Appliance

Abstract

An appliance includes a main unit to which one of a plurality of accessories is attachable, a capacitive sensor, 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 capacitive sensor.

Description

Technical Field

[0001] The present invention relates to an appliance, such as a hair care appliance. Background Art

[0002] Hair care appliances are typically used to treat or style hair, and some hair care appliances can use an air flow and / or heat to treat or style hair. Hair care appliances can be used to treat or style hair in a variety of different ways, and some hair care appliances include different attachments to provide different treatment or styling functions. Summary of the Invention

[0003] According to a first aspect of the present invention, there is provided an appliance comprising: a main unit to which one of a plurality of attachments is attachable; a capacitance sensor; and a control module operable to determine which one of the plurality of attachments is attached to the main unit based on data output by the capacitance sensor.

[0004] By employing a capacitance sensor, the control module can be capable of determining which one of the plurality of attachments is attached to the main unit without the need for any mechanical switches, or optical paths that may require precise alignment and / or movable parts that may be prone to failure. Furthermore, when compared with an arrangement that uses an optical sensing method to determine which attachment is attached to the main unit, using a capacitance sensor to determine which one of the plurality of attachments is attached to the main unit can provide greater flexibility in the selection of other sensing mechanisms for detecting other characteristics, such as the properties of an object external to the appliance. In particular, in some cases, using an optical sensing method to determine which attachment is attached to the main unit may preclude the use of another optical sensing method to determine the properties of an object external to the appliance, for example due to optical interference between the two sensing methods. Using a capacitance sensor to determine which attachment is attached to the main unit may not be subject to such interference and can enable an optical sensing method to be used to determine the properties of an object external to the appliance.

[0005] The appliance can be a hair care appliance.

[0006] The appliance can include electrical components, and the control module is operable to control the electrical components in response to the determination. The control module can thus control the electrical components differently for different attachments. The advantage of doing so is that the operation of the appliance can be automatically controlled according to the attachment being used. The control module is operable to control the input power of the electrical components in response to the determination.

[0007] The electrical component can be an electric motor or a heater, and the control module is operable to control the speed of the electric motor or the temperature of the heater in response to a determination. Based on the accessory being used, the performance of the appliance can be improved by operating the electric motor at different speeds and / or by operating the heater at different temperatures. For example, the appliance can be a hair care appliance, the electric motor can be used to generate an air flow, and the heater can be used to heat the air flow. Different accessories can then provide better drying or styling results at different flow rates and / or different heating settings.

[0008] The appliance can include an air flow generator for drawing an air flow through the appliance, and the control module is operable to control the characteristics of the air flow in response to a determination. Different accessories can provide better results for different air flows. For example, the appliance can be a hair care appliance, and the accessories can include a diffuser and a concentrator. The diffuser can provide better results when the air flow has a lower flow rate. This is because the air flow moves the hair less, so the curls are better defined. In contrast, the concentrator can provide better results when the air flow has a higher flow rate. For example, by employing a higher flow rate, drying and / or styling of the hair can be achieved more quickly.

[0009] The control module is operable to control one or more of the flow rate and temperature of the air flow. As described above, different accessories can provide better results for different flow rates. Additionally or alternatively, different accessories can provide better results for different temperatures. For example, the appliance can be a hair care appliance, and at least one accessory can provide better styling results at a lower heat setting, and at least one accessory can provide better styling results at a higher heat setting. By controlling the flow rate and / or temperature of the air flow in response to the accessory being used, better overall results can be achieved.

[0010] The appliance can be a hair care appliance including a plurality of flow rate and heat settings, and the control module is operable to select one of the settings based on the determination. As described above, different accessories can provide better results for different flow rates and / or heat settings. Therefore, by selecting one of the plurality of settings based on the accessory being used, better drying and / or styling results can be achieved.

[0011] The appliance can include a plurality of accessories, and each of the plurality of accessories can be configured to cause a different capacitance response of a capacitance sensor, e.g., the capacitance sensor measures different capacitance responses. This can enable determination of which accessory is attached to the main unit based on the data output by the capacitance sensor in the manner described above.

[0012] The main unit may include a first electrode, and each of the plurality of accessories may include a corresponding second electrode, each second electrode being different from every other second electrode. By providing different second electrodes for each accessory, each accessory may provide a different capacitance response to the capacitance sensor, such as when the second electrode covers the first electrode, enabling the control module to distinguish between different accessories when they are attached to the main unit.

[0013] Each second electrode may include a cross-sectional area different from that of every other second electrode. This may provide a relatively simple way to provide different capacitance responses to the capacitance sensor between different accessories.

[0014] A first accessory among the plurality of accessories may include a first number of second electrodes, and a second accessory among the plurality of accessories may include a second number of second electrodes different from the first number of second electrodes. This may provide a relatively simple way to provide different capacitance responses to the capacitance sensor between different accessories.

[0015] Data output by the capacitance sensor may indicate the capacitance value measured when a corresponding one of the plurality of accessories is attached to the main unit. Providing data indicating the measured capacitance value may provide a relatively direct numerical value for comparison to determine which accessory is attached to the main unit.

[0016] The first electrode may include a plurality of first electrodes, and the data output by the capacitance sensor may indicate the number of the plurality of first electrodes that overlap with the second electrode thereof when a corresponding one of the plurality of accessories is attached to the main unit. This may provide a relatively direct metric by which to compare and determine which one of the plurality of accessories is attached to the main unit. For example, for a given first electrode array, second electrodes of different sizes may overlap with different numbers of first electrodes, thereby providing different capacitance responses.

[0017] The capacitance sensor may include a multi-channel capacitance sensor, each channel corresponding to a different one of the plurality of first electrodes. In this way, different numbers of channels may provide variations in capacitance response according to the degree of overlap of the second electrode with the plurality of first electrodes, and counting the number of channels with capacitance response variations may provide a simple way to compare and determine which one of the plurality of accessories is attached to the main unit.

[0018] The size of each second electrode can be designed such that the second electrode overlaps with a discrete subset (e.g., a non-empty subset) of the plurality of first electrodes. The size of at least some of the second electrodes can be designed such that, depending on the rotational orientation of the corresponding attachment to the main unit, the second electrode overlaps with different subsets of the plurality of first electrodes. The size of at least some of the second electrodes can be designed such that, depending on the rotational orientation of the corresponding attachment to the main unit, the second electrode overlaps with different cardinality subsets of the plurality of first electrodes. For example, each second electrode can be positioned relative to the first electrodes such that the second electrode overlaps with a first cardinality subset of the plurality of first electrodes or a second cardinality subset of the plurality of first electrodes.

[0019] The second electrodes can include a plurality of second electrodes. The combined use of the plurality of second electrodes and the plurality of first electrodes can provide a greater combination of possible overlapping patterns of the electrodes, which can allow for differentiation between a greater number of attachments compared to an embodiment where a single second electrode is used with the plurality of first electrodes.

[0020] The plurality of first electrodes can be arranged in a substantially circular array, and each second electrode can be arcuate.

[0021] The plurality of first electrodes and each second electrode can be configured such that the data output by the capacitance sensor depends on the rotational orientation of the attachment to the main unit. This can enable determination of the rotational orientation of the attachment to the main unit.

[0022] The plurality of first electrodes and each second electrode can be configured such that the data output by the capacitance sensor is constant for a given attachment, regardless of the rotational orientation of the attachment to the main unit. For example, for a given attachment, the capacitance response measured by the capacitance sensor can be constant, regardless of the rotational orientation of the attachment to the main unit. This can ensure correct determination of which attachment is attached to the main unit, regardless of the rotational orientation of the attachment to the main unit.

[0023] The main unit can include an interface portion configured to dock with the main unit of a hair care appliance, the interface portion including an electrode layer, wherein the electrode layer is exposed at the interface portion.

[0024] The main unit can include a first electrode and a first dielectric portion covering the first electrode, and each of the plurality of attachments can include a corresponding second electrode and a corresponding second dielectric portion covering the second electrode. Providing such dielectric portions can inhibit the user from contacting the electrodes during use.

[0025] Each second dielectric portion can be different from each other second dielectric portion. This can provide a relatively simple mechanism by which different attachments can provide different capacitance responses, for example while keeping the body the same between attachments.

[0026] Each second dielectric portion may include a thickness different from each other second dielectric portion. This may provide a relatively simple mechanism for providing different capacitance responses between different attachments.

[0027] The first and second dielectric portions may be formed of the same dielectric material.

[0028] The first dielectric portion may be unevenly distributed on the first electrode.

[0029] Each of the plurality of attachments may include a respective second electrode and a respective second dielectric portion covering the second electrode, and each second dielectric portion may be different from each other second dielectric portion.

[0030] The capacitive sensor may detect without signal interference, such as radio frequency or magnetic induction with other electronic components in the appliance. It only detects the capacitance value between two or more electrodes arranged with dielectric layers.

[0031] The main unit may include a drive electrode and a receiver electrode, and each of the plurality of attachments may include a respective second electrode, each second electrode being different from each other second electrode. In this way, each second electrode may affect the magnetic field present between the drive electrode and the receiver electrode, and since each second electrode is different, the second electrodes and thus the attachments may provide different capacitance responses when attached to the body. This arrangement may provide greater stability than, for example, an arrangement where physically opposing electrodes are present on the main unit and the attachment, where spikes in capacitance measurements may occur due to the speed of attachment of the attachment to the main unit.

[0032] Each second electrode may include a cross-sectional area and / or thickness different from each other second electrode.

[0033] The appliance may include a transmitter configured to emit light radiation, a light sensor configured to receive reflected light radiation from an object external to the appliance, and another control module configured to determine an attribute of the object based on another data output by the optical sensor. This may enable the appliance to determine which attachment is attached to the main unit, as well as the attributes of an object external to the appliance. For example, the attributes of the object may include any one of the following: the presence or absence of the object, the type of the object, the distance of the object from the main unit, the distance of the object from the attachment, the temperature of the object, and the water content of the object. The transmitter and the optical sensor may include a time-of-flight sensor. The another control module and this control module may be the same control module.

[0034] The appliance may include electrical components, and the another control module may be operable to control the electrical components in response to the determination of the object attribute. Thus, the another control module is capable of differently controlling the electrical components for different attributes of the external object.

[0035] The electrical component can be an electric motor or a heater, and another control module is operable to control the speed of the electric motor or the temperature of the heater in response to the determination of the object property.

[0036] The appliance can include an air flow generator for drawing an air flow through the appliance, and another control module is operable to control the characteristics of the air flow in response to the determination of the object property.

[0037] Another control module is operable to control one or more of the flow rate and temperature of the air flow.

[0038] The appliance can be a hair care appliance including a plurality of flow rate and heat settings, and another control module is operable to select one of the settings based on the determination of the object property.

[0039] At least some of the plurality of attachments can include a portion of an optically transparent material. The emitter can be configured to emit light radiation to a corresponding portion of the optically transparent material of one of the plurality of attachments when the attachment is attached to the main unit, and the optical sensor can be configured to receive the reflected light radiation from an object outside the appliance through the corresponding portion of the optically transparent material.

[0040] The main unit can include a cylindrical portion having a central hole. A plurality of attachments can be attached to one end of the cylindrical portion, and at least one of the emitter and the optical sensor is located within the hole.

[0041] This can provide a direct and unobstructed path between the emitter and the attachment, and / or between the attachment and the optical sensor. Additionally, the emission can be better confined within the appliance. Further, for an appliance that already has an existing hole, the emitter and / or optical sensor can be incorporated without increasing the overall size of the appliance.

[0042] The first electrode can be substantially annular around one end of the hole. A plurality of first electrodes can be arranged in a substantially annular array around one end of the hole.

[0043] According to a second aspect of the present invention, there is provided an attachment for a hair care appliance, the attachment including an interface portion configured to dock with the main unit of the hair care appliance, an electrode layer located at the interface portion, and a dielectric layer covering the electrode layer such that the dielectric layer is exposed at the interface portion.

[0044] Where appropriate, the optional features of the aspects of the present invention can be equivalently applied to other aspects of the present invention. Description of the Drawings

[0045] Figure 1 is a schematic diagram of a first embodiment of a hair care appliance;

[0046] Figure 2 is Figure 1Schematic cross-sectional view of the main unit of a hair care appliance;

[0047] Figure 3 is Figure 2 Schematic rear view of the main unit of

[0048] Figure 4 is Figure 1 Schematic view of the electrode array of a hair care appliance of

[0049] Figure 5 is Figure 1 Schematic view of an accessory of a hair care appliance of

[0050] Figure 6 is Figure 5 Positioning of the electrodes of the accessory of Figure 4 relative to the electrode array of

[0051] Figure 7 is when the accessory is attached to the main unit Figure 1 Schematic view of a hair care appliance of

[0052] Figure 8 Schematic view of a second embodiment of a hair care appliance;

[0053] Figure 9 is Figure 8 Schematic view of the electrode positioning of a hair care appliance of

[0054] Figure 10 is Figure 9 Schematic view of an alternative embodiment of an accessory of a hair care appliance of

[0055] Figure 11 is a schematic view of the capacitance reading of the accessory; and

[0056] Figure 12 Schematic view of a third embodiment of a hair care appliance. DETAILED DESCRIPTION

[0057] In Figures 1-3 a first embodiment of an appliance 10 in the form of a hair care appliance is schematically shown. The appliance 10 includes a main unit 12 and a plurality of accessories 14, 16, each of which can be attached to the main unit 12. Here, the accessories 14, 16 include a concentrator 14 and a diffuser 16, although it will be understood that other types of accessories can also be contemplated.

[0058] The main unit 12 is in Figure 2 and 3is shown schematically separately in the figure and includes a handle portion 18, a head portion 20, an air flow generator 22, a heater 24, a user controller 26, a control module 28, a plurality of first electrodes 30, a first dielectric layer 32, a capacitance sensor 34, and a time-of-flight sensor 36. It should be understood that in some examples, the capacitance sensor 34 may be integrated with the control module 28, for example, as a single unit.

[0059] The handle portion 18 is generally in the form of a cylinder and is hollow, and houses the air flow generator 22. The handle portion 18 has a plurality of air inlets 38 in the form of perforations at a first end 40 of the handle portion 18.

[0060] The head portion 20 is generally cylindrical and hollow, and is provided at a second end 42 of the handle portion 18. The central axis of the head portion 20 is orthogonal to the central axis of the handle portion 18, such that the main unit 12 is generally T-shaped. The head portion 20 houses the heater 24. The head portion 20 includes a hole 44 and an air outlet 46, and air is entrained through the hole 44. The air outlet 46 is generally annular around the perimeter of the hole 44. The head portion 20 further includes an annular magnet (not shown) for releasably connecting the handle unit 12 to the attachments 14, 16. The annular magnet extends annularly around the air outlet 46.

[0061] The user controller 26 is provided on the handle portion 18 and the head portion 20, and includes a first button 48 or a slider to turn on and off the appliance 10, a second button 50 to temporarily turn off the heater 24 so that the appliance 10 delivers a cold air stream, a third button 52 to control the flow rate of the air stream, and a fourth button 54 to control the temperature of the air stream.

[0062] The control module 28 is responsible for controlling the air flow generator 22 and the heater 24 in response to inputs from the user controller 26. For example, in response to an input from the user controller 26, the control module 28 may turn on and off the air flow generator 22 and / or the heater 24. In addition, the control module 28 may control the power or speed of the air flow generator 22 in order to change the flow rate of the air stream. For example, repeatedly pressing the third button 52 may cause the control module 28 to cycle through different flow rates (e.g., low, medium, and high). Similarly, the control module 28 may control the power of the heater 24 in order to change the temperature of the air stream. For example, repeatedly pressing the fourth button 54 may cause the control module 28 to cycle through different temperature settings (e.g., cold, warm, hot).

[0063] The control module 28 also controls the air flow generator 22 and the heater 24 in response to inputs from the capacitance sensor 34 and the time-of-flight sensor 36, which will be discussed in more detail below.

[0064] The plurality of first electrodes 30 includes 12 electrodes evenly spaced in an annular array, as Figure 4is schematically shown. A plurality of first electrodes 30 are located within the head 20 such that the plurality of first electrodes 30 extend annularly around the air outlet 46. The plurality of first electrodes 30 each have a substantially similar cross-sectional area and are formed of a suitable conductive material such as copper. In other examples, magnetic materials for connecting the main unit 12 to the accessories 14, 16 may be located within the main unit and may also be used to define the plurality of first electrodes 30.

[0065] The first dielectric layer 32 is generally annular and covers the plurality of first electrodes 30 such that the plurality of first electrodes 30 are not exposed to the environment external to the head 20. An exemplary material for the first dielectric material 32 is a polyimide material.

[0066] The capacitance sensor 34 includes a twelve-channel capacitance sensor and is located within the handle portion 18 at the second end 42. The capacitance sensor 34 is electrically connected to the plurality of first electrodes 30 via a cable (not shown for clarity).

[0067] The time-of-flight (TOF) sensor 36 is located within the bore 44 along the central axis of the bore 44 such that the TOF sensor 36 is located radially inward of the sensor assembly 56. The TOF sensor 36 is an integrated package or an all-in-one system that includes a transmitter, a receiver, and a processor. The transmitter emits radiation, which in this example is photons of electromagnetic radiation. The receiver then receives the reflected emission that has been reflected and returned to the TOF sensor 36. The processor then determines the time difference between the emission and the received emission and thereby calculates the distance between the TOF sensor 36 and the target responsible for reflecting the emission. The processor then outputs the distance data to the control module 28.

[0068] Each of the concentrator and diffuser accessories 14, 16 is formed of an optically transparent material and further includes a respective second electrode 56, 58 and a respective second dielectric material 60, 62, as Figure 5 and 6 is schematically shown. Each second electrode 56, 58 is arcuate and is located on the respective concentrator and diffuser accessories 14, 16 such that when the accessories 14, 16 are attached to the head 20 of the main unit 12, they cover at least some of the plurality of first electrodes 30, regardless of the rotational orientation of the accessories 14, 16 relative to the head 20. As Figure 6 shown, the arcuate extent of each second electrode 56, 58 is different such that each second electrode 56, 58 has a different cross-sectional area. The second electrodes 56, 58 are formed of a suitable conductive material such as copper. The second dielectric materials 60, 62 cover the respective second electrodes 56, 58 such that the second electrodes 56, 58 are not exposed to the environment external to the respective accessories 14, 16. Exemplary materials for the second dielectric materials 60, 62 are polyimide materials or high-dielectric ceramic materials.

[0069] In use, one of the accessories 14, 16 is attached to the head 20 of the main unit 12, and this configuration is schematically shown in Figure 7 with the concentrator accessory 14. The control module 28 can determine which of the accessories 14, 16 is attached to the main unit 12 and can control the implement 10 accordingly. In particular, the capacitance sensors 34, the plurality of first electrodes 30, and the second electrodes 56, 58 can be used to determine which of the accessories 14, 16 is attached to the main unit 12.

[0070] Since each of the second electrodes 56, 58 has a different arc range, when the corresponding accessories 14, 16 are attached to the main unit, each of the second electrodes 56, 58 overlaps with a different number of the plurality of first electrodes 30, e.g., the second electrodes 56, 58 overlap with subsets of the plurality of first electrodes having different cardinalities. This is schematically shown in Figure 6 where the second electrode 56 of the concentrator accessory 14 overlaps with nine of the plurality of first electrodes 30 and the second electrode 58 of the diffuser accessory 16 overlaps with two of the plurality of first electrodes 30. Thus, depending on which of the accessories 14, 16 is attached to the main unit 12, the capacitance sensors 34 have variations in capacitance readings on different numbers of its 12 channels, and then the control module 28 can determine which of the accessories 14, 16 is attached to the main unit 12 based on the number of channels on which the capacitance sensors 34 have readings. The control module 28 then uses this determination to control the flow rate and / or temperature of the air stream, as further described below.

[0071] The TOF sensor 36 is used to sense the proximity of the user's head or other object to the implement 10. In this example, the control module 28 analyzes the distance data output by the TOF sensor 36 and determines the proximity of the user's head based on this analysis. In other examples, the TOF sensor 36 itself, rather than the control module 28, can analyze the distance data and output data representing the proximity of the user's head. In each of these examples, the control module 55 still determines the proximity of the user's head based on the data received from the TOF sensor 36. The control module 28 then uses this determination to control the flow rate and / or temperature of the air stream.

[0072] As described above, the control module 28 controls the air flow generator 22 and the heater 24 in response to inputs from the capacitance sensor 34 and the time-of-flight sensor 36. As a result, better drying and / or styling results can be achieved. For example, different attachments can provide better drying or styling results when using different flow rates and / or temperatures. For example, when the air flow has a lower flow rate, the diffuser attachment 16 may provide better results. By using a lower flow rate, the hair is moved less by the air flow, so the curls can be better defined. In contrast, when the air flow has a higher flow rate, the concentrator attachment 14 may provide better results. In another example, if the user's head is too close to the appliance, the high flow rate may move the hair excessively, resulting in unsatisfactory styling results and / or the high temperature may over-dry the hair or damage the hair. Therefore, better styling results can be achieved by controlling the flow rate and / or temperature of the air flow based on which attachment 14, 16 (if any) is attached and / or the proximity of the user's head.

[0073] The control module 28 can store a plurality of different flow rate and temperature settings, and the control module 28 can select one of the plurality of settings based on which of the attachments 14, 16 is attached to the main unit. For example, the control module 28 can store the default flow rate and temperature settings for each of the attachments 14, 16. Additionally or alternatively, the control module 28 can store the flow rate and temperature settings selected by the user the last time a particular attachment 14, 16 was used.

[0074] In this way, appropriate flow rate and / or temperature settings can be determined for a particular attachment 14, 16 and / or a particular distance of the user's head relative to the appliance. The use of the capacitance sensor 34 can provide an attachment identification system that does not require any electrical contacts or mechanical switches, which may require precise alignment and / or movable parts that may be prone to failure.

[0075] Furthermore, when compared to an arrangement that uses an optical sensing method to determine which attachment 14, 16 is attached to the main unit 12, using the capacitance sensor 34 to determine which of the plurality of attachments 14, 16 is attached to the main unit 12 can provide greater flexibility in the selection of other sensing mechanisms for detecting other characteristics (e.g., the properties of an object outside the appliance 10). In particular, the use of the capacitance sensor 34 can facilitate the use of the TOF sensor 36 by minimizing the risk of interfering with the emission of the TOF sensor 36.

[0076] Given the spacing between the electrodes among the plurality of first electrodes 30 and the arcuate ranges of the second electrodes 56, 58, it can be appreciated that each of the second electrodes 56, 58 can overlap with a different number of the plurality of first electrodes 30, depending on the rotational orientation of the respective accessories 14, 16 relative to the main unit 12. For example, depending on the rotational orientation of the concentrator accessory 14 relative to the main unit 12, the second electrode 56 of the concentrator accessory 14 can overlap with eight or nine of the plurality of first electrodes 30. Similarly, depending on the rotational orientation of the concentrator accessory 14 relative to the main unit 12, the second electrode 58 of the diffuser accessory 16 can overlap with two or three of the plurality of first electrodes 30.

[0077] Taking this into account, the control module 28, for example, the number range of the plurality of first electrodes 30 provides a variation in the capacitance response associated with each accessory 14, 16. It should be understood that in view of the nature of the 12 channels and the corresponding 12 first electrodes 30, the capacitance sensor 34 is capable of detecting a greater number of accessories than just two, and in fact, when considering variations in rotational orientation, the capacitance sensor 34 can identify 6 different accessories using the 12 channels.

[0078] In Figure 8 a second embodiment of an appliance 200 in the form of a hair care appliance is schematically shown, where, for the sake of clarity, the same reference numerals are used.

[0079] The second embodiment of the appliance 200 differs from the first embodiment of the appliance 10 in the form of the first electrode 202 and the capacitance sensor 204 and thus the form of the main unit 205.

[0080] The first electrode 202 is a single annular electrode located within the head 20 such that the first electrode 202 extends annularly around the air outlet 46. The first electrode 202 has a fixed cross-sectional area and is formed of a suitable conductive material such as copper.

[0081] The capacitance sensor 204 includes a single-channel capacitance sensor and is located within the handle portion 18 at the second end 42. The capacitance sensor 204 is electrically connected to the first electrode 202 via a cable (not shown for the sake of clarity).

[0082] The accessories 14, 16 are the same as those of the first embodiment of the appliance 10 and are formed of an optically transparent material and further include the respective second electrodes 56, 58 and the respective second dielectric materials 60, 62.

[0083] In use, one of the accessories 14, 16 is attached to the head 20 of the main unit 205 in a manner similar to that described with respect to the first embodiment 10 of the above-mentioned appliance. The control module 28 can determine which of the accessories 14, 16 is attached to the main unit 205 and can control the appliance 10 accordingly. In particular, the capacitance sensors 204, the first electrode 202, and the second electrodes 56, 58 can be used to determine which of the accessories 14, 16 is attached to the main unit 205.

[0084] Since each of the second electrodes 56, 58 has a different arcuate extent, e.g., a different cross-sectional area, each of the second electrodes 56, 58 overlaps the first electrode 202 to a different extent when the corresponding accessory 14, 16 is attached to the main unit 205. This is schematically shown in Figure 9 where the second electrode 56 of the concentrator accessory 14 overlaps the first electrode 202 to a greater extent than the second electrode 58 of the diffuser accessory 16. Thus, due to the different cross-sectional areas of the second electrodes 56, 58 of the accessories 14, 16, the capacitance readings of the capacitance sensor 204 are different depending on which of the accessories 14, 16 is attached to the main unit 205. For example, with the distance between the first and second electrodes remaining unchanged, a relatively large cross-sectional area of the second electrode will result in a different capacitance reading compared to a relatively small cross-sectional area of the second electrode.

[0085] The control module 28 can then determine which of the accessories 14, 16 is attached to the main unit 205 based on the capacitance value measured by the capacitance sensor 204, e.g., by making a suitable comparison with a set of predetermined discrete capacitance values or ranges. As described above, the control module 28 then uses this determination to control the flow rate and / or temperature of the air flow.

[0086] It is also conceivable to vary the thickness of the second dielectric materials 60, 62 of the first accessory 14 and the second accessory 16 as an alternative or supplement to accessory identification using second electrodes of different cross-sectional areas. Figure 10 Exemplary accessories 250, 252 in the form of a concentrator 250 and a diffuser 252 accessory for use with the main unit 205 of the second embodiment of the appliance 200 are shown, where the dielectric thickness varies. Each accessory 250, 252 has an annular second electrode 254 and corresponding second dielectric layers 256, 258. The dielectric layers 256, 258 are formed of polyimide or any other type of high dielectric material such as plastic or ceramic and cover the corresponding annular second electrode 254. The second dielectric layer 256 of the concentrator accessory 250 has a first thickness T1, while the second dielectric layer 258 of the diffuser accessory 252 has a second thickness T2 greater than the first thickness T1.

[0087] In use, one of the accessories 250, 252 is attached to the head 20 of the main unit 205 in a manner similar to the second embodiment 200 of the appliance described above. The control module 28 can determine which of the accessories 250, 252 is attached to the main unit 205 and can accordingly control the appliance 10. In particular, the capacitance sensors 204, the first electrode 202, the second electrodes 254 and the respective second dielectric layers 256, 258 can be used to determine which of the accessories 14, 16 is attached to the main unit 12.

[0088] Since each of the second dielectric layers 256, 258 has a different thickness, the capacitance sensor 204 has a variation in capacitance readings that differs depending on which of the accessories 250, 252 is attached to the main unit 205. For example, a relatively thick dielectric layer with no change in cross-sectional area between the first and second electrodes will result in a different capacitance reading compared to a relatively thin dielectric layer.

[0089] The control module 28 can then determine which of the accessories 250, 252 is attached to the main unit 205 based on the capacitance value measured by the capacitance sensor 204, for example by making an appropriate comparison with a set of predetermined discrete capacitance values or ranges. As described above, the control module 28 then uses this determination to control the flow rate and / or temperature of the air flow. Figure 11 Capacitance readings for four A - D accessories with different dielectric material thicknesses are shown.

[0090] In Figure 12 a third embodiment of an appliance 300 in the form of a hair care appliance is schematically shown, where the same reference numerals are used for clarity.

[0091] The third embodiment of the appliance 300 differs from the second embodiment of the appliance 200 in that the drive electrode 302 and the receiver electrode 304 replace the first electrode 202. The drive electrode 302 and the receiver electrode 304 are spaced apart around the perimeter of the air outlet 46. In use, the drive electrode 302 is driven so as to generate an electromagnetic field or an electric field. When accessories such as a concentrator accessory 14 and a diffuser accessory 16 having different arc ranges of second electrodes 56, 58 are attached to the main unit 205, the second electrodes interfere with the electromagnetic field generated by the drive electrode. This interference has an effect on the capacitance response measured at the capacitance sensor 204, and the difference in the second electrodes 56, 58 means that each accessory 14, 16 provides a different capacitance response when attached to the main unit 205. This capacitance interaction can be referred to as mutual capacitance sensing.

[0092] The control module 28 can then determine which of the attachments 14, 16 is attached to the main unit 205 based on the capacitance value measured by the capacitance sensor 204, for example, by making a suitable comparison with a set of predetermined discrete capacitance values or ranges. The control module 28 then uses this determination to control the flow rate and / or temperature of the air flow, as further described above.

[0093] In the above examples, the appliances 10, 200, 300 are hair care appliances that emit an air flow to dry and style hair. The control module 28 of the appliances 10, 200, 300 then controls the flow rate and / or temperature of the air flow based on the data output by the capacitance sensor. In particular, the flow rate and / or temperature can be controlled according to the attachment (if any) being used. Additionally, the flow rate and / or temperature can be controlled according to the proximity of the user's head to the appliances 10, 200, 300 determined by the TOF sensor 36.

[0094] The above principle can be applied to other types of appliances having multiple different attachments. For example, the appliance can be a vacuum cleaner having a main unit, and one of a plurality of different attachments can be attached to the main unit. The main unit can include an air flow generator that generates suction at each attachment. The attachments can include a first nozzle for floors and a second nozzle for upholstery. When used on floors, a higher suction may be beneficial for sucking in more dust. However, when used on upholstery, a higher suction may cause the upholstery material to be sucked in and clog the nozzle. Therefore, better results can be achieved on upholstery with a lower suction. Thus, the main unit can include a capacitance sensor and a control module that senses which attachment is attached and controls the suction of the air flow generator based on the data output by the capacitance sensor. In another example, the appliance can be a power tool, etc., that includes an electric motor for driving different attachments. The capacitance sensor can sense which attachment is attached, and the control module can control the speed and / or torque of the electric motor based on the data output by the capacitance sensor. Thus, in a more general sense, it can be said that the appliance includes a main unit to which one of a plurality of attachments can be attached. The appliance includes a capacitance sensor and a control module that is operable to determine which of the plurality of attachments is attached to the main unit based on the data output by the capacitance sensor. The control module can then control an electrical component (such as an electric motor, an air flow generator, or a heater) in response to this determination.

[0095] While specific examples and embodiments have been described thus far, it should be understood that these are merely illustrative and that various modifications can be made without departing from the scope of the invention as defined by the claims.

Claims

1. An appliance, comprising: a main unit to which one of a plurality of accessories can be attached; a capacitance sensor; and a control module operable to determine, based on data output by the capacitance sensor, which one of the plurality of accessories is attached to the main unit.

2. The apparatus according to claim 1, wherein, The appliance includes electrical components, and the control module is operable to control the electrical components 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 the speed of the electric motor or the temperature of the heater in response to the determination.

4. The apparatus according to any one of the preceding claims, wherein, The appliance includes an air flow generator for drawing an air flow through the appliance, and the control module is operable to control the characteristics of the air flow in response to the determination.

5. The apparatus according to claim 4, wherein The control module is operable to control one or more of the flow rate and temperature of the air flow.

6. The apparatus according to any one of the preceding claims, wherein, The appliance is a hair care appliance including a plurality of flow and heat settings, and the control module is operable to select one of the settings based on the determination.

7. The apparatus according to any one of the preceding claims, wherein, The appliance includes the plurality of accessories, and each of the plurality of accessories is configured to cause a different capacitance response at the capacitance sensor.

8. The apparatus according to claim 7, wherein The main unit includes a first electrode, and each of the plurality of accessories includes a corresponding second electrode, each second electrode being different from each other second electrode.

9. The apparatus according to claim 8, wherein Each second electrode includes a cross-sectional area different from each other second electrode.

10. The apparatus according to claim 8 or 9, wherein, A first accessory of the plurality of accessories includes a first number of second electrodes, and a second accessory of the plurality of accessories includes a second number of second electrodes different from the first number of second electrodes.

11. The apparatus according to any one of claims 8 to 10, wherein, Data output by the capacitance sensor represents a capacitance value measured when a corresponding one of the plurality of accessories is attached to the main unit.

12. The apparatus according to any one of claims 8 to 11, wherein, The first electrode includes a plurality of first electrodes, and data output by the capacitance sensor represents the number of the plurality of first electrodes overlapping with its second electrode when a corresponding one of the plurality of accessories is attached to the main unit.

13. The apparatus according to claim 12, wherein, The plurality of first electrodes are arranged in a substantially circular array, each second electrode is arc-shaped, and the plurality of first electrodes and each second electrode are configured such that data output by the capacitance sensor depends on the rotational orientation of the accessory relative to the main unit.

14. The apparatus according to claim 12, wherein, The plurality of first electrodes are arranged in a substantially circular array, each second electrode is arc-shaped, and the plurality of first electrodes and each second electrode are configured such that data output by the capacitance sensor is constant for a given accessory, independent of the rotational orientation of the accessory relative to the main unit.

15. The appliance according to any one of claims 7 to 14, wherein, The main unit includes a first electrode and a first dielectric portion covering the first electrode, each of the plurality of accessories includes a corresponding second electrode and a corresponding second dielectric portion covering the second electrode, and each second dielectric portion is different from each other second dielectric portion.

16. The apparatus according to claim 15, wherein, Each second dielectric portion includes a thickness different from each other second dielectric portion.

17. The apparatus according to claim 15 or 16, wherein, The first dielectric portion is unevenly distributed on the first electrode.

18. The apparatus according to any one of claims 7 to 14, wherein Each of the plurality of accessories includes a corresponding second electrode and a corresponding second dielectric portion covering the second electrode, and each second dielectric portion is different from each other second dielectric portion.

19. The apparatus according to claim 7, wherein, The main unit includes a drive electrode and a receiver electrode, and each of the plurality of accessories includes a respective second electrode, each second electrode being different from every other second electrode.

20. The apparatus according to any one of the preceding claims, wherein, The appliance includes a transmitter configured to emit light radiation, an optical sensor configured to receive reflected light radiation from an object external to the appliance, and another control module configured to determine an attribute of the object based on another data output by the optical sensor.

21. The apparatus according to claim 20, wherein, The optical sensor includes a time-of-flight sensor.

22. The apparatus according to claim 20 or 21, wherein, The main unit includes a cylindrical portion having a central hole, the plurality of accessories being attachable to one end of the cylindrical portion, and at least one of the transmitter and the optical sensor being located within the hole.

23. The apparatus according to any one of the preceding claims, wherein, The appliance is a hair care appliance.

24. An accessory for a hair care appliance, the accessory including an interface portion configured to dock with a main unit of the hair care appliance, the interface portion including an electrode layer, wherein the electrode layer is exposed at the interface portion.

25. The accessory according to claim 24, wherein, The interface portion includes a dielectric layer covering the electrode layer such that the dielectric layer is exposed at the interface portion.

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