). Similarly, the control module 55 can control the power of the heater 52 to change the temperature of the airflow. For example, repeatedly pressing the fourth button 59 can cause the control module 55 to cycle through different temperature settings (e.g., cold, warm, hot).

[0048] The control module 55 also controls the airflow generator 51 and / or the heater 52 in response to the data output by the TOF sensor 53. As a result, better drying and / or styling effects can be achieved. For example, different attachments can provide better drying or styling effects when different flow rates and / or temperatures are used. For example, the diffuser 70 may provide better results when the airflow has a lower flow rate. By adopting a lower flow rate, the hair is moved less by the airflow, so the curls can be better defined. In contrast, the concentrator 60 may provide better results when the airflow has a higher flow rate. In another example, if the user's head is too close to the appliance, a high flow rate may move the hair excessively, resulting in an unsatisfactory styling effect and / or a high temperature may over-dry or damage the hair. Therefore, by controlling the flow rate and / or temperature of the airflow based on the attached attachment (if any) and / or the proximity of the user's head, better styling effects can be achieved.

[0049] The control module may store a plurality of different flow and temperature settings, and the control module may select one of the plurality of settings based on which accessory is attached to the main unit. For example, the control module may store default flow and temperature settings for each accessory. Additionally or alternatively, the control module may store the flow and temperature settings that were selected by the user the last time a particular accessory was used.

[0050] Figure 5 and 6 An arrangement is shown in which one of the accessories (in this case the concentrator 60 ) is attached to the main unit 20 .

[0051] Each accessory 60, 70 is attached to one end of the barrel 40 of the main unit 20. When attached, each accessory 60, 70 is free to rotate relative to the main unit 20 about the central longitudinal axis 48 of the barrel 40. This has the advantage that the user can achieve the desired airflow direction and angle without having to hold or manipulate the appliance 10 at an uncomfortable angle. In this example, each accessory 60, 70 includes an annular magnet 61, and the barrel includes an iron ring 49, and the magnet 61 is attracted to the iron ring 49 to fix the accessory 60, 70 in place. However, other mechanisms for achieving rotatable attachment of the accessory 60, 70 to the main unit 20 are also possible.

[0052] Each of the accessories 60, 70 includes a protrusion 62 that protrudes into the hole 47 of the barrel 40 toward the TOF sensor 53. Projections emitted by the TOF sensor 53 are reflected by the protrusion 62 and returned to the TOF sensor 53. The protrusions 62 of the accessories 60, 70 are different, so that the projections reflected by the protrusions of each accessory are different, for example, have different characteristics. In this example, the size of the protrusions 62 is different. More specifically, the lengths of the protrusions 62 are different, so that when a particular accessory 60, 70 is attached to the main unit 20, the amount by which the protrusion 62 protrudes toward the TOF sensor 53 is different from the amount of protrusion of other accessories 60, 70. The distance between the TOF sensor 53 and the protrusion 62 is therefore different for different accessories 60, 70. This is then reflected in the data output by the TOF sensor 53, which the control module 55 uses to determine which (if any) of the accessories 60, 70 is attached to the main unit 20.

[0053] In this example, the protrusions 62 of the accessories 60, 70 differ in size, and more specifically in their length. In other examples, the protrusions 62 may differ in additional or alternative ways, such as shape, surface features, or any other feature that substantially changes the way that projectiles are reflected by the protrusions 62. For example, the protrusions of each accessory may include a translucent material, possibly covered with a reflective material, and the material transparency may differ for different accessories. Providing each accessory 60, 70 with a different protrusion 62 than the other accessories 60, 70 provides a relatively cost-effective solution for distinguishing different accessories 60, 70. However, the accessories 60, 70 may include alternative features that reflect projectiles from the TOF sensor 53 differently.

[0054] As described above, each accessory 60, 70 is free to rotate relative to the main unit 20 about the longitudinal axis 48 of the barrel 40. Then, the TOF sensor 53 is located on the longitudinal axis 48 (i.e., the rotation axis of the accessories 60, 70). As a result, the TOF sensor 53 receives the same reflected emission from the accessories 60, 70 regardless of the rotational position of the accessories 60, 70. Therefore, the TOF sensor 53 is able to sense which of the accessories 60, 70 is attached to the main unit 20 regardless of the rotational position of the accessories 60, 70.

[0055] The TOF sensor 53 is disposed at a position fairly far back in the hole 47 of the barrel 40. In this example, the distance between the TOF sensor 53 and one end of the barrel 40 (i.e., the end to which the accessories 60, 70 are attached) is about 45 mm. This has the advantage that a path of reasonable length is established between the TOF sensor 53 and the protrusion 62 of each accessory 60, 70. As a result, it is possible to more reliably determine which accessory 60, 70 is attached to the main unit 20. For this reason, the distance between the TOF sensor 53 and one end of the barrel 40 may be no less than 20 mm.

[0056] As described above, the TOF sensor 53 is also used to sense the proximity of a user's head or other object relative to the appliance 10. In the absence of any accessories 60, 70, the TOF sensor 53 has a clear path through the aperture 47 of the barrel 40. As a result, the TOF sensor 53 is able to sense emissions reflected by the user's head near the outlet 43 of the appliance 10.

[0057] Each of the accessories 60, 70 includes a path through which projectiles can travel between the TOF sensor 53 and the user's head. Therefore, when the accessories 60, 70 are attached to the main unit 20, the TOF sensor 53 continues to have a path or line of sight to the user's head. In this particular example, the TOF sensor 53 emits photons (e.g., visible light or infrared light), and each accessory 60, 70 includes an optical path through the accessory 60, 70. In this example, the optical path is linear and includes one or more optical windows 63, 64 in the accessory 60, 70. In other examples, the path through the accessory 60, 70 can be non-linear and can include one or more optical elements (e.g., mirrors and / or lenses) for changing the direction of the projectile path. Each optical window 63, 64 can include an aperture or a transparent member. In some examples, one or both of the optical windows 63, 64 can include a translucent member, and the transparency of the member can be different for different accessories 60, 70. Projectiles reflected by the translucent member can be used to determine which of the accessories 60, 70 is attached to the main unit 20.

[0058] The TOF sensor 53 is thus able to simultaneously sense (i) which accessory 60, 70 (if any) is attached to the main unit, and (ii) the proximity of the user's head. It is conceivable that the TOF sensor 53 can be used to sense exactly one of these. In particular, the TOF sensor 53 can be used to sense only which accessory 60, 70 (if any) is attached to the main unit 20.

[0059] The main unit 20 may include more than one TOF sensor. For example, the main unit 20 may include a first TOF sensor for sensing which accessory 60, 70 (if any) is attached to the main unit 20, and a second TOF sensor for sensing the proximity of the user's head. In another example, the main unit 20 may include multiple TOF sensors, each sensing the proximity of an accessory and the user's head, in order to provide a more stable determination.

[0060] In addition to the TOF sensor 53, the main unit 20 can be conceived to include alternative means for determining which accessory 60, 70 is being used. For example, the main unit 20 may include electrical contacts or mechanical switches, and each accessory 60, 70 may contact different groups of contacts or actuate switches of different arrangements when attached. In another example, the main unit 20 may include one or more Hall effect sensors, and each accessory 60, 70 may include a unique arrangement of magnets. In each of these examples, the contacts, switches or sensors will need to be located at the end of the barrel 40 that intersects with the accessories 60, 70. However, it may be challenging to package additional components at the interface of the main unit 20. For example, there may not be enough space for components and / or required wiring, or the conditions of the path taken by the interface and / or wiring may be harsh (e.g., high temperature). For example, in this example, the space available at the end of the barrel 40 is relatively small, and the heater 52 is located between the end of the barrel 40 and the control module 55. By adopting the TOF sensor 53, the sensor 53 can be located away from the accessories 60, 70 and the end of the main unit 20 that interfaces with the accessories 60, 70. As a result, packaging of the TOF sensor 53 and cabling between the TOF sensor 53 and the control module 55 can be made easier. In addition, by adopting the TOF sensor 53, different accessories 60, 70 can be distinguished without providing additional components such as RFID tags, etc. for the accessories 60, 70. Therefore, different accessories 60, 70 can be remotely sensed in a relatively cost-effective manner.

[0061] In this example, each accessory 60, 70 may be attached to one end of the barrel 40 of the main unit 20, with the TOF sensor 53 located within the aperture 47 of the barrel 40. This has the benefit of providing a direct clear path between the TOF sensor 53 and each accessory 60, 70. In addition, stray emissions may be better confined within the appliance 10. Furthermore, for appliances that already have existing apertures, the TOF sensor 53 may be incorporated within the main unit without increasing the overall size.

[0062] In an example, one or more surfaces of the main unit 20 may include an anti-reflective component configured to reduce the extent to which emissions are reflected from one or more surfaces of the main unit 20 to the sensor 53. For example, the surface of the inner wall 45 defining the hole 47 in which the sensor 53 is located may have an anti-reflective component applied. The anti-reflective component may reduce the extent to which emissions emitted by the sensor 53 are reflected from one or more surfaces of the main unit 20, and may therefore reduce background emissions received by the sensor 53. For example, background emissions may include emissions that originate from the sensor 53 but are reflected by the main unit 20, and therefore do not carry any information about the accessory 60, 70 or another object external to the main unit 20. In some examples, the anti-reflective component may include an anti-reflective coating applied to one or more surfaces of the main unit 20. For example, where the emissions are electromagnetic radiation, the anti-reflective coating may include, for example, a layer of dielectric material configured to reduce the reflectivity of emissions of a given wavelength. In some examples, the anti-reflective component may include a baffle or other structure (not shown) applied to one or more surfaces of the main unit 20. The baffle structure (not shown) may, for example, include a series of plates extending from a surface of the main unit 20 and arranged to reduce the extent to which projectiles are reflected from the surface to the sensor 53. Other components configured to reduce the extent to which projectiles are reflected from the surface of the main unit 20 may be used.

[0063] In the example described above, the appliance 10 is a hair care appliance that emits an airflow for drying and styling hair. The control module 55 of the appliance 10 then controls the flow rate and / or temperature of the airflow based on the data output by the TOF sensor 53. In particular, the flow rate and / or temperature can be controlled based on which accessory 60, 70 (if any) is being used. In addition, the flow rate and / or temperature can be controlled based on the proximity of the user's head to the appliance 10.

[0064] The above principles can be used for other types of appliances with multiple different accessories. For example, the appliance can be a vacuum cleaner with a main unit, and one of the multiple different accessories can be attached to the main unit. The main unit can include an airflow generator that generates suction at each accessory. The accessories can include a first suction nozzle for the floor and a second suction nozzle for the interior decoration. When used for the floor, a higher suction force may be conducive to sucking in more dust. However, when used for interior decoration, a higher suction force may cause the interior decoration to be sucked in and block the suction nozzle. Therefore, a better effect can be achieved on the interior decoration with a lower suction force. Therefore, the main unit can include a TOF sensor and a control module, the TOF sensor senses which accessory is attached, and the control module controls the suction of the airflow generator based on the data output by the TOF sensor. In another example, the appliance can be an electric tool or the like including an electric motor for driving different accessories. The TOF sensor can sense which accessory is connected, and the control module can control the speed and / or torque of the electric motor based on the data output by the TOF sensor. Therefore, in a more general sense, the appliance 10 can be said to include a main unit 20, and one of the multiple accessories 60, 70 can be attached to the main unit 20. The appliance includes a TOF sensor 53 and a control module 55 operable to determine which of a plurality of accessories 60, 70 is attached to the main unit 20 based on data output by the TOF sensor 53. The control module may then control an electrical component (e.g., an electric motor, an airflow generator, or a heater) in response to the determination.

[0065] In the above example, the sensor 53 is a time-of-flight sensor 53. However, this need not be the case, and the sensor 53 may be any sensor (of which the time-of-flight sensor 53 is one example) operable to transmit emissions and receive reflected emissions.

[0066] Furthermore, in the above example, different accessories 60, 70 each include a protrusion 62 that protrudes a different amount toward the sensor 53. However, this need not be the case, and in examples, each accessory 60, 70 may include any portion (of which protrusion 62 is one example) configured to reflect radiation toward the sensor when the accessory 60, 70 is attached to the main unit 20, where the accessories 60, 70 are different such that the radiation reflected by the portion of each accessory 60, 70 is different.

[0067] In some examples, the accessories 60, 70 can differ according to the pattern or shape of the portion 62 protruding toward the sensor. For example, the portion can include multiple protrusions, such as an array of protrusions. Each protrusion can protrude a certain amount toward the sensor 53, and in doing so can encode the identity of the accessory 60, 70. For example, this can be similar to a barcode. The protrusion pattern can be different for different accessories. Then, the set or pattern of distances of the protrusions of a given portion from the sensor 53 is reflected in the data output by the sensor, and the control module 55 can then use the data to determine which accessory (if any) is attached to the main unit 20. For example, the control module 55 can map the set or pattern of distances to one of a plurality of patterns, each pattern being associated with a different accessory 60, 70, thereby determining which accessory 60, 70 is attached to the main unit 22.

[0068] In some examples, the portion may differ in size, shape, protrusion toward the sensor, pattern of protrusion of the portion toward the sensor, surface features, reflectivity, color, or any other feature that changes the way the portion reflects emissions in different attachments 60, 70.

[0069] For example, the sensor 53 may be operable to sense the intensity of reflected emissions (not necessarily operable to sense the time of flight of emissions). In this case, for example, the reflectivity of a portion of each accessory 60, 70 may be different for different accessories 60, 70. Thus, for different accessories 60, 70, the sensor 53 will sense different intensities of received emissions, which may be encoded in the data output by the sensor 53. Thus, the control module 55 may determine which accessory 60, 70 (if any) is attached to the main unit based on the data output by the sensor 53. In an example, the sensor 53 may be configured to emit emissions of a particular wavelength and only receive reflected emissions of that particular wavelength. This may help increase the sensitivity of the sensor 53.

[0070] As another example, the sensor 53 may be operable to sense a wavelength or range of wavelengths of a received emission (e.g., the color of a received emission). In this case, the wavelength or range of wavelengths of electromagnetic radiation reflected by a portion of each accessory 60, 70 (e.g., the color of the portion) may be different for different accessories. Thus, the control module 55 may determine which accessory 60, 70 (if any) is attached to the main unit based on the data output by the sensor 53.

[0071] Thus, it should be understood that in some examples, each accessory 60, 70 may include a portion 62 configured to reflect a projectile toward the sensor 53 when the accessory 60, 70 is attached to the main unit 20. The sensor 53 is operable to receive a projectile emitted by the sensor 53 and reflected by the portion 62 of the accessory 60, 70 when attached to the main unit 20. The accessories 60, 70 may be different such that the projectile reflected by the portion 62 of each accessory 60, 70 is different. For example, the sensor 53 (e.g., a TOF sensor 53) may be operable to sense the time of flight of a projectile, and the protrusion of the portion 62 toward the sensor 53 may be different for different accessories 60, 70. For example, the portion 62 of each of the plurality of accessories 60, 70 may include a protrusion 62 that protrudes toward the sensor 53 when the accessory 60, 70 is attached to the main unit 20, and the protrusion 62 may be of different sizes such that the protrusion 62 of each accessory 60, 70 protrudes toward the sensor 53 by a different amount when attached to the main unit. As another example, a sensor (eg, TOF sensor 53 or another sensor) may be operable to sense the intensity of reflected emissions, and the reflectivity of portion 62 may be different for different accessories 60 , 70 .

[0072] In some of the examples described above, the control module 55 uses data output by the TOF sensor 53 to determine the proximity of the accessories 60, 70 and the object (e.g., the user's head) attached to the main unit 20 relative to the appliance. In some examples, the control module 55 can be configured to monitor two ranges of TOF distance from the sensor 53: a first range in which the portion 62 of the accessory 60, 70 can be located when attached to the main unit 52, and a second range in which the object can be located (e.g., not overlapping with the first range and at a greater distance than the first range). The control module 55 can monitor these two ranges separately to determine which accessory 60, 70 (if any) is attached to the main unit 20, and to determine the proximity of the object to the appliance.

[0073] However, in some examples, such as where sensor 53 is operable to sense the intensity of a reflected emission (and not necessarily operable to sense the time of flight of an emission), other methods may be used to determine the proximity of an accessory and an object.

[0074] For example, the sensor 53 may include two emitters. The first emitter may be configured to emit a projectile onto a portion 62 of the accessory 60, 70 when attached to the main unit 20. The second emitter may be configured to emit a projectile onto an object. For example, the second emitter may be configured to emit a projectile through the accessory 60, 70 when attached to the main unit 20, such as through the optical window 63. For example, briefly referring to Figure 6, the first transmitter can be configured to transmit according to a wider cone 602, while the second transmitter can be configured to transmit according to a narrower cone 604. The output data associated with the emissions from the first transmitter can be used to determine which accessory (if any) is attached to the main unit 20, and the output data associated with the second transmitter can be used to determine the proximity of the object to the appliance. For example, by configuring the first transmitter and the second transmitter to transmit in different time slots from each other, the emissions from the first transmitter and the second transmitter can be distinguished. By monitoring the data output by the sensor 53 in different time slots, the control module 55 is able to determine which accessory 60, 70 (if any) is attached to the main unit 20 and the proximity of the object to the appliance. In other examples, the sensor may include multiple receivers. When the accessory 60, 70 is attached to the main unit, the first receiver can be configured to receive emissions reflected from a portion 62 of the accessory 60, 70. The second receiver can be configured to receive emissions reflected from the object. For example, again briefly referring to Figure 6 , the first receiver can be configured to have a field of view according to a wider cone 602, while the second receiver can be configured to have a field of view according to a narrower cone 604. As another example, the first receiver can be positioned radially offset from the optical window 63 and the second receiver can be positioned in line with the optical window 63. In either case, the output data associated with the first receiver can be used to determine which accessory (if any) is attached to the main unit 20, and the output data associated with the second receiver can be used to determine the proximity of the object to the appliance. In other examples, the sensor can include two pairs of transmitters and receivers, the first pair being associated with sensing accessories and the second pair being associated with sensing objects. The first and second pairs can operate, for example, with different fields of view, different time slots and / or different wavelengths, thereby allowing output data associated with sensing accessories 60, 70 and output data associated with sensing objects to be distinguished in the data output by the sensor 53. Other configurations can be used.

[0075] In the above examples, the accessories 60, 70 can be attached to the main unit 20 in any of a plurality of rotational positions about the axis 48 of the main unit. Specifically, in the above examples, when attached, each accessory 60, 70 is free to rotate relative to the main unit 20 about the central longitudinal axis 48 of the barrel 40. In some examples, when the accessory 60, 70 is attached to the main unit 20, the control module 55 is operable to additionally determine the rotational position of the accessory 60, 70 relative to the main unit. That is, the control module 55 can be configured to determine one or more of the following based on the data output by the sensor 53: (i) which accessory 60, 70 (if any) is attached to the main unit 20, (ii) the rotational position of the accessory 60, 70 attached to the main unit 20, and (iii) the proximity of the object to the appliance.

[0076] refer to Figure 7 and 8 An example method of determining the rotational position of an accessory attached to the main unit 20 is described. Figure 7 and Figure 8 Two different example methods are shown respectively. Figure 7 and Figure 8 All show the slave unit ( Figure 7 and Figure 8 Schematic diagram of a portion of an example accessory 60', 60" viewed along the rotation axis 48 of the accessory 60', 60". In these examples, the portion includes a protrusion 62', 62" of the accessory 60', 60", and the protrusion 62', 62" has an optical window 63', 63". However, in other examples, the accessory 60', 60" does not necessarily need to include the protrusion 62', 62", and another one or more portions of the accessory 60', 60" may be used. In some examples, the accessory 60', 60" may have the optical window 63', 63" as described above with reference to FIG. Figures 1 to 6 One or more features of accessories 60, 70 are described.

[0077] exist Figure 7 and Figure 8 In the example of , the accessory 60', 60", and in particular the protrusion 62', 62" of the accessory 60', 60", includes a plurality of portions 772-778, 882, 884 distributed about the axis 48, and each of the plurality of portions 772-778, 882, 884 is configured to reflect emissions to the sensor differently. For example, on a given accessory 60', 60", the portions 772-778, 882, 884 may differ in size, shape, protrusion toward the sensor, pattern of protrusion of the portions toward the sensor, surface features, reflectivity, or any other feature that changes the manner in which the portions reflect emissions. Because the portions 772-778, 882, 884 distributed about the axis 48 reflect emissions differently, the sensor may receive reflected emissions differently depending on the rotational position of the accessory 60', 60" about the axis. Therefore, the control module 55 may determine the rotational position of the accessory based on data output by the sensor.

[0078] Now refer to Figure 7 In the example of the embodiment of the present invention, the attachment includes a plurality of sections 772-778 (four sections in this example) distributed around the axis 48. A sensor (not shown) is configured to emit a projectile toward a reference rotational position 770 about the axis 48. For example, in Figure 7 The reference rotational position can be at 12 o'clock or zero degrees in the sense of . The rotational position of the accessory 60' can be determined based on the emission reflected by the portion 722 at the reference rotational position 770. For example, the sensor transmits an emission to the reference rotational position 770 and receives an emission reflected by any portion of the accessory at the reference rotational position (at Figure 7 , portion 772 in the reference rotational position 770. Since different portions 772-778 reflect the emission differently, portion 772 located at reference rotational position 770 will be encoded in the reflected emission received by the sensor and thus encoded in the data output by the sensor. The control module 55 can then determine the rotational position of the accessory based on the output data.

[0079] In an example, a projectile may be emitted toward a reference rotational position 770, but not toward other rotational positions. This may be provided, for example, by configuring the sensor to emit projectiles at the reference rotational position 700, and / or by applying a mask (not shown) between the sensor and the accessory 60', so that projectiles from the sensor are transmitted to the reference rotational position 770, but not to other rotational positions. In some examples, the sensor may emit projectiles toward the reference rotational position 770 and through the optical window 48. This may allow one or more of the following to be determined: (i) which accessory 60' (if any) is attached to the main unit 20; (ii) the rotational position of the accessory 60'; and (iii) the proximity of the object to the appliance. As an illustrative example, the sensor may include a single TOF sensor 53. The attachment 60' attached to the main unit 20 may be determined based on the protrusion 62' (e.g., portions 772-778) being within a certain distance range from the sensor. The rotational position of the accessory 60' may be determined based on the portion 772 located at the reference position 770 being a certain distance (e.g., within a certain range) from the sensor. The proximity of an object may be determined based on receiving a reflected emission that has traveled a certain threshold distance (eg, greater than the distance from the sensor to the far end of the accessory and back). Other configurations are also possible.

[0080] Now refer to Figure 8 In the example of, the accessory 62" includes a plurality of portions 882, 884 (two portions in this example) distributed about the axis 48. Specifically, in this example, the first portion 882 is configured to reflect emissions toward the sensor, and the second portion 884, which includes a surface of the protrusion 62" other than the first portion 882, is configured to reflect emissions differently than the first portion. For example, the second portion 884 can be configured not to reflect emissions toward the sensor at all, or to reflect emissions to a lesser extent than the first portion 882. In this example, the sensor generally transmits emissions toward the protrusion 62" (not necessarily only at a specific reference rotational position). In this example, the sensor includes a two-dimensional array 880 of receivers 886-892 (a 2×2 array in this example) that are operable to receive emissions emitted by the sensor and reflected by the first portion 882 of the accessory 60" when attached to the main unit 20. The receivers 886-892 are distributed about the rotational axis 48 and are arranged in a plane perpendicular to the axis 48. In Figure 8 , receivers 886-892 are shown in phantom to indicate that they are retracted from protrusion 62", such as sensor 53 in other examples described herein.

[0081] The two-dimensional array 880 of receivers 886 - 892 may allow determination of the position of the first portion 882 of the accessory 60 ″ in a plane perpendicular to the axis of rotation 48 , and thus determination of the rotational position of the accessory 60 ″ relative to the main unit 20 about the axis 48 . For example, when the accessory 60″ and therefore the first portion 882 are in different rotational positions, different receivers in the two-dimensional array 880 of receivers 886-892 can receive emissions reflected by the first portion 882 differently. For example, where the first portion 882 has a different reflectivity than the second portion 884, different receivers can receive reflected emissions of different intensities depending on the rotational position of the first portion 882. For example, the receiver 892 closest to the first portion 882 can receive the most reflected emissions from the first portion 882. As another example, where the first portion 882 protrudes toward the sensor by a different amount than the second portion 884, different receivers can receive reflected emissions with different flight times depending on the rotational position of the first portion 882. For example, the receiver 892 closest to the first portion 882 can receive emissions reflected from the first portion having the shortest flight time. In this case, the control module can determine that the rotational position of the accessory 60″ is the position where the first portion 882 is closest to the receiver 892. In either case, reflected emissions received differently at different receivers 886-892 can encode the rotational position of the first portion 882 about the axis 48, and the control module can determine the rotational position of the accessory 60" accordingly based on the data output by the sensors.

[0082] While specific examples and embodiments have been described thus far, it should be understood that these are illustrative only and that various modifications may be made without departing from the scope of the invention as defined by the claims.

Claims

1. An apparatus comprising: a main unit to which one of a plurality of accessories is attachable; a sensor operable to transmit a projection and receive a reflected projection; as well as A control module is operable to determine which of a plurality of accessories to attach to the main unit based on data output by the sensor.

2. The apparatus according to claim 1, wherein: The appliance includes an electrical component, and the control module is operable to control the electrical component in response to the determination.

3. The apparatus according to claim 2, wherein: The electrical component is an electric motor or a heater, and the control module is operable to control a speed of the electric motor or a temperature of the heater in response to the determination.

4. An apparatus as claimed in any one of the preceding claims, wherein: The appliance is a hair appliance comprising a plurality of flow and heat settings, and the control module is operable to select one of the settings based on the determination.

5. An apparatus as claimed in any one of the preceding claims, wherein: The apparatus includes the plurality of accessories, each accessory including a portion configured to reflect a radiation toward a sensor when the accessory is attached to the main unit, the sensor being operable to receive radiation emitted by the sensor and reflected by the portion of the accessory when the accessory is attached to the main unit, and the accessories being different such that the radiation reflected by the portion of each accessory is different.

6. The apparatus according to claim 5, wherein: The sensor is operable to sense a time of flight of the projectile, and the portion of the projection toward the sensor is different for different accessories.

7. The apparatus of claim 6, wherein: The portion of each of the plurality of accessories includes a protrusion that protrudes toward the sensor when the accessory is attached to the main unit, and the protrusions have different sizes so that the protrusion of each accessory protrudes toward the sensor by a different amount when the accessory is attached to the main unit.

8. The apparatus according to any one of claims 5 to 7, wherein: The sensor is operable to sense the intensity of the reflected emission, and the reflectivity of the portion is different for different accessories.

9. The apparatus of claim 8, wherein: The portion of each attachment comprises a translucent material, the transparency of the translucent material being different for different attachments.

10. An apparatus as claimed in any preceding claim, wherein: At least one accessory is attachable to the main unit in any one of a plurality of rotational positions about an axis of the main unit, and when the at least one accessory is attached to the main unit, the control module is operable to additionally determine the rotational position of the at least one accessory relative to the main unit.

11. The apparatus of claim 10, wherein: The appliance includes an electrical component, and the control module is operable to control the electrical component in response to the rotational position determination.

12. The apparatus according to claim 10 or 11, wherein: The apparatus includes at least one accessory configured to reflect emissions toward the sensor when the accessory is attached to the main unit, the sensor being operable to receive emissions emitted by the sensor and reflected by the accessory when the accessory is attached to the main unit, at least one accessory including a plurality of portions distributed about the axis when the accessory is attached to the main unit, and each of the plurality of portions reflecting emissions to the sensor differently.

13. The apparatus of claim 12, wherein: The sensor is configured to emit a missile toward a reference rotational position about the axis, and the rotational position of the at least one accessory is determined based on the missile reflected by one or more of the portions at the reference rotational position.

14. The apparatus according to claim 12 or 13, wherein: The sensor includes a two-dimensional array detector operable to receive emissions emitted by the sensor and reflected by one or more of the portions of the accessory when the accessory is attached to the main unit.

15. An apparatus as claimed in any preceding claim, wherein: The surface of the main unit includes an anti-reflection component configured to reduce the extent to which the emission is reflected from the surface of the main unit.

16. An apparatus as claimed in any preceding claim, wherein: The control module is operable to additionally determine a proximity of an object relative to the appliance based on data output by the sensor.

17. The apparatus of claim 16, wherein: The appliance includes an electrical component, and the control module is operable to control the electrical component in response to the proximity determination.

18. The apparatus according to any one of claims 16 to 17, wherein The apparatus includes the plurality of accessories, and each accessory includes a path through which the projectile travels between the sensor and the object.

19. The apparatus of claim 18, wherein: The path includes an optical window.

20. The apparatus of claim 19, wherein: The optical window has different optical properties for different accessories.

21. An apparatus as claimed in any one of claims 16 to 20, wherein The appliance is a hair appliance and the object is a user's head.

22. An apparatus as claimed in any preceding claim, wherein: The sensor comprises a time-of-flight sensor, the main unit comprises an end surface to which the one of the plurality of accessories is attachable, and a distance between the time-of-flight sensor and the end surface is at least 20 mm.

23. An apparatus as claimed in any preceding claim, wherein: The main unit includes a barrel having a central aperture, the one of a plurality of accessories being attachable to an end of the barrel, and the sensor being located within the aperture.

24. An apparatus as claimed in any preceding claim, wherein: At least one of the plurality of accessories is rotatable relative to the main unit about a rotation axis when attached to the main unit, and the sensor is located on the rotation axis.

25. An apparatus as claimed in any preceding claim, wherein: The appliance is a hair appliance.

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