Device for treating the hair

Abstract

The invention relates to a device for treating the hair (1) with a movement of a handpiece (2) of the device along a lock of hair from a root to a tip, the handpiece (2) being elongate along a longitudinal axis (X), and comprising: two arms (5, 6) that are rotatable relative to one another about an axis of rotation (R) via an articulation (8) and each bearing a jaw (3, 4), the jaws (3, 4) being able to take up an open configuration and a closed configuration, an inertial sensor (30) arranged at a distance (C) from the axis of rotation (R) of less than 20% relative to the length (L) of the handpiece (2) along the longitudinal axis (X), the inertial sensor (30) being configured to generate information on motion of the handpiece (2).

Description

[0001] Description

[0002] Title: Device for treating the hair

[0003] The present invention relates to devices for treating the hair, and more particularly, but not exclusively, those intended for shaping the hair, in particular for curling and / or straightening the hair.

[0004] The invention relates more particularly to straightening and / or curling devices having two jaws that are movable relative to one another and are able to adopt a spaced-apart configuration for introducing a lock of hair between said jaws and a moved-together configuration for treating the lock.

[0005] Technical field

[0006] Numerous devices of this type have already been proposed. These devices generally comprise internal heating plates between which the locks can be gripped, in particular in the case of straightening, and / or heating plates on the external surfaces thereof, around which the locks of hair are wound, in particular in the case of curling or at least making the locks wavy.

[0007] Usually, devices of this type are made up of two arms that are connected together using an articulation that allows said arms to open and close, and at least one heating element arranged on one of the arms. During operations for styling a lock of hair, said lock of hair is introduced between the two arms in the open position and then the two arms are manually closed over the lock of hair. This lock of hair is then heated by the heat emitted by the one or more heating elements until the two arms are opened and the lock of hair is removed.

[0008] These devices are generally used by moving the device from the root to the tip of the hair, with the lock wound around the device or not, depending on the desired result and the type of device.

[0009] WO 2021 / 102751 proposes a device comprising heating plates and a gyroscope measuring the posture and the motion of the device. The gyroscope makes it possible to send motion or posture information to a processor that cuts off the power supply in the absence of motion or generates an audible and / or visual and / or vibrating warning signal according to the motion or posture detected in order to improve the user experience. This application does not specify the position of the gyroscope on the device.

[0010] CN 109288230 proposes a hair straightener comprising a module for detecting the posture of the device, for example an accelerometer or a gyroscope. The device is capable of determining whether the current posture is within a range of acceptable postures for carrying out satisfactory treatment. If the posture is incorrect, a warning is sent to the user so that they can correct their posture, for example a sound or a vibration. This application does not specify the position of the posture detection module on the straightener.

[0011] WO 2019 / 122838 describes a system making it possible to detect the motion of a hair straightener in order to determine whether the motion of the device is in accordance with the desired treatment, in particular with respect to the speed of use. This application does not specify the position of the motion detector on the straightener.

[0012] EP 2359710 proposes a device comprising heating plates and a motion sensor, for example an accelerometer or an optical sensor. The motion sensor makes it possible to send an audible and / or visual warning as a function of the motion detected, in particular as a function of the speed of movement. For example, if the speed of movement is too fast or too slow, a warning signal is emitted. The motion sensor is located at the heating plates. During the movement of the device, the arms of the device are likely to be opened or closed and this opening or closing can cause the sensor to detect a parasitic motion that distorts the measurement.

[0013] Hair treatment devices which include heating plates that are switched on and / or off according to the motions detected are known from KR10-2021-0016993, KR10-2017- 0122407 and WO2016 / 161259. The positions of the motion detectors are not specified.

[0014] US20170231353 describes a device comprising a motion sensor, in particular of accelerometer or gyroscope type, in the grip portion for moving a heating portion by means of a motor in order to follow the motions of the user’s hand.

[0015] EP3178347 detects a rotational motion of the device by a rotation or acceleration sensor in a grip portion in order to trigger certain actions on the device in a cooling zone.

[0016] There is a need to improve hair treatment devices comprising two arms that can take up an open or closed configuration, in particular to increase the accuracy of motion detection by limiting the influence of parasitic motions.

[0017] Summary of the invention

[0018] The present invention meets this need by virtue of, according to one of its aspects, a device for treating the hair, in particular for curling and / or straightening the hair, with a movement of a handpiece of the device along a lock of hair from a root to a tip, the handpiece being elongate along a longitudinal axis, and comprising: two arms that are rotatable relative to one another about an axis of rotation via an articulation at one of their ends, each bearing a jaw for treating the hair, the jaws being able to take up an open configuration for engaging the hair between them and a closed configuration for treatment, by moving the arms relative to one another, an inertial sensor arranged along the longitudinal axis of the handpiece at a distance from the axis of rotation of less than 20%, better still less than 10%, even better still less than 5% relative to the length of the handpiece measured along the longitudinal axis of the handpiece, the inertial sensor being configured to generate information on motion of the handpiece.

[0019] The fact that the sensor is close to the articulation makes it possible to reduce parasitic motions associated with the motion of the arms relative to one another that could be detected with the inertial sensor. This is because the amplitude of parasitic motion is greater at the ends of the arms than close to the articulation.

[0020] Moreover, the hand of the user, when the device is in use, is close to the articulation to allow the jaws to be closed manually. The sensor therefore allows precise detection of movements, motion and / or positions of the hand.

[0021] Moreover, compared to a device having such a sensor in a handle in a position remote from the articulation, a position close to the articulation makes it possible to limit the parasitic motions associated with the tilting of the device around the articulation, in particular by a motion of the wrist.

[0022] Such a position also makes it possible to limit the bulk at the treatment surfaces, the sensor being positioned away from these surfaces.

[0023] Preferably, the device is a device for shaping the hair, in particular for curling and / or straightening the hair.

[0024] Arms

[0025] Preferably, the two arms each comprise a half-handle on the articulation side and the treatment jaw extends between the half-handle and a free end of the handpiece. The articulation may extend at the proximal end of the two arms.

[0026] The articulation may be an elastic hinge, in particular configured to hold the two jaws in an open configuration in the absence of external stress.

[0027] The jaws may each have an internal treatment surface configured to face one another in the closed configuration of the jaws. Asymmetry

[0028] In the closed configuration of the jaws, the handpiece may be asymmetrical about at least one longitudinal median plane transverse to the internal treatment surface of at least one of the jaws. Alternatively, the handpiece is symmetrical about at least one longitudinal median plane transverse to the internal treatment surface of at least one of the jaws. The fact that handpiece is asymmetrical about at least one longitudinal median plane has the effect that the treatment of the hair is asymmetrical during use of the device, in other words, separating the treatment into two parts of equal duration, for movement at a constant speed of the handpiece, the second part of the treatment is different from the reverse of the first part of the treatment. The treatment is thus different in a first and a second direction of use. As a result, this asymmetry of the device generates different treatment effects on the lock of hair depending on whether the handpiece is used in a first or the second direction of use. Such asymmetrical treatment may in particular lead to sub-optimal treatment when the direction of use is not as prescribed, that is, treatment of a lower quality than the device can provide when it is used correctly in an optimal direction of use.

[0029] Detection of the closure of the jaws

[0030] The device may comprise a member for detecting the configuration of the jaws, configured to detect whether the jaws are in the closed or open configuration, in particular a Hall effect sensor. The detection member may be arranged at the jaws or at the grip portion of the arms.

[0031] The detection member may be configured to discern between at least two jaw states, notably an open configuration and a closed configuration of the jaws, the closed configuration being a configuration in which the longitudinal axes of the arms form between them an angle which is smaller than a closure threshold angle.

[0032] Treatment member

[0033] At least one of the jaws may include at least one internal treatment member defining the internal treatment surface configured to come into contact with or face a portion of the lock of hair during treatment.

[0034] At least one of the arms may comprise at least one external treatment member comprising an external treatment surface configured to come into contact with a portion of the lock of hair during treatment, the external treatment surface notably being adapted to carry out a thermal treatment, being in particular a heating plate. The external treatment member may in particular make it possible to curl the hair by winding the hair around the handpiece and / or around one or each jaw.

[0035] The treatment member may comprise a heating plate, a steam applicator, a cosmetic applicator or a comb.

[0036] Inertial sensor

[0037] The inertial sensor may be a gyroscope, an accelerometer or a housing comprising a combination of one or more gyroscopes and / or one or more accelerometers, in particular an inertial unit.

[0038] The device may be configured so that the inertial sensor generates handpiece motion information only when the jaws are in the closed configuration. Operation of the inertial sensor may be blocked when the jaws are in the open configuration, for example by cutting off the power supply.

[0039] The inertial sensor may be configured to generate motion information in a reference frame formed by three axes that are fixed in space or movable with the handpiece, in particular with respect to three detection axes, at least one of which is parallel to the longitudinal axis of the handpiece, to the axis of rotation of the arms or an axis extending between the arms in the closed configuration of the jaws at least partially from the front face to the rear face of the handpiece.

[0040] The motion information may be: a parameter relating to motion, in particular a movement of the handpiece from a first position to a second position, a motion in a given direction of the handpiece, a speed of motion of the handpiece in at least one direction, a distance travelled by the handpiece and / or an acceleration or deceleration of the handpiece in at least one direction, and / or a parameter relating to a change of orientation of the handpiece, in particular rotation of the handpiece about at least one axis or an orientation of the handpiece in the fixed reference frame.

[0041] The parameter relating to motion, specifically the movement, speed and / or acceleration or deceleration, may be measured along an axis not parallel to the longitudinal axis of the handpiece, in particular along an axis perpendicular to the longitudinal axis of the handpiece, preferably parallel to a median plane extending between the jaws in the closed configuration of the jaws, in particular extending between the arms in the closed configuration of the jaws at least partially from the front face to the rear face of the handpiece.

[0042] The parameter relating to a change of orientation, specifically the rotation or orientation, may be measured in the reference frame fixed in space, in particular in relation to the horizontal, or around a fixed axis of the handpiece, in particular an axis substantially parallel to the longitudinal axis of the handpiece, and in relation to a fixed reference axis in the fixed reference frame, in particular a horizontal or vertical axis.

[0043] The inertial sensor may be configured to generate the motion information continuously in real time, notably when its activation is triggered. Activation of the inertial sensor may be triggered between two predetermined events.

[0044] The two predetermined events may be:

[0045] - the transition to the closed configuration of the jaws, signifying in particular the start of treatment of a lock of hair and / or positioning at the root of a lock of hair, and the transition to the open configuration of the jaws, signifying in particular the end of treatment and / or positioning of the device at the tip of a lock of hair,

[0046] - the transition to the closed configuration of the jaws, signifying in particular the start of treatment of a lock of hair and / or positioning at the root of a lock of hair, and the detection of contact of the two jaws with one another by a contact sensor positioned on the jaws, signifying in particular the absence of hair between the jaws and therefore positioning downstream of the tip of the lock of hair,

[0047] - the detection of the beginning of rotation of the handpiece about a fixed axis of the handpiece in one direction of rotation and the detection of the end of rotation of the handpiece about the fixed axis of the handpiece in said direction of rotation, and / or

[0048] - the detection of the start of movement of the handpiece in a predetermined direction, in particular by detecting a movement in one direction at a speed in that direction greater than a minimum reference speed, and the end of movement of the handpiece in the predetermined direction, in particular by detecting a change in direction of movement of the handpiece and / or a change in speed of the handpiece in said direction. Position of the inertial sensor

[0049] The inertial sensor is preferably at a non-zero distance from the nearest edge of the internal treatment member along the longitudinal axis.

[0050] The inertial sensor may extend on the opposite side of the articulation from the jaws.

[0051] The inertial sensor may extend at the proximal end of the handpiece.

[0052] The inertial sensor may be integrated in the handpiece or in the cord, in particular at the point where it is connected to the handpiece.

[0053] The handpiece may include a housing in which the inertial sensor is integrated.

[0054] Processor

[0055] The device may comprise a processor, in particular of microcontroller type, for determining at least one piece of usage information as a function at least of the motion information.

[0056] The processor may determine coordinates of a position of the sensor of the handpiece in a reference system fixed in space, in particular a geodetic system, on the basis of the motion information and known reference location information. Alternatively or in addition, the processor may determine a distance to a known reference location.

[0057] The processor may be configured to determine a direction of use of the handpiece at least between a first and a second direction of use on the basis of the detected handpiece motion information, so as to generate information on the direction of use of the device detected.

[0058] During treatment, the handpiece may have a first direction of use in which the lock moves from a front face to an opposite rear face of the handpiece, and a second direction of use in which the lock travels through the device from said rear face to the opposite front face. Detecting the direction of use therefore makes it possible to identify the treatment applied to the lock of hair. This makes it possible in particular to obtain treatment of the lock of hair that is desired and easily reproducible.

[0059] The processor may be configured to determine the orientation of the handpiece about an axis parallel to the longitudinal axis of the handpiece or an axis fixed in space, in particular a horizontal axis, which is advantageously representative of the direction of use of the handpiece. In particular, each direction of use may correspond to an orientation or a range of orientations of the handpiece, the orientations or the ranges of orientations preferably being different.

[0060] The processor may be configured to determine a distance of movement and / or an angle of rotation of the handpiece, in particular about a fixed axis of the handpiece, between two predetermined events, in particular from the above list, at least as a function of the motion information.

[0061] The processor may determine a length of a lock of hair, a position of the handpiece along the lock of hair, a position of the handpiece on the hair, a change in orientation of the handpiece along an axis parallel to the longitudinal axis of the handpiece or along another axis, or an orientation of the handpiece along an axis parallel to the longitudinal axis of the handpiece or along another axis, a change in direction of use of the handpiece, a change in speed of the handpiece, the start of treatment or the end of treatment and / or the stopping of the handpiece in the middle of treatment as a function of the motion information received.

[0062] The processor may determine whether the handpiece is used in a first mode of use or in a second mode of use on the basis of the motion information, the first and second modes of use being different to one another.

[0063] The processor may determine the speed of movement of the handpiece across the lock of hair on the basis of the motion information.

[0064] The processor may include a speed, position and / or motion estimation algorithm for processing the motion, position and / or orientation information from the inertial sensor. The algorithm may include a Madgwick filter or a learning model.

[0065] The device may include a user warning member configured to receive the handpiece motion information and / or the usage information determined by the processor on the basis of the motion information, in particular speed, position, rotation and / or distance to a reference point of the handpiece, and emit a user warning, in particular a signal perceptible to the user, notably an audible, visual or haptic signal as a function of the motion information.

[0066] The user warning member may be in or on the handpiece.

[0067] Alternatively, the user warning member may be separate to the handpiece. For example, the user warning member may be a phone or tablet connected wirelessly to the processor. The user warning emitted by the user warning member may correspond to one out of the first and second directions of use, in particular to a sub-optimal direction of use out of the first and second directions of use.

[0068] The user is thus quickly warned if they are using the device in the sub-optimal direction of use, which allows them to correct their use to move the handpiece in the optimal direction of treatment. The device thus makes it possible to simplify the use of the device, and make it more intuitive and ergonomic.

[0069] Cord

[0070] The device may include an at least electrical power cord attached to the handpiece. The power cord may be attached to the handpiece at an attachment arranged at a distance from the articulation of less than 10%, better still less than 5% of the length of the handpiece along the longitudinal axis.

[0071] The attachment between the handpiece and the power cord may be rotatable. This makes the handpiece easier to use by limiting how much the power cord gets in the way when the handpiece is rotated about the longitudinal axis of the handpiece.

[0072] The rotatable attachment of the power cord may extend on a half-handle of the handpiece, in particular a proximal end of the half-handle, for example a proximal end of a half-handle.

[0073] The rotatable attachment may extend at the articulation connecting two arms that are movable relative to one another between an open configuration for engaging the hair between them and a closed configuration for treatment.

[0074] The attachment of the cord to the handpiece may be rotatable substantially about the longitudinal axis of the handpiece, or about an axis forming a non-perpendicular angle relative to the longitudinal axis of the handpiece, but remaining in the longitudinal median plane transverse to the treatment surface.

[0075] “Substantially about the longitudinal axis’" means that the attachment is rotated about an axis forming, in a longitudinal plane, an angle of less than 20° to the longitudinal axis.

[0076] When the user changes the orientation of the handpiece, they perform a rotation relative to the earth’s horizontal about the longitudinal axis of the handpiece. Thus, having the attachment rotatable substantially about the longitudinal axis of the handpiece, or about an axis forming a non-perpendicular angle relative to the longitudinal axis of the handpiece, means that the rotatable attachment rotates when the orientation of the handpiece relative to the earth’s horizontal about the longitudinal axis of the handpiece is changed.

[0077] Alternatively, the device has no power cord and the handpiece comprises a battery on board the handpiece, in particular arranged on one of the arms. The battery may be rechargeable. The battery may be fixed or removable.

[0078] Method

[0079] The invention further relates, according to another aspect thereof, independently of or in combination with the above, to a method for treating the hair, in particular straightening or curling the hair, by moving a handpiece of a device as described above, along a lock of hair.

[0080] The method may include determining a direction of use or a mode of use of the device, in particular as a function of handpiece motion information generated by the inertial sensor.

[0081] The device may adopt a user warning configuration in which it emits a signal perceptible to the user, notably an audible, visual or haptic signal as a function of the handpiece motion information.

[0082] The device may comprise two jaws that can adopt a spaced-apart configuration of the jaws and a moved-together configuration of the jaws, in which method the device may adopt the warning configuration only when said jaws are in the moved-together configuration.

[0083] The method may include a step of determining the configuration of the jaws.

[0084] Preferably, the handpiece motion information is determined only if the configuration detected is the closed configuration.

[0085] The method may comprise treatment of the hair on an internal treatment surface of the handpiece, in particular a thermal surface, in particular a heating plate.

[0086] The method may comprise treatment of the hair on an external treatment surface of the handpiece, in particular a thermal surface, in particular a heating plate.

[0087] The method may comprise an additional treatment, in particular application of steam, application of a cosmetic product and / or combing.

[0088] Brief description of the drawings The invention may be understood more clearly on reading the following detailed description of non-limiting examples of the implementation of the invention, and on studying the appended drawing, in which

[0089] [Fig 1] Figure 1 shows a side view of an example of a device, and

[0090] [Fig 2] Figure 2 shows a perspective view of an alternative device.

[0091] Detailed description

[0092] Throughout the remainder of the description, elements that are identical or have identical functions bear the same reference signs. For the sake of conciseness in the present description, they are not described for each of the figures, with only the differences between the embodiments being described.

[0093] For the sake of clarity, the figures do not always show the actual proportions.

[0094] Figure 1 shows an example of a device 1, in this example for straightening the hair.

[0095] This device 1 has a handpiece 2 comprising two jaws 3 and 4 that are movable relative to one another about an axis of rotation between an open configuration for introducing a lock of hair between them, and a closed configuration for treatment.

[0096] The jaws 3 and 4 are held by an upper arm 5 and a lower arm 6 respectively, which, in the example in question, are connected to one another at one of their ends by an articulation 8, the handpiece 2 thus forming tongs.

[0097] The arms 5 and 6 define, between the articulation 8 and the jaws 3 and 4, respective half-handles 10 and 11, on which the user can press in order to move the jaws 3 and 4 together and thus grip the hair extending between the two jaws.

[0098] The width of the arms 5 and 6 at the half-handles 10 and 11 is less than the width at the jaws 3 and 4.

[0099] The jaws 3 and 4 each have a convex external surface and a substantially planar internal surface.

[0100] A resilient return member (not shown) is preferably provided to return the jaws 3 and 4 to the spaced-apart configuration, this resilient return member being, for example, a spring positioned around or in the vicinity of a pin of the articulation 8.

[0101] The handpiece 2 extends, for example, along a longitudinal axis X.

[0102] The jaw 3 extends, for example, along a longitudinal axis Yl.

[0103] The jaw 4 extends, for example, along a longitudinal axis Y2. A user interface, not shown in the figures, can be present on the device 1, in particular on the handpiece 2, in order to allow the user to control the operation of the device 1.

[0104] The device 1 in Figure 1 has a cord 17 designed to be able to supply the power necessary for operation of the device. The cord 17 may thus be a power cord designed to connect the device to the electricity network.

[0105] The cord 17 has an attachment 18 that can rotate relative to the handpiece.

[0106] The rotatable attachment 18 makes it possible to rotate the cord 17.

[0107] The handpiece 2 comprises an internal treatment member 14 for treating the hair to be treated on at least one of the two jaws 3 and 4 facing the other of the jaws.

[0108] The handpiece 2 may comprise a member, not shown, for detecting the configuration of the jaws 3 and 4, configured to detect whether the jaws 3 and 4 are in the closed configuration for treatment or the open configuration, in particular a Hall effect sensor.

[0109] Sensor

[0110] The handpiece comprises an inertial sensor 30 generating information on motion of the handpiece. The inertial sensor 30 may comprise a gyroscope, an accelerometer, or a housing comprising one or more gyroscopes and / or one or more accelerometers, in particular defining an inertial unit.

[0111] The inertial sensor 30 is arranged on the device at a distance C, measured between the centre of gravity of the inertial sensor 30 and the axis of rotation R, of less than 20% relative to the length L of the handpiece 2 along the longitudinal axis X and at a nonzero distance D along the longitudinal axis X from the nearest edge of the treatment member 14. In the example illustrated, the inertial sensor 30 is integrated in the cord 17 at the point where it is joined to the handpiece 2. However, it could be in the handpiece 2. Preferably, it is substantially at the proximal end of the handpiece.

[0112] The inertial sensor 30 may extend on the opposite side of the articulation 8 from the jaws. In a variant (not shown), it may be on the same side as the jaws.

[0113] The inertial sensor 30 may be integrated within the handpiece and in particular within the casing forming its outer surface.

[0114] The device may be configured so that the inertial sensor 30 generates handpiece motion information only when the jaws 3 and 4 are in the closed configuration. Operation of the inertial sensor 30 may be blocked when the jaws are in the open configuration, for example by cutting off the power supply or by any other suitable means.

[0115] The inertial sensor 30 may generate the motion information with respect to a reference frame comprising three axes that are fixed in space or movable with the handpiece, one of the axes notably being the longitudinal axis X and / or the axis of rotation R.

[0116] The motion information may be: a parameter relating to motion, in particular a movement of the handpiece from a first position to a second position, a motion in a direction of the handpiece, a speed of motion of the handpiece in at least one direction, a distance travelled by the handpiece and / or an acceleration or deceleration of the handpiece in at least one direction, and / or a parameter relating to a change of orientation of the handpiece, in particular rotation of the handpiece about at least one axis or an orientation of the handpiece in the fixed reference frame.

[0117] The parameter relating to motion, specifically the movement, speed and / or acceleration or deceleration, may be measured along an axis not parallel to the longitudinal axis of the handpiece, in particular along an axis perpendicular to the longitudinal axis of the handpiece, preferably parallel to a median plane extending between the jaws in the closed configuration of the jaws.

[0118] The parameter relating to a change of orientation, specifically the rotation or orientation, may be measured in the reference frame fixed in space, in particular in relation to the horizontal, or around a fixed axis of the handpiece, in particular an axis substantially parallel to the longitudinal axis of the handpiece, and in relation to a fixed reference axis in the fixed reference frame, in particular a horizontal or vertical axis.

[0119] The device 1 may comprise a processor (not shown), in particular a microcontroller.

[0120] The processor may determine coordinates of a position of the sensor of the handpiece in a reference system fixed in space, in particular a geodetic system, on the basis of the motion information and known reference location information. Alternatively or in addition, the processor may determine a distance to a known reference location. The inertial sensor 30 may be configured to generate the motion information continuously in real time, notably when its activation is triggered. Activation of the inertial sensor 30 may be triggered between two predetermined events.

[0121] The two predetermined events may be:

[0122] - the transition to the closed configuration of the jaws, signifying in particular the start of treatment of a lock of hair and / or positioning at the root of a lock of hair, and the transition to the open configuration of the jaws, signifying in particular the end of treatment and / or positioning of the device at the tip of a lock of hair,

[0123] - the transition to the closed configuration of the jaws, signifying in particular the start of treatment of a lock of hair and / or positioning at the root of a lock of hair, and the detection of contact of the two jaws with one another by a contact sensor positioned on the jaws, signifying in particular the absence of hair between the jaws and therefore positioning downstream of the tip of the lock of hair,

[0124] - the detection of the beginning of rotation of the handpiece about a fixed axis of the handpiece in one direction of rotation and the detection of the end of rotation of the handpiece about the fixed axis of the handpiece in said direction of rotation, and / or

[0125] - the detection of the start of movement of the handpiece in a predetermined direction, in particular by detecting a movement in one direction at a speed in that direction greater than a minimum reference speed, and the end of movement of the handpiece in the predetermined direction, in particular by detecting a change in direction of movement of the handpiece and / or a change in speed of the handpiece in said direction.

[0126] The processor may be configured to determine a distance of movement and / or an angle of rotation of the handpiece 2, defined as the rotation of the handpiece 2 about a fixed axis of the handpiece, for example the axis X, between two predetermined events, in particular from the above list, at least as a function of the motion information.

[0127] The processor may determine a length of a lock of hair, a position of the handpiece 2 along the lock of hair, a position of the handpiece on the hair, a change in orientation of the handpiece 2 along an axis parallel to the longitudinal axis X of the handpiece 2 or along another axis, or an orientation of the handpiece 2 along an axis parallel to the longitudinal axis X of the handpiece 2 or along another axis, a change in direction of use of the handpiece 2, a change in speed of the handpiece 2, the start of treatment or the end of treatment and / or the stopping of the handpiece 2 in the middle of treatment as a function of the motion information received.

[0128] The processor may determine whether the handpiece 2 is used in a first mode of use or in a second mode of use on the basis of the motion information, the first and second modes of use being different to one another.

[0129] The processor may determine the speed of movement of the handpiece 2 across the lock of hair in a direction, in particular a direction perpendicular to the longitudinal axis X, on the basis of the motion information.

[0130] The processor may include a speed, position and / or motion estimation algorithm for processing the motion information from the inertial sensor. The algorithm may include a Madgwick filter or a learning model.

[0131] The device may include a user warning member (not shown), in particular a screen on the handpiece casing or a screen remote from the handpiece, configured to receive the handpiece motion information and / or information generated by the processor on the basis of the motion information, in particular speed, position, rotation and / or distance to a reference point of the handpiece, and emit a user warning, in particular a signal perceptible to the user, notably an audible, visual or haptic signal as a function of the motion information.

[0132] Alternatively, as shown in Figure 2, the device 1 has no power supply cord and the handpiece 2 may comprise a power supply battery 35, in particular a removable and rechargeable battery. The inertial sensor 30 may be integrated in the casing of the handpiece 2 and may not be visible on the surface.

[0133] The invention is not limited to the examples that have been described above.

[0134] The method may comprise a step of applying a cosmetic product.

[0135] The handpiece may comprise external heating surfaces for curling by winding the hair around the handpiece and / or around one or both jaws.

Claims

Claims1. Device for treating the hair (1), in particular for curling and / or straightening the hair, with a movement of a handpiece (2) of the device along a lock of hair from a root to a tip, the handpiece (2) being elongate along a longitudinal axis (X), and comprising: two arms (5, 6) that are rotatable relative to one another about an axis of rotation (R) via an articulation (8) at one of their ends, each bearing a jaw for treating the hair (3, 4), the jaws (3, 4) being able to take up an open configuration for engaging the hair between them and a closed configuration for treatment, by moving the arms (5, 6) relative to one another, an inertial sensor (30) arranged along the longitudinal axis of the handpiece at a distance (C) from the axis of rotation (R) of less than 20%, better still less than 10%, even better still less than 5% relative to the length (L) of the handpiece (2) measured along the longitudinal axis (X) of the handpiece (2), the inertial sensor (30) being configured to generate information on motion of the handpiece (2).

2. Device according to Claim 1, wherein the jaws (3, 4) each have an internal treatment surface configured to face one another in the closed configuration of the jaws (3, 4), at least one of the jaws (3, 4) including at least one internal treatment member (14) defining the internal treatment surface configured to come into contact with or face a portion of the lock of hair during treatment.

3. Device according to Claim 2, wherein the inertial sensor (30) is at a nonzero distance (D) from the nearest edge of the internal treatment member (14) along the longitudinal axis (X).

4. Device according to any one of the preceding claims, wherein the inertial sensor (30) extends on the opposite side of the articulation (8) from the jaws (3, 4).

5. Device according to any one of the preceding claims, wherein the inertial sensor (30) is a gyroscope, an accelerometer or a housing comprising a combination of one or more gyroscopes and / or one or more accelerometers, in particular an inertial unit.

6. Device according to any one of the preceding claims, wherein the device (1) is configured so that the inertial sensor (30) generates handpiece (2) motion information only when the jaws (3, 4) are in the closed configuration, the device comprising a member fordetecting the configuration of the jaws, configured to detect whether the jaws are in the closed or open configuration, in particular a Hall effect sensor.

7. Device according to any one of the preceding claims, wherein the motion information is: a parameter relating to motion, in particular a movement of the handpiece from a first position to a second position, a motion in a given direction of the handpiece (2), a speed of motion of the handpiece (2) in at least one direction, a distance travelled by the handpiece (2) and / or an acceleration or deceleration of the handpiece (2) in at least one direction, and / or a parameter relating to a change of orientation of the handpiece (2), in particular rotation of the handpiece (2) about at least one axis or an orientation of the handpiece in the fixed reference frame.

8. Device according to any one of the preceding claims, wherein the inertial sensor (30) is configured to generate the motion information continuously in real time, notably when its activation is triggered, in particular between two predetermined events.

9. Device according to any one of the preceding claims, comprising a processor configured to determine a distance of movement and / or an angle of rotation of the handpiece (2), in particular about a fixed axis of the handpiece (2), between two predetermined events, at least as a function of the motion information.

10. Device according to any one of the preceding claims, comprising a processor configured to determine a length of a lock of hair, a position of the handpiece (2) along the lock of hair, a position of the handpiece (2) on the hair, a change in orientation of the handpiece (2) along an axis parallel to the longitudinal axis of the handpiece (2) or along another axis, or an orientation of the handpiece (2) along an axis parallel to the longitudinal axis of the handpiece or along another axis, a change in direction of use of the handpiece, a change in speed of the handpiece, the start of treatment or the end of treatment and / or the stopping of the handpiece in the middle of treatment as a function of the motion information received.

11. Device according to any one of the preceding claims, comprising a processor configured to determine the speed of movement of the handpiece (2) across the lock of hair on the basis of the motion information.

12. Device according to any one of the preceding claims, wherein the motion information is a parameter relating to motion measured along an axis not parallel to the longitudinal axis of the handpiece, the device comprising a processor for determining at least one piece of usage information as a function at least of the motion information, the processor being configured to determine whether the handpiece is used in a first mode of use or in a second mode of use on the basis of the motion information, the first and second modes of use being different to one another.

13. Device according to any one of the preceding claims, comprising a processor, in particular of microcontroller type, for determining at least one piece of usage information as a function at least of the motion information, the processor including a position estimation algorithm for processing the motion information from the inertial sensor.

14. Device according to any one of the preceding claims, wherein, in the closed configuration of the jaws, the handpiece is asymmetrical about at least one longitudinal median plane transverse to the internal treatment surface of at least one of the jaws.

15. Method for treating the hair, in particular straightening or curling the hair, by moving a handpiece (2) of a device (1) according to any one of the preceding claims, along a lock of hair.

Images