Hair dryer

Abstract

Provided is a hair dryer for generating an air flow. The hair dryer includes a heater (400) arranged for heating the air flow, and a fan unit (200) having an air inlet (210) arranged for drawing air into the fan unit (200), and an air outlet (230). The hair dryer further includes a duct (100) in which air blown from the air outlet (230) of the fan unit (200) is receivable. The duct (100) extends away from the air outlet (230) towards a downstream air guiding element (112). The downstream air guiding element (112) is arranged so that at least some of the air blown along the duct (100) is directed by the downstream air guiding element (112) across and / or towards the air inlet (210).

Description

FIELD OF THE INVENTION

[0001] The invention relates to a hair dryer.BACKGROUND OF THE INVENTION

[0002] Prior art hair dryers generally comprise a housing, an air inlet allowing air to enter the housing, a fan to move the air from the air inlet via a heater to an air outlet where heated air leaves the housing.

[0003] WO2022157056A1 discloses a hair dryer for generating an air flow, the hair dryer comprising a curved shape unit defining an outer surface of the hair dryer, a first part of the outer surface being at an angle to a desired direction of the air flow, and a second part of the outer surface being aligned with the desired direction of the air flow; a fan unit at the first part of the outer surface, the fan unit having an air inlet, and an air outlet arranged for blowing air along the first part of the outer surface; and a heater arranged for heating a user's hair.SUMMARY OF THE INVENTION

[0004] It is, inter alia, an object of the invention to provide alternative designs of a hair dryer, which may be more efficient than existing hair dryers. The invention is defined by the independent claims. Advantageous embodiments are defined in the dependent claims.

[0005] According to examples in accordance with an aspect of the present disclosure, there is provided a hair dryer for generating an air flow, the hair dryer comprising a fan unit having an air inlet arranged for drawing air into the fan unit, and an air outlet; a heater arranged for heating the air flow; and a duct in which air blown from the air outlet of the fan unit is receivable, the duct extending away from the air outlet towards a downstream air guiding element, the downstream air guiding element being arranged so that at least some of the air blown along the duct is directed by the downstream air guiding element across and / or towards the air inlet.

[0006] By directing, e.g. deflecting, at least some of the air blown along the duct across and / or towards the air inlet, the downstream air guiding element can assist recirculation of the air back into the fan unit.

[0007] Such recirculation can assist to reduce energy consumption, via re-use of thermal energy, so that more efficient hair drying can be achieved.

[0008] It is noted that directing at least some of the air blown along the duct across the air inlet can mean that the air is re-circulatable into the fan unit since, an air flow initially directed by the downstream air guiding element across the air inlet can be subsequently redirected, by operation of the fan unit, and drawn in the direction of the air inlet.

[0009] In some embodiments, the downstream air guiding element comprises a surface, e.g. an angled and / or curved surface, that faces across and / or towards the air inlet. The surface may be arranged to receive air blown along the duct and to direct the air received on the surface across and / or towards the air inlet. In such embodiments, at least some of the air blown along the duct can reach the surface and be deflected by the surface across and / or towards the air inlet.

[0010] Alternatively or additionally, the downstream air guiding element may extend towards an axis that is parallel or colinear with a rotation axis of the fan unit, about which rotation axis the fan unit's fan is rotatable to draw air into the air inlet and blow air from the air outlet. Such extension of the downstream air guiding element towards this axis can facilitate directing of said at least some of the air blown along the duct across and / or towards the air inlet.

[0011] It is noted that a front side of the hair dryer can constitute the side of the hair dryer towards which air is drawn towards the air inlet.

[0012] In some embodiments, the downstream air guiding element at least partially surrounds the air inlet, when the hair dryer is viewed from in front of the front side. Accordingly, air can be guided by the downstream air guiding element across and / or towards the air inlet from multiple positions around the air inlet, with concomitant air recirculation and efficiency benefits.

[0013] In some embodiments, the downstream air guiding element at least partially surrounds the air inlet so that at least part of the air inlet is located in-between opposite portions of the downstream air guiding element. Thus, air can be recirculated into the fan unit from positions that oppose each other across the air inlet.

[0014] Alternatively or additionally, the downstream air guiding element may be radially arranged around the air inlet, when the hair dryer is viewed from in front of the front side. Thus, air can be recirculated into the fan unit from different radial positions around the air inlet.

[0015] In other embodiments, the air inlet at least partially surrounds the downstream air guiding element, when the hair dryer is viewed from in front of the front side. Such a configuration may also provide efficiency benefits associated with assisting recirculation of air back into the fan unit.

[0016] In such embodiments, the air inlet can, for example, be radially arranged around the downstream air guiding element, when the hair dryer is viewed from in front of the front side.

[0017] It is generally noted that the duct and the downstream air guiding element can be formed in any suitable manner. In some embodiments, the hair dryer comprises a duct wall that at least partially delimits the duct, with the downstream air guiding element being included in, or extending from, the duct wall.

[0018] The hair dryer may comprise an air inlet grille whose inlet openings allow air to enter the fan unit via the air inlet. Such an air inlet grille can assist to avoid items accessing moving parts, such as fan blade(s) of the fan unit, within the hair dryer.

[0019] In such embodiments, the downstream air guiding element may be arranged so that at least some of the air blown along the duct is directed by the downstream air guiding element across and / or towards the air inlet grille.

[0020] In some embodiments, the air inlet grille has outwardly protruding region(s) that outwardly protrude towards the front side of the hair dryer, e.g. towards which front side air is drawn into the air inlet, and / or inwardly protruding region(s) that is / are inwardly recessed with respect to the front side of the hair dryer. Such a profile of the air inlet grille can assist to enable air to pass through the air inlet when hair is placed over the air inlet grille.

[0021] Alternatively, the air inlet grille may be a flat / planar air inlet grille. The flat hair-contacting surface of the flat / planar air inlet grille can assist in straightening / taming hair.

[0022] In some embodiments, the inlet openings comprise an arrangement of concentric annular slits. The concentric annular slits may, for example, be defined between dividing elements, with the dividing elements proximal to a periphery of the air inlet grille being more curved towards the downstream air guiding element than the dividing elements at or proximal to a center of the air inlet grille. This curved dividing elements design can follow the (primary) flow of air guided by the downstream air guiding element to reduce sound and drag. Moreover, this design can mean that the air flow direction is adjusted for optimal reflow / recirculation and reach of the air flow towards the hair.

[0023] In some embodiments, the dividing elements at or proximal to the periphery of the air inlet grille can guide air from the downstream air guiding element into the concentric annular slits at or proximal to the periphery of the air inlet grille.

[0024] The heater included in the hair dryer can heat the air prior to the air leaving the hair dryer. In some embodiments, the heater comprises a heating wire, a coil heating element, a ceramic heater, a light source or any combination of aforementioned heater.

[0025] A key challenge may be mounting the heater to minimize blocking of air flow. For example, a mica supporter for supporting the heater can risk blocking the air flow.

[0026] In some embodiments, the heater comprises a coil heating element. A heat resistant cord may be arranged within the coil heating element, with the heat resistant cord comprising attachment portions, e.g. loops, that protrude through windings of the coil heating element to reach the outside of the coil heating element. The attachment portions can attach to mounting members, e.g. hooks, arranged in the hair dryer around the coil heating element.

[0027] This can provide, in the context of the hair dryer according to the present disclosure, a relatively high performance, low weight and low-cost heater construction.

[0028] The coil heating element may be mounted via the heat resistant cord and the mounting members around a wall delimiting an interior space within the hair dryer.

[0029] The spacing along the heat resistant cord between neighboring attachment portions, e.g. loops, may determine the number of windings of the coil heating element per segment of the coil heating element, with each segment being arranged between neighboring mounting members.

[0030] In some embodiments, the fan unit comprises a centrifugal fan.

[0031] Such a centrifugal fan can provide a particularly effective / efficient blowing of air along the duct.

[0032] In some embodiments, the fan unit comprises a brushless DC motor, e.g. a flat brushless DC motor. Such a motor can have noise reduction benefits, as well as enabling the hair dryer to be made more compact.

[0033] In some embodiments, a motor, e.g. the flat brushless DC motor, of the fan unit is mounted at the back of the fan unit. This can provide a relatively spatially efficient solution for mounting the fan unit.

[0034] The hair dryer can comprise a handle for the user to grip.

[0035] The handle can facilitate use of the hair dryer, since the user can grasp the handle and apply the hair dryer to their hair (or someone else's hair in the scenario that the user is using the hair dryer to dry and / or style another person's hair).

[0036] In some embodiments, the handle is rotatable, e.g. freely rotatable, relative to a drying unit of the hair dryer. For example, the handle may be rotatable, e.g. freely rotatable, relative to a drying unit comprising the fan unit, the duct and the heater.

[0037] This may permit an upper (drying unit-comprising) and lower (handle-comprising) part of the hair dryer to be passively or actively aligned with a hair direction of hair being treated using the hair dryer.

[0038] In some embodiments, the hair dryer comprises a sensor for sensing temperature of the air flow at the air outlet of the hair dryer, and the heater is controlled according to the sensed temperature of the air flow. Such feedback control can assist to ensure that the air being applied to hair is appropriately heated.

[0039] Alternatively or additionally, the hair dryer can comprise a distance sensor for sensing the distance between the hair dryer and the hair when in use, and the heater is controlled according to the distance between the hair dryer and the hair. This can assist to ensure that the air being applied to hair is at an appropriate temperature upon reaching the hair.

[0040] In some embodiments, the hair dryer comprises a communication unit for communicating with a mobile device. This can assist to enhance user experience, for example by enabling the user to control and / or monitor usage of the hair dryer via their mobile device.

[0041] It is noted that the hair dryer can be used for hair styling, e.g. taming and / or straightening, in addition to hair drying.

[0042] In some embodiments, the hair dryer comprises hair styling element(s), e.g. detachable hair styling element(s), for styling hair.

[0043] In some embodiments, the hair dryer comprises a hair brush that includes bristles for brushing hair.

[0044] Alternatively or additionally, the hair dryer may include a topical and / or additive element for nurturing hair.

[0045] In some embodiments, the hair dryer comprises a battery to supply power to the hair dryer. Such a battery can facilitate use of the hair dryer, for instance by avoiding such use being hampered by a power cable that connects the hair dryer to an external, e.g. mains, power source.

[0046] The hair dryer can accordingly be a cordless hair dryer, e.g. a cordless hair dryer comprising detachable hair styling attachment(s).

[0047] In some embodiments, the battery may be included, e.g. stored, in the hair dryer's handle.

[0048] Including the battery in the handle can be beneficial for size- and weight-related reasons. However, this can reduce available space in the handle for housing electronics. Moreover, high performance hair dryers tend to require more control electronics for motor control.

[0049] In some embodiments, an intermediate part of the hair dryer is arranged between a first portion along which air is displaced by the fan unit in a first flow direction and a second portion along which air is displaced by the fan unit in a second flow direction different from the first flow direction.

[0050] In such embodiments, the intermediate part may contain at least one separator, e.g. wall, and one or both of control electronics and at least part of the fan unit, e.g. the motor.

[0051] Such accommodating of the control electronics and / or at least part of the fan unit in the intermediate part can free up space in a remainder of the hair dryer, for example to facilitate storage of a battery in the hair dryer's handle.

[0052] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.BRIEF DESCRIPTION OF THE DRAWINGS

[0053] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which: Fig. 1A schematically shows a side view of a hair dryer according to a first example; Fig. 1B schematically shows a rear view of the hair dryer shown in Fig.1A; Fig. 2 schematically shows a hair dryer according to a second example; Fig. 3 provides a perspective view of a drying unit of a hair dryer of the type shown in Fig. 2; Fig. 4 provides a schematic side view of part of a hair dryer according to a third example; Fig. 5 provides a schematic side view of part of a hair dryer according to a fourth example; Fig. 6 provides a schematic side view of part of a hair dryer according to a fifth example; Fig. 7 provides a schematic side view of part of a hair dryer according to a sixth example; Fig. 8 provides a schematic side view of a hair dryer according to a seventh example; Fig. 9 provides a schematic side view of a hair dryer according to an eighth example; Figs. 10 to 12 provide schematic views showing air inlet grilles of hair dryers according to further examples; Figs. 13 to 15 provide schematic views showing hair proximal to the air inlet grilles shown in Figs. 10 to 12; Fig. 16 provides an enlarged view of the example shown in Fig. 11, showing dividing elements that define annular slits provided in the air inlet grille; Fig. 17 schematically depicts a control electronics-containing intermediate part of a hair dryer according to an example; Fig. 18 shows a heater according to an example; Fig. 19 schematically depicts mounting of the heater shown in Fig. 18 in the hair dryer; Fig. 20 shows a heat resistant cord and mounting members for mounting a coil heating element of the heater shown in Figs. 18 and 19, but with the coil heating element itself being omitted from Fig. 20; and Fig. 21 shows the heat resistant cord and mounting members shown in Fig. 20, together with the coil heating element. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] The invention will be described with reference to the Figures.

[0055] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0056] Provided is a hair dryer for generating an air flow. The hair dryer comprises a heater for heating the air flow, and a fan unit having an air inlet arranged for drawing air into the fan unit, and an air outlet. The hair dryer further includes a duct in which air blown from the air outlet of the fan unit is receivable. The duct extends away from the air outlet towards a downstream air guiding element. The downstream air guiding element is arranged so that at least some of the air blown along the duct is directed by the downstream air guiding element across and / or towards the air inlet.

[0057] Fig. 1A and Fig. 1B show a side view and a rear view, respectively, of a hair dryer according to an example. It is to be understood that the drawings are just rough sketches for the purpose of illustrating principles of the present disclosure.

[0058] The hair dryer comprises a duct 100, a fan unit 200 and a heater 400 for heating air. The duct 100 receives, and carries downstream, air blown from the fan unit 200. The duct 100 can be formed in any suitable manner. As shown in Fig. 1A, a duct wall 111 at least partially delimits the duct 100.

[0059] The fan unit 200 comprises an air inlet 210 arranged for drawing air into the fan unit 200, and an air outlet 230. Part of the air flow being directed into the air inlet 210 is represented in Fig. 1A by arrow FD. With continued reference to Fig. 1A, the duct 100 extends away from the air outlet 230 towards a downstream air guiding element 112.

[0060] The downstream air guiding element 112 is arranged so that at least some of the air blown along the duct 100 is directed by the downstream air guiding element 112 across and / or towards the air inlet 210 (see the arrow SD in Fig. 1A). By directing, e.g. deflecting, at least some of the air blown along the duct 100 across and / or towards the air inlet 210, the downstream air guiding element 112 can assist recirculation of the air back into the fan unit 200. Such recirculation can assist to reduce energy consumption, via re-use of thermal energy, so that more efficient hair drying can be achieved.

[0061] It is noted that directing at least some of the air blown along the duct 100 across the air inlet 210 can mean that the air is re-circulatable into the fan unit 200 since, an air flow initially directed by the downstream air guiding element 112 across the air inlet 210 can be subsequently redirected, by operation of the fan unit 200, and drawn in the direction of the air inlet 210.

[0062] In some embodiments, and still referring to Fig. 1A, the downstream air guiding element 112 comprises a surface 112A, e.g. an angled and / or curved surface 112A, that faces across and / or towards the air inlet 210. The surface 112A may be arranged to receive air blown along the duct 100 and to direct the air received on the surface 112A across and / or towards the air inlet 210. In such embodiments, at least some of the air blown along the duct 100 can reach the surface 112A and be deflected by the surface 112A across and / or towards the air inlet 210.

[0063] Alternatively or additionally, the downstream air guiding element 112 may extend towards an axis A1 that is parallel or colinear with a rotation axis of the fan unit 200, about which rotation axis the fan unit's 200 fan is rotatable to draw air into the air inlet 210 and blow air from the air outlet 230. Such extension of the downstream air guiding element 112 towards this axis A1 can facilitate directing of said at least some of the air blown along the duct 100 across and / or towards the air inlet 210.

[0064] In some embodiments, such as shown in Fig. 1A, the downstream air guiding element 112 is included in, in other words forms part of, the duct wall 111.

[0065] In other embodiments, the downstream air guiding element 112 extends from an end of the duct wall 111 at which the duct 100 terminates. In other words, the downstream air guiding element 112 may extend away from a duct outlet 113. In such embodiments, the downstream air guiding element 112 may be arranged to direct at least some of the air that has exited the duct outlet 113 across and / or towards the air inlet 210.

[0066] In some embodiments, and regardless of whether or not the air guiding element 112 is included in, or extends away from, the duct wall 111, the duct outlet 113 may be provided with grille elements 114 (see Fig. 3). In such embodiments, the duct outlet 113 can be regarded as an air outlet grille of the hair dryer.

[0067] It is also generally noted, with reference to Figs. 1A, 2 and 3, that a front side FS of the hair dryer can constitute the side of the hair dryer towards which air is drawn towards the air inlet 210. A back side BS of the hair dryer faces away from the front side FS. It is reiterated that Fig. 1B shows the hair dryer when viewed from the back side BS.

[0068] In some embodiments, and as shown in Fig. 1A, a surface 120 of the duct wall 111 that faces away from the interior of the duct 100 can delimit an inner cavity 130 and a central opening 140 for allowing air to enter the air inlet 210 of the fan unit 200. The central opening 140 may have any suitable shape, such as a round shape, square shape, etc.

[0069] The position of the opening 140 can be aligned with the air inlet 210. The term "align" in this context means from front view or rear view, the opening 140 and the air inlet 210 share an at least partially overlapping area. In some embodiments, the fan unit 200 partially protrudes inwardly to the inner cavity 130 through the opening 140 such that the air inlet 210 is within the inner cavity 130.

[0070] In embodiments in which the surface 120 of the duct wall 111 delimits the inner cavity 130, the downstream air guiding element 112 may be arranged so that at least some of the air blown along the duct 100 is directed by the downstream air guiding element 112 across and / or into the inner cavity 130.

[0071] More generally, and referring to Figs. 1A, 1B and 2, the hair dryer may include a handle 300 for the user to grip. Such a handle-comprising hair dryer can be regarded as a handheld hair dryer.

[0072] The handle 300 can facilitate use of the hair dryer, since the user can grasp the handle 300 and apply the hair dryer to their hair (or someone else's hair in the scenario that the user is using the hair dryer to dry and / or style another person's hair).

[0073] In some embodiments, the handle 300 is freely rotatable relative to a drying unit 500 of the hair dryer (see Fig. 3). For example, the handle 300 may be freely rotatable relative to a drying unit 500 comprising the fan unit 200, the duct 100 and the heater 400.

[0074] This may permit an upper (drying unit-comprising) part and lower (handle-comprising) part of the hair dryer to be passively or actively aligned with a hair direction of hair being treated using the hair dryer.

[0075] As also shown in Fig. 1A, the heater 400 included in the hair dryer can heat the air prior to the air leaving the hair dryer. In some embodiments, such as shown in Fig. 1A, the heater 400 is arranged upstream of the air inlet 210, such that the air is heated prior to entering the fan unit 200 via the air inlet 210. The heater 400 may, for example, be positioned in the inner cavity 130. In other embodiments, the heater 400 is arranged downstream of the air outlet 230, for example in the duct 100, such that the air is heated after exiting the fan unit 200 via the air outlet 230.

[0076] In some embodiments, such as shown in Fig. 1A, the heater 400 comprises a heating wire 401 wound around a supporter 402. Preferably, the supporter 402 is mounted in the inner cavity 130 adjacent to the opening 140 and is co-axial with the opening 140. As a result, the air can be heated before the air is drawn into the fan unit 200. Alternatively, the heater 400 may be another type of heater 400, such as a ceramic heater, PTC heater, a light source, or a combination of different types of heaters 400.

[0077] In some embodiments, such as shown in Figs. 1A and 2 to 6, the downstream air guiding element 112 at least partially surrounds the air inlet 210, when the hair dryer is viewed from in front of the front side FS. Accordingly, air can be guided by the downstream air guiding element 112 across and / or towards the air inlet 210 from multiple positions around the air inlet 210, with concomitant air recirculation and efficiency benefits.

[0078] In such embodiments, the downstream air guiding element 112 may, for example, at least partially surround the air inlet 210 so that at least part of the air inlet 210 is located in-between opposite portions P1, P2 of the downstream air guiding element 112. Thus, air can be recirculated into the fan unit 200 from positions that oppose each other across the air inlet 210.

[0079] Alternatively or additionally, and as best shown in Fig. 3, the downstream air guiding element 112 may be radially arranged around the air inlet 210, when the hair dryer is viewed from in front of the front side FS. Thus, air can be recirculated into the fan unit 200 from different radial positions around the air inlet 210.

[0080] In other embodiments, and referring now to Figs. 7 to 9, the air inlet 210 at least partially surrounds the downstream air guiding element 112, when the hair dryer is viewed from in front of the front side FS. Such a configuration may also provide efficiency benefits associated with assisting recirculation of air back into the fan unit 200.

[0081] In such embodiments, the air inlet 210 can, for example, be radially arranged around the downstream air guiding element 112, when the hair dryer is viewed from in front of the front side FS.

[0082] In some embodiments, and as best shown in Figs. 10 to 16, the hair dryer comprises an air inlet grille 211A, 211B, 211C whose inlet openings allow air to enter the fan unit 200 via the air inlet 210. Such an air inlet grille 211A, 211B, 211C can assist to avoid items accessing moving parts, such as fan blade(s) of the fan unit 200, within the hair dryer.

[0083] The inlet openings may be dimensioned, e.g. as mandated by IEC 61032, to avoid the user's fingers from being able to pass through the inlet openings and reach moving part(s) of the hair dryer.

[0084] The air inlet grille 211A, 211B, 211C may also be arranged to optimize the above-described air recirculation and / or to prevent hair blocking of the air inlet 210, as well as permitting the air inlet grille 211A, 211B, 211C to approach the hair HA as closely as possible so as to enable fast and proper drying / styling. The air inlet grille 211A, 211B, 211C may furthermore be a source of drag (and thus a cause of lower efficiency), as well as a cause of increased sound.

[0085] Accordingly, the air inlet grille 211A, 211B, 211C may be a key element in the hair dryer's design.

[0086] The outer curvature or shape of the air inlet grille 211A, 211B, 211C and / or the inlet shape / pattern of the inlet openings through which air flows can be considered.

[0087] The outer curvature or shape can be related to positioning the hair HA and lessening the risk of blocking of the air inlet 210. In this respect, if the air inlet grille 211A, 211B, 211C is blocked, the air outlet 230 may not expel sufficient air to push away the hair HA. Subsequently the heater 400, if not controlled, can overheat, and the hair dryer may fail.

[0088] Therefore, the air outlet 230 may be configured to deliver sufficient air flow to push away the hair HA, and the air inlet 210 may be configured to draw enough air to pull hair HA towards the air inlet 210, but not so as to provide a higher suction force than the blowing force. In other words, the force on hair HA from the air outlet 230 may need to be larger than the force on hair HA (wet or dry) due to lower pressure provided at the air inlet 210 once the hair HA is pushed onto the air inlet grille 211A, 211B, 211C.

[0089] Figs. 4, 10 and 15 schematically depict an outwardly curved air inlet grille 211A, whose curvature causes a central region of the air inlet grille 211A to protrude, relative to a peripheral region of the air inlet grille 211A, towards the front side FS of the hair dryer (towards which front side FS air is drawn into the air inlet 210).

[0090] Figs. 2, 5, 8, 11 and 13 schematically depict a planar, in other words flat, air inlet grille 211B. The flat hair-contacting surface of the flat / planar air inlet grille 211B can assist in straightening / taming hair HA.

[0091] Figs. 6, 12 and 14 schematically depict an inwardly curved air inlet grille 211C, whose curvature causes a central region of the air inlet grille 211C to be recessed, relative to a peripheral region of the air inlet grille 211C, away from the front side FS of the hair dryer.

[0092] The inwardly curved air inlet grille 211C (see Fig. 14) and the outwardly curved air inlet grille 211A (see Fig. 15) can assist to minimize the risk of the hair HA blocking the air inlet 210 compared to the planar air inlet grille 211B (see Fig. 13).

[0093] The shape of the outwardly curved air inlet grille 211A can mean that hair HA can only contact the air inlet grille 211A in a limited area, preferably where the air flow is lowest, for example in the central region of the air inlet grille 211A.

[0094] In the case of the inwardly curved air inlet grille 211C, the hair HA may be most likely to contact the peripheral region of the air inlet grille 211C, and thus the central region of the air inlet grille 211C can be left open for air to pass therethrough.

[0095] In embodiments in which the air outlet 230 is annular, e.g. circular, the outwardly curved inlet grille 211A or the inwardly curved inlet grille 211C may be preferred, for recirculation of air back into the air inlet 210.

[0096] In more general terms, and also referring to Figs. 7 and 9, the air inlet grille 211A, 211C can have outwardly protruding region(s) that outwardly protrude towards the front side FS of the hair dryer (towards which front side FS air is drawn into the air inlet 210), and / or inwardly protruding region(s) that is / are inwardly recessed with respect to the front side FS of the hair dryer.

[0097] Such a profile of the air inlet grille 211A, 211C can assist to enable air to pass through the air inlet 210 when hair HA is placed over the air inlet grille 211A, 211C.

[0098] The inlet shape / pattern of the inlet openings in the air inlet grille 211A, 211B, 211C is related to air drag, and hence is relevant to efficiency and sound. This inlet shape / pattern may be selected to create a desired overall air flow, allowing the air to reach further towards the hair HA before it is recirculated back into the air inlet 210. A reflow hair dryer, in which air is recirculated back into the air inlet 210, may be designed to direct air away from the hair dryer to dry hair HA, but also to collect air back into the air inlet 210 to reuse the heat.

[0099] In some embodiments, such as shown in Figs. 10 to 16, the inlet openings may comprise an arrangement of concentric annular slits.

[0100] In some embodiments, and as best shown in Fig. 16, the concentric annular slits may be defined between dividing elements 212, with the dividing elements 212 proximal to the periphery of the air inlet grille 211A, 211B, 211C being more curved towards the downstream air guiding element 112 than the dividing elements 212 at or proximal to the center of the air inlet grille 211A, 211B, 211C.

[0101] This curved dividing elements 212 design can follow the (primary) air flow pattern directed, initially, from the downstream air guiding element 112, and can be in line with air vectors, to reduce sound and drag. Moreover, this design can mean that the air flow direction is adjusted for optimal reflow / recirculation and reach towards the hair HA. Fig. 16 schematically shows how the dividing elements 212 can enable air flow optimization to allow reflow to happen with less or without losses and to get more flow out away from the hair dryer and back into the air inlet 210.

[0102] In some embodiments, and still referring to Fig. 16, the dividing elements 212 at or proximal to the periphery of the air inlet grille 211A, 211B, 211C can guide air from the downstream air guiding element 112 into the concentric annular slits at or proximal to the periphery of the air inlet grille 211A, 211B, 211C.

[0103] More generally, the fan unit 200 can have any suitable design. In some embodiments, the fan unit 200 is a centrifugal fan.

[0104] Referring again to Fig. 1A, the fan unit comprises a motor 220. The motor 220 of the fan unit 200 may be positioned at the back of the fan unit 200 as shown in Fig. 1A. Alternatively, the motor 220 may be positioned at the front of the fan unit 200, or at the center of the fan unit 200, or any other suitable position as long as it can draw air in through the air inlet 210 and blow air out through the air outlet 230. It is to be understood that the term "front" in the context of the present disclosure means the side that faces the user or is closer to the user than the "back". In the embodiment shown in Fig. 1A, the back of the fan unit 200 is at the right-hand side, while the front of the fan unit 200 is at the left-hand side.

[0105] In some embodiments, the hair dryer comprises a sensor (not shown in the Figures) for sensing temperature of the air flow at the air outlet 230 of the hair dryer. The temperature sensor may be an infrared temperature sensor, or any other type of temperature sensor known in the art. As mentioned above, the hair dryer according to the present disclosure may recirculate the hot air, therefore, the hair dryer may need less power. With the temperature sensor, it allows the heater 400 to be controlled according to the sensed temperature of the air flow.

[0106] When in use, the distance between the hair dryer and the hair HA may impact the amount of recirculated air flow. For example, the hot air might escape more when the hair dryer touches the hair HA. The hair dryer according to some embodiments comprises a distance sensor (not shown in the Figures) for sensing the distance between the hair dryer and the hair HA when in use. The distance sensor may be any type known in the art, for example, infrared distance sensor, laser-based distance sensor, ultrasound distance sensor, camera-based distance sensor, etc. The heater 400 thus may be controlled based on the distance between the hair dryer and the hair HA when in use.

[0107] Optionally, the hair dryer comprises a communication unit (not shown in the Figures) for communicating with a mobile device, and hence the sensing signal may be sent from the hair dryer to the mobile device and the control signal may be sent from the mobile device to the hair dryer.

[0108] Optionally, because of the recirculated hot air, less power may be needed, and the hair dryer may only comprise a battery (not shown in the Figures) to supply power to the hair dryer. The battery may be a replaceable battery or a rechargeable battery. In other words, reflow hair dryers, in which air is recirculated back into the fan unit's 200 air inlet 210 so as to enable thermal energy to be reused, can be battery powered.

[0109] In some embodiments, the battery, e.g. replaceable battery or a rechargeable battery, may be included in the handle 300.

[0110] Including the battery in the handle 300 can be beneficial for size- and weight-related reasons. However, this can reduce available space in the handle 300 for housing electronics. Moreover, high performance hair dryers tend to require more control electronics for motor control.

[0111] Accordingly in some embodiments, and referring to Fig. 17, an intermediate part of the hair dryer is arranged between a first portion along which air is displaced by the fan unit 200 in a first flow direction 600 and a second portion along which air is displaced by the fan unit 200 in a second flow direction 601 different from the first flow direction 600.

[0112] In such embodiments, the intermediate part may contain at least one separator 602, 603, e.g. wall, and one or both of control electronics 604 and at least part of the fan unit 200, e.g. the motor 220. Such accommodating of the control electronics 604 and / or at least part of the fan unit 200 in the intermediate part can free up space in a remainder of the hair dryer, for example to facilitate storage of a battery in the hair dryer's handle 300.

[0113] In some embodiments, and still referring to Fig. 17, the control electronics 604, the motor 220 and / or the heater 400 can be arranged in an inner cavity 630 of the hair dryer.

[0114] Regarding the heater 400, a key challenge may be mounting the heater 400 to minimize blocking of air flow. For example, a mica supporter 402 for supporting the heater 400, e.g. the heating wire 401 thereof, can risk blocking the air flow.

[0115] In some embodiments, and referring now to Figs. 18 to 21, the heater 400 comprises a coil heating element 410. A heat resistant cord 411 may be arranged within the coil heating element 410, with the heat resistant cord 411 comprising attachment portions 412, e.g. loops, that protrude through windings of the coil heating element 410 to reach the outside of the coil heating element 410. The attachment portions 412 can attach to mounting members 413, e.g. hooks, arranged in the hair dryer around the coil heating element 410.

[0116] This can provide, in the context of the hair dryer according to the present disclosure, a relatively high performance, low weight and low-cost heater 400 construction.

[0117] The coil heating element 410 may be mounted via the heat resistant cord 411 and the mounting members 413 around a wall delimiting an interior space within the hair dryer, e.g. around the inner cavity 130. For example, the mounting members 413 may be arranged around the surface 120 of the duct wall 111 that faces away from the interior of the duct 100.

[0118] The spacing along the heat resistant cord 411 between neighboring attachment portions 412, e.g. loops, may determine the number of windings of the coil heating element 410 per segment of the coil heating element 410, with each segment being arranged between neighboring mounting members 413.

[0119] In some embodiments, and referring to Fig. 19, the heat resistant cord 411 is arranged within the coil heating element 410 by being fed through a center of the coil heating element 410 (see step 414 in Fig. 19). The heat resistant cord 411 may be bound together, e.g. by joining free ends 415, 416 of the heat resistant cord 411 to each other (see step 417 in Fig. 19).

[0120] Once the heat resistant cord 411 is bound together in a defined circle, the heat resistant cord 411, together with the coil heating element 410, can be mounted via the attachment portions 412, e.g. loops, attaching to the mounting members 413, e.g. hooks.

[0121] This may pull out the coil heating element 410 in a defined pitch. In this way, the requirement for an internal or relatively large external mica supporter 402 can be obviated.

[0122] Fig. 20 schematically depicts spanning of the heat resistant cord 411 (without showing the coil heating element 410) so that the attachment portions 412, e.g. loops, attach to the mounting members 413, e.g. hooks. Fig. 21 shows the thus spanned heat resistant cord 411 together with the coil heating element 410.

[0123] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. Measures recited in mutually different dependent claims may advantageously be used in combination. That is, the mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to".

Claims

1. Hair dryer for generating an air flow, the hair dryer comprising: a fan unit (200) having an air inlet (210) arranged for drawing air into the fan unit (200), and an air outlet (230); a heater (400) arranged for heating the air flow; and a duct (100) in which air blown from the air outlet (230) of the fan unit (200) is receivable, the duct (100) extending away from the air outlet (230) towards a downstream air guiding element (112), the downstream air guiding element (112) being arranged so that at least some of the air blown along the duct (100) is directed by the downstream air guiding element (112) across and / or towards the air inlet (210).

2. Hair dryer as claimed in claim 1, wherein the downstream air guiding element (112) comprises a surface (112A) that faces across and / or towards the air inlet (210), the surface (112A) being arranged to receive air blown along the duct (100) and to direct the air received on the surface (112A) across and / or towards the air inlet (210).

3. Hair dryer as claimed in claim 1 or claim 2, wherein the downstream air guiding element (112) extends towards an axis (A1) that is parallel or colinear with a rotation axis of the fan unit (200), about which rotation axis the fan unit's (200) fan is rotatable to draw air into the air inlet (210) and blow air from the air outlet (230).

4. Hair dryer as claimed in any of claims 1 to 3, comprising a duct wall (111) that at least partially delimits the duct (100), the downstream air guiding element (112) being included in, or extending from, the duct wall (111).

5. Hair dryer as claimed in any of claims 1 to 4, comprising a front side (FS), towards which front side (FS) air is drawn towards the air inlet (210), wherein the downstream air guiding element (112) at least partially surrounds the air inlet (210), when the hair dryer is viewed from in front of the front side (FS).

6. Hair dryer as claimed in claim 5, wherein the downstream air guiding element (112) at least partially surrounds the air inlet (210) so that at least part of the air inlet (210) is located in-between opposing portions (P1, P2) of the downstream air guiding element (112), when the hair dryer is viewed from in front of the front side (FS).

7. Hair dryer as claimed in claim 5 or claim 6, wherein the downstream air guiding element (112) is radially arranged around the air inlet (210), when the hair dryer is viewed from in front of the front side (FS).

8. Hair dryer as claimed in any of claims 1 to 7, comprising a front side (FS), towards which front side (FS) air is drawn towards the air inlet (210), wherein the air inlet (210) at least partially surrounds the downstream air guiding element (112), when the hair dryer is viewed from in front of the front side (FS).

9. Hair dryer as claimed in claim 8, wherein the air inlet (210) is radially arranged around the downstream air guiding element (112) when the hair dryer is viewed from in front of the front side (FS).

10. Hair dryer as claimed in any of the preceding claims, comprising an air inlet grille (211A, 211B, 211C) having inlet openings for allowing air to enter the fan unit (200) via the air inlet (210).

11. Hair dryer as claimed in claim 10, wherein the downstream air guiding element (112) is arranged so that at least some of the air blown along the duct (100) is directed by the downstream air guiding element (112) across and / or towards the air inlet grille (211A, 211B, 211C).

12. Hair dryer as claimed in claim 10 or claim 11, wherein the air inlet grille (211A, 211C) has outwardly protruding region(s) that outwardly protrude towards the hair dryer's front side (FS), and / or inwardly protruding region(s) that is / are inwardly recessed with respect to the hair dryer's front side (FS).

13. Hair dryer as claimed in claim 10 or claim 11, wherein the air inlet grille (211B) is a flat air inlet grill (211B).

14. Hair dryer as claimed in any of claims 10 to 13, wherein the inlet openings comprise an arrangement of concentric annular slits.

15. Hair dryer as claimed in any of the preceding claims, wherein the heater (400) comprises a heating wire, a coil heating element, a ceramic heater, and / or a light source.

16. Hair dryer as claimed in any of the preceding claims, wherein the heater (400) comprises a coil heating element (410), wherein a heat resistant cord (411) is arranged within the coil heating element (410), the heat resistant cord (411) comprising attachment portions (412) that protrude through windings of the coil heating element (410) to reach the outside of the coil heating element (410), and wherein the attachment portions (412) attach to mounting members (413) arranged in the hair dryer around the coil heating element (410).

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