Method and device for cosmetic treatment of keratin fibers

Abstract

Device (20) for hair treatment of at least one lock of hair to be treated comprising a member (26) for emitting at least one treatment agent included in the group comprising a light source with artificial electromagnetic radiation or a heat source.The hair treatment device (20) comprises: - a movement detection unit configured to detect a relative movement between the treatment device (20) and the lock of hair to be treated and comprising at least one photodetector (27) configured to perceive a brightness and generate at least one current value as a function of the perceived brightness; and - a signal processing unit (29) configured to read current values ​​transmitted by the photodetector (27) and deduce movement information therefrom as a function of a current variation; and an electronic control unit (ECU) configured to determine a control signal from the movement information to control the member (26) for emitting at least one treatment agent. Figure for the abstract: Fig 4.

Description

Title of the invention: Method and device for cosmetic treatment of keratin fibers

[0001] The present invention relates to the field of devices for treating keratin fibers, in particular the hair of a user.

[0002] More particularly, the invention relates to the cosmetic treatment of keratin fibers.

[0003] For the purposes of the present invention, the term “cosmetic product” means in particular a product as defined in Regulation (EC) No. 1223 / 2009 of the European Parliament and of the Council of 30 November 2009 relating to cosmetic products.

[0004] It is known to use hair shaping devices, in particular for straightening and / or smoothing operations.

[0005] Hair treatment devices are known comprising a heating member comprising a heating element with or without steam and which allows a lock of hair to be shaped.

[0006] We know hair treatment devices of the hair “brush” type.

[0007] The heating treatment surface may or may not be associated with the emission of steam.

[0008] Typically, such treatment devices include temperature sensors to prevent damage to the hair.

[0009] Reference may be made in this regard to document WO 2023 / 001980 - A1 which proposes a hair treatment device in the form of a brush, in particular having a heating and / or steam-diffusing treatment surface.

[0010] Furthermore, in order to allow lasting shaping of the hair, such brushes can be accompanied by the implementation of a treatment with a composition based on chemical active ingredients.

[0011] Such brushes may also include a heating member.

[0012] Document WO 2014 / 111646 - A1 is known, which proposes a styling device comprising an accelerometer configured to measure the movements of the styling operation. However, the sensitivity of the accelerometers is very low and requires rapid and significant movements and does not allow for the detection of quasi-constant movements.

[0013] It is also known to treat hair using electromagnetic rays. Reference may be made in particular to document FR 2 941 600 - A1 which proposes a method for treating hair in which the keratin fibers are exposed to infrared radiation.

[0014] However, in hair treatment devices using heat or electromagnetic radiation, the risks of burns or interaction with electromagnetic radiation are significant and it is necessary to be able to control exposure in time and / or power.

[0015] There is thus a need to improve the safety of hair treatment devices using heat or electromagnetic radiation.

[0016] Another object of the invention is to reduce the electrical consumption of the hair treatment device.

[0017] The subject of the invention is a device for treating at least one lock of hair to be treated, comprising a member for emitting at least one treatment agent included in the group comprising a light source with artificial electromagnetic radiation or a heat source.

[0018] The hair treatment device comprises: - a motion detection unit configured to detect relative movement between the treatment device and the lock of hair to be treated.

[0019] The detection unit comprises at least one photodetector configured to perceive a brightness and generate at least one current value, i.e. either a voltage or an intensity which depends on the resistivity in the case of a photoresistor, depending on the perceived brightness.

[0020] The detection unit further comprises a signal processing unit configured to record current values ​​transmitted by the photodetector and to deduce movement information therefrom as a function of a variation in said recorded current value.

[0021] The hair treatment device further comprises an electronic control unit configured to determine a control signal from the movement information to control the member for emitting the treatment agent(s).

[0022] More specifically, the signal processing unit is capable of determining whether the wick to be treated is moving relative to the treatment device when the wick is approached to the treatment device, in particular when the wick is placed inside the treatment device, in particular in the case of a clamp.

[0023] The device makes it possible to treat hair in a more controlled manner by limiting the untimely risks of external emission of heat or radiation outside the active treatment phase while limiting electrical consumption.

[0024] In known hair treatment devices comprising a conventional movement detector such as an accelerometer, the accelerometer is generally placed in the handle of the hair treatment device and therefore detects a movement of the handle without there necessarily being any movement of the lock of hair to be treated towards the device. Unlike known accelerometers, the photodetectors according to the invention make it possible to detect quasi-constant movements, or even the movements of the hair when the hair treatment device is static.

[0025] The heat source may be a thermal conductivity heating plate and / or a steam emission member.

[0026] Advantageously, the signal processing unit is configured to detect the contact of the lock of hair with the processing device when the variation in the current values ​​transmitted by the photodetector is greater than or equal to a threshold value.

[0027] Said threshold value is between 6nA per photodiode and 20mA per photodiode in the dark, lower values ​​being considered as relating to ambient nuisances.

[0028] A signal lower than 6nA is considered to be ambient nuisance.

[0029] The signal processing unit is thus configured to determine one or more current variations as a function of the current values ​​transmitted by the photodetector.

[0030] By “variation” of current, we mean a difference between a first current value at a time t outside the proximity of hair (initial t) and a second current value at a time t+1 or a series of current values ​​at times t+1, t+2, ..., t+n.

[0031] If the current variation is zero or almost zero between the single pair of values ​​or between each pair (t, ti) of current values ​​or between the first and last values ​​(t, tn), there is no movement detected between the lock of hair and the processing device. Conversely, if the current variation is not zero, and in particular greater than or equal to the threshold value, i.e. which cannot be confused with noise, a movement has been detected by the signal processing unit between the lock of hair and the processing device, therefore implying the presence of the lock in the device.

[0032] This is particularly the case when the treatment device is in the form of a clamp comprising two articulated arms, the bringing together of the arms generating the passage from a medium with ambient light to a medium confined only to the light of the treatment device.

[0033] Furthermore, in the case of a clip, without a lock of hair, the detected current or the resistivity value is constant. In other words, there is no variation in the light perceived by the photodetector.

[0034] It has been found that the movement of a lock of hair due to the natural irregularity of the fibers generates a variation in the light perceived by the photodetector during the movement of the lock. Thus, by processing the electrical signal from the photodetector, it is possible to deduce information on the movement relative to the hair treatment device and thus on the presence of the hair strand in the device.

[0035] The electronic control unit UCE is in particular configured to modify at least one treatment parameter, or even stop the member for emitting a treatment agent if no relative movement between the treatment device and the lock of hair to be treated has been detected.

[0036] By "treatment parameter" of the member for emitting a treatment agent, we mean the temperature and / or the light intensity as well as the flow rate when using a fluid treatment agent such as steam.

[0037] Preferably, the artificial electromagnetic radiation light source is configured to emit visible ultraviolet radiation, acronym UV-visible, infrared radiation, acronym IR, or microwaves.

[0038] For example, the artificial electromagnetic radiation light source comprises a plurality of light-emitting diodes, acronym LED, configured to emit monochromatic, visible ultraviolet radiation with a wavelength between 350nm and 750nm.

[0039] Preferably, the light-emitting diodes are directed radially towards the strand of hair.

[0040] Preferably, the photodetector is sensitive to UV-visible radiation.

[0041] The photodetector is then sensitive to variations in brightness in the visible ultraviolet radiation range.

[0042] For example, the heat source is configured to emit a temperature less than or equal to 210°C.

[0043] According to one embodiment, the photodetector is a photosensitive component.

[0044] For example, the photodetector is a photoresistor, called “Light Dependent Resistor”, acronym LDR, or “Photoresistor”) in Anglo-Saxon terms.

[0045] The photoresistor is an electronic component whose ohmic value varies according to the perceived brightness.

[0046] The higher the brightness, the lower its ohmic value (resistivity). Conversely, the lower the brightness, the higher its ohmic value (resistivity).

[0047] The photoresistor comprises, for example, a support, for example made of ceramic, and two pins, without polarity, for transmitting a current.

[0048] The surface of the photoresistor can be protected by an insulating resin or by conventional glass or glass filtering ultraviolet rays.

[0049] The photoresistor is an inexpensive component, very easy to implement and having very high sensitivity.

[0050] For example, the photodetector is a photodiode or a phototransistor.

[0051] Generally, the photodetector is configured to generate a current as a function of brightness.

[0052] According to a first embodiment, the hair treatment device is a hair brush.

[0053] By "brush" is meant a hair treatment device comprising a single arm carrying a plurality of teeth between which the hair is received as the brush passes over the hair. The brush may have a single row of teeth, and is then otherwise called a comb, or may have a plurality of rows of teeth. The brush may comprise a heated treatment surface. The teeth may also be actively heated or not.

[0054] The brush comprises a gripping portion and a treatment portion comprising a treatment surface and a plurality of teeth or projections arranged in a plurality of rows extending from the treatment surface, the member for emitting a treatment agent being disposed on the treatment surface.

[0055] In a variant of the invention, the detection unit comprises a plurality of photodetectors. This makes it possible to ensure that the lock of hair is detected even if it does not cover the entire treatment surface as the electromagnetic radiation light source.

[0056] The photodetectors may or may not be distributed uniformly over the brush head. For example, they may be distributed equidistant from each other.

[0057] For example, the member for emitting a treatment agent is integrated into the center of the head of said brush.

[0058] For example, the photodetector is arranged on one side of said device to perceive ambient light.

[0059] Advantageously, when the member for emitting an emitting agent of a treatment comprises, for example alone or in addition, a heat source, the treatment surface and / or the teeth can be heated by one or more heating elements powered electrically via an electric wire to the mains or to a base station, or by batteries.

[0060] According to one embodiment, the hair treatment device further comprises an additional light source located opposite the photodetector.

[0061] Indeed, when the treatment agent comprises a heat source, the device may comprise an additional light source configured to illuminate the photodetector.

[0062] This is not necessarily necessary when the member for emitting a treatment agent comprises a source of electromagnetic radiation which makes it possible both to treat the lock of hair and to illuminate the photodetector.

[0063] According to a second embodiment, the treatment device is an iron, and preferably a hair straightener.

[0064] By "hair straightener" is meant a hair treatment device comprising two arms articulated relative to each other around a hinge and forming a clamp movable between an open spaced position, advantageously in which a lock of hair to be treated can be arranged, and a closed configuration in which the lock of hair to be treated is in contact with the internal surfaces of said arms.

[0065] Alternatively, it could be provided that the treatment device comprises only one arm.

[0066] The two arms are preferably articulated relative to each other by a joint.

[0067] The arms preferably extend along respective longitudinal axes.

[0068] For example, the two arms each comprise a gripping portion on which the user can press to bring the two arms together in the closed position and a treatment portion located at the end of the corresponding arm and each comprising a treatment surface, said treatment surfaces facing each other.

[0069] A return member is preferably provided to exert a separation force between the arms without external stress from the user on said arms.

[0070] For example, the return member is a spring mounted around the articulation axis.

[0071] The treatment surfaces are, for example, in the form of a rectangular plate elongated along the respective longitudinal axes.

[0072] The movable arms define between them, with the treatment surfaces, a hair treatment zone intended to receive a lock of hair to be treated, along which the treatment device is moved, for example in the direction from the root to the tip of the hair.

[0073] The direction of movement of the treatment device is preferably substantially perpendicular to the arms.

[0074] The electromagnetic radiation light source is, for example, integrated on the treatment surface of one of the arms.

[0075] Advantageously, the photodetector(s) is (are) arranged on the same treatment surface as the electromagnetic radiation light source.

[0076] Preferably, the photodetector is arranged on a lateral edge of the treatment surface. Preferably, the photodetector is arranged on the treatment surface upstream of the light source in the direction of insertion and movement of the lock of hair.

[0077] According to one embodiment, the hair treatment device comprises an additional light source, integrated on the treatment surface of the other arm, in view of the photodetector. The additional light source can be in front of the photodetector, but not necessarily since it is sufficient that incident rays arrive on the photodetector.

[0078] The photodetector and the electromagnetic radiation light source are preferably integrated on two opposite treatment surfaces. In this case, it is no longer necessary to have the additional light source.

[0079] According to another embodiment, the member for emitting at least one treatment agent comprises a heat source and the device comprises an additional light source integrated on the treatment surface of the other arm, opposite the photodetector configured to illuminate the photodetector, the device comprising one or more heating elements in the form of heating resistors configured to heat one or more treatment surfaces, and powered electrically via an electric wire to the mains or to a base station, or by non-rechargeable primary or rechargeable secondary batteries.

[0080] In the case where the treatment agent comprises a heat source, at least one arm, and preferably each arm, is equipped with a treatment surface in the form of a heating plate. During the operations of treating a lock of hair, the latter is introduced between the two arms in the open position, then the two arms are manually closed on the lock of hair. The latter is then subjected, until the two arms open and the lock of hair is extracted, to the heat emitted by the heating element, the apparatus being able to be moved along the lock.

[0081] In a variant, the device may further comprise a water vapor emission member comprising a plurality of vapor outlets opening onto at least one treatment surface.

[0082] In this case, the device makes it possible to treat the hair while limiting the quantity of water used, which increases the autonomy of said device.

[0083] In another variant, the device may further comprise a member for emitting a cosmetic composition onto at least one treatment surface.

[0084] By shaping composition is meant a composition for curling, setting, straightening or smoothing hair.

[0085] The cosmetic compositions comprise, for example, one or more active agents chosen from reducing agents, and in particular thiols, oxidizing agents and in particular hydrogen peroxide or persalts, such as persulfates, coloring agents such as pigments, direct dyes or oxidation dyes, non-durable shaping agents such as styling polymers, preferably anionic, amphoteric or non-ionic, conditioning agents such as silicones, mineral or vegetable oils, vegetable waxes, surfactants cationic and cationic polymers, alkaline or acidic agents.

[0086] According to a second aspect, the invention relates to a method for hair treatment of at least one lock of hair to be treated comprising: - a step of verifying the operation of a hair treatment device for at least one lock of hair to be treated comprising: - an emitting member of at least one treatment agent included in the group comprising a light source with artificial electromagnetic radiation or a heat source, - a motion detection unit configured to detect a relative movement between the treatment device and the lock of hair to be treated and comprising at least one photodetector configured to perceive a brightness and generate at least one current value as a function of the perceived brightness and a signal processing unit configured to record the current values ​​transmitted by the photodetector and deduce therefrom movement information as a function of a variation of said recorded current value; and - an electronic control unit configured to determine a control signal from the movement information to control the emission member of a treatment agent.

[0087] The method comprises: - a step of lighting the emitting member of the treatment agent(s); - a step of reading the current values ​​generated by the photodetector and received by the signal processing unit, of deducing movement information as a function of a variation in said recorded current value and a control signal is determined from the movement information to control the emission member of the treatment agent(s); and - a step of comparing the variation of said current values ​​with a threshold value, considered for example as relative to ambient nuisances.

[0088] If the variation of the current values ​​is greater than or equal to the threshold value, that is to say that a movement has been detected by the signal processing unit between the lock of hair and the treatment device thus implying the presence of the lock in the treatment device, the emission member of the treatment agent(s) is triggered, for example either immediately or after a fixed latency time.

[0089] By “movement information”, we distinguish the static or moving position, i.e. the variation in current or resistivity.

[0090] If before treatment or at the end of treatment the variation of the current values ​​with respect to a time t without the presence of hair is less than the threshold value, that is to say that there is no detected presence of the lock of hair, we compare, during a step, the duration during which said variation of the current values ​​is less than the threshold value with a time threshold value, and if said duration is greater than or equal to said time threshold value, the emission member of a treatment agent is controlled during a step in order to prevent emission or to reduce its power to a safety value, or even to stop its power.

[0091] The variation in resistivity is linked to the variation in current transmitted by the photodetector to the signal processing unit. In other words, in the case where the photodetector is a photoresistor, if the variation in the resistivity values ​​of the photoresistor is less than the threshold value, i.e. zero or almost zero, plus or minus the sensitivity of the component, and this for the defined duration, the emitting member of a treatment agent is controlled by the electronic control unit in order to reduce or stop its power to ensure the safety of the user.

[0092] Alternatively, one could consider the quasi-zero slope received by the photodetectors in the case of a vacuum clamp, i.e. without wicks, analyze a group of current values ​​detected by the photodetector and received by the signal processing unit, and compare said group of values ​​with the quasi-zero slope. If this group of values ​​has a slope different from the quasi-zero slope, it is considered that there is movement information and there is then triggering of the processing device either immediately or after a fixed latency time.

[0093] The emission safety value, in particular electromagnetic, can be between 0.5 W / cm2 and 1.5 W / cm2 for components having a wavelength peak at 385nm.

[0094] The current threshold value is, for example, between 6nA and 20mA per photodiode, lower values ​​being considered as relating to ambient nuisances.

[0095] A signal lower than 6nA is considered to be ambient nuisance.

[0096] Indeed, if the variation of the current values ​​is greater than or equal to the value of threshold, therefore non-zero, this means that there has been movement between the lock of hair to be treated and the treatment device. Conversely, if the variation in current values ​​is lower than the threshold value, there has been no movement between the lock of hair to be treated and the treatment device.

[0097] The time threshold value is, for example, between 0.1s and 5s.

[0098] Preferably, if the variation of the time threshold values ​​at the end of processing is greater than or equal to the threshold value, the transmission of the processing is stopped.

[0099] If the duration is less than the time threshold value, the transmission of the treatment is maintained.

[0100] Operation can be done for example by connecting the device to the mains and / or by pressing a start switch present on the hair treatment device, for example on the gripping part, in particular for portable devices equipped with primary or secondary batteries.

[0101] The treatment method may further comprise, in a non-limiting manner, a step of applying a cosmetic composition, such as for example a composition for cleaning, coloring, bleaching, conditioning, repairing or shaping hair.

[0102] The present invention will be better understood upon studying the detailed description of embodiments, taken as non-limiting examples and illustrated by the appended drawings, in which:

[0103] [Fig.l] is a schematic perspective view of a hair treatment device according to one embodiment of the invention;

[0104] [Fig.2] represents the device of [Fig.l] from another perspective;

[0105] [Fig.3] is a front view of a treatment surface of the device of [Fig.l];

[0106] [Fig.4] is a schematic perspective view of a hair treatment device according to another embodiment of the invention; and

[0107] [Fig.5] represents a front view of the device of [Fig.5].

[0108] [Fig.6] represents the steps of the hair treatment method according to the invention using the treatment device of [Fig.l]; and

[0109] [Fig.7A], [Fig.7B], and [Fig.7C] illustrate examples of signal processing as a function of movement along the hair strand to be treated, time, and pitch of the hair strand to be treated.

[0110] A first example of a hair treatment device 10 is illustrated in Figures 1 to 3.

[0111] The treatment device here has the general shape of a clamp comprising two arms 11, 12 movable relative to each other between a spaced or open position in which a lock of hair to be treated can be arranged and a closed position in which the lock of hair to be treated is in contact with the internal surfaces 11a, 12a of said arms 11, 12.

[0112] The two arms 11, 12 are articulated relative to each other by an articulation 13 or hinge.

[0113] The arms 11, 12 extend along respective longitudinal axes X, Y.

[0114] The two arms 11, 12 each comprise a gripping portion 11b, 12b on which the user can press to bring the two arms together in the closed position.

[0115] A return member (not shown) is preferably provided to exert a separation force between the arms 11, 12 without external stress from the user on said arms.

[0116] For example, the return member is a spring mounted around the articulation axis 13.

[0117] Each arm 11, 12 comprises a processing part 11c, 12c located at the end of the corresponding arm opposite the joint 13.

[0118] Each treatment portion 11c, 12c comprises a treatment surface 14, 15. Said treatment surfaces 14, 15 face each other. In a variant, only one treatment surface could be provided.

[0119] Said treatment surfaces 14, 15 are here in the form of a rectangular plate elongated along the respective longitudinal axes X, Y.

[0120] The arms 11, 12 define between them, with the treatment surfaces 14, 15, a hair treatment zone intended to receive a lock of hair to be treated, along which the treatment device 10 is moved, for example in the direction going from the root to the tip of the hair.

[0121] The direction of movement of the treatment device 10 is preferably substantially perpendicular to the arms 11, 12.

[0122] The hair treatment device 10 comprises a member 18 for emitting at least one treatment agent comprising here a light source with artificial electromagnetic radiation.

[0123] As illustrated, the electromagnetic radiation light source 18 is integrated on the treatment surface 14 of one of the arms 11.

[0124] Alternatively, it could be provided that the light source 18 with electromagnetic radiation is integrated into the treatment surface 15 of the other of the arms 12.

[0125] As illustrated in [Fig.3], the hair treatment device 10 comprises a motion detection unit configured to detect relative movement between a treatment device 10 and the strand of hair to be treated.

[0126] The detection unit comprises at least one photodetector 17, here three photodetectors 17, configured to perceive a brightness and generate a current value.

[0127] More specifically, the photodetectors 17 are configured to generate a current characterized by either a voltage or an intensity which depends on the resistivity, depending on the perceived brightness.

[0128] The detection unit further comprises a signal processing unit 19 configured to read the current values ​​transmitted by the photodetector and in deduce movement information based on a current variation.

[0129] The signal processing unit 19 can thus determine whether the lock of hair to be treated is moving relative to the treatment device 10 or whether the treatment device 10 is moving relative to the lock of hair to be treated, i.e. when inserting the lock of hair into the treatment device 10.

[0130] By “movement information”, we distinguish between static or moving position, i.e. current variation.

[0131] As illustrated, and in no way limiting, the photodetectors 17 are integrated on the treatment surface 15 of one of the arms 12 and are distributed equidistant from each other.

[0132] As illustrated, and in a non-limiting manner, the photodetectors 17 and the light source 18 with electromagnetic radiation are integrated on two opposite treatment surfaces 14, 15. In other words, the photodetectors 17 are integrated on the treatment surface 15 opposite the light source 18 with electromagnetic radiation.

[0133] Alternatively, it could be provided that the photodetectors 17 are integrated on the same treatment surface as the electromagnetic radiation light source 18. In this case, the treatment device 10 could comprise an additional light source (not shown), integrated on the treatment surface 14 of the other arm 11, opposite the photodetectors 17.

[0134] Alternatively, it could be provided that the treatment member 18 comprises a heat source. In this case, the treatment device 10 comprises an additional light source integrated on the treatment surface 14 of the other arm 11, opposite the photodetectors 17 and configured to illuminate the photodetectors 17.

[0135] For example, the heat source is configured to emit a temperature between 90° and 250°C, preferably between 120° and 250°C.

[0136] This is not necessarily necessary when the treatment agent comprises a source of electromagnetic radiation which makes it possible both to treat the lock of hair and to illuminate the photodetector.

[0137] For example, the photodetectors 17 are, here, centered on the treatment surface 15.

[0138] In the case where the photodetectors 17 are integrated on the same surface as the light source 18, the photodetectors 17 can be integrated on a lateral edge of the treatment surface 15. In this case, the photodetector 17 is preferably integrated on the treatment surface 15 upstream of the light source 18 in the direction of insertion and movement of the lock of hair.

[0139] When the treatment agent comprises a heat source, the device 10 comprises one or more heating elements in the form of heating resistors configured to heat one or more treatment surfaces 14, 15 and powered electrically. electrically via an electric wire to the mains or to a base station, or by primary or secondary batteries.

[0140] The device 10 makes it possible to treat the hair in a controlled manner by limiting the untimely risks of external emission of heat or radiation while limiting electrical consumption.

[0141] The artificial electromagnetic radiation light source is configured to emit visible ultraviolet radiation, acronym UV-visible, infrared radiation, acronym IR, or microwaves.

[0142] The artificial electromagnetic radiation light source comprises, for example, a plurality of light-emitting diodes, acronym LED, configured to emit monochromatic, visible ultraviolet radiation with a wavelength ranging from 350nm to 750nm.

[0143] Preferably, the light-emitting diodes are directed radially towards the strand of hair.

[0144] Preferably, each photodetector is sensitive to UV-visible radiation.

[0145] The photodetector is sensitive to variations in brightness in the visible ultraviolet radiation range.

[0146] Each photodetector 17 is a photosensitive component.

[0147] For example, the photodetector 17 is a photoresistor, called “Light Dependent Resistor”, with the acronym LDR, or “Photoresistor” in English terms.

[0148] The photoresistor is an electronic component whose ohmic value varies according to the perceived brightness.

[0149] The higher the brightness, the lower its ohmic value (resistivity). Conversely, the lower the brightness, the higher its ohmic value (resistivity).

[0150] The photoresistor comprises, for example, a support, for example made of ceramic, and two pins, without polarity, for transmitting a current.

[0151] The surface of the photoresistor can be protected by an insulating resin or by conventional glass or glass filtering ultraviolet rays.

[0152] The photoresistor is an inexpensive component, very easy to implement and having very high sensitivity.

[0153] For example, the photodetector is a photodiode or a phototransistor.

[0154] Generally, the photodetector is configured to generate a current as a function of brightness.

[0155] The hair treatment device 10 further comprises an electronic control unit UCE configured to determine a control signal from the movement information to control the member 18 for emitting a treatment agent.

[0156] The signal processing unit 19 is configured to detect the contact of the lock of hair with the processing device when the variations in the current values ​​generated by the photodetector are greater than or equal to a threshold value.

[0157] The current threshold value is, for example, between 6nA and 20mA per photodiode in the dark, lower values ​​being considered as relating to ambient nuisances.

[0158] A signal lower than 6nA is considered to be ambient nuisance.

[0159] By “variation” of current, we mean a difference between a first value of current at a time t outside the proximity of hair (initial t) and a second current value at a time t+1 or a series of current values ​​at times t+1, t+2, ...; t+n.

[0160] If the current variation is zero or almost zero between the single pair of values ​​or between each pair (t, ti) of current values ​​or between the first and last values ​​(t, tn), there is no movement detected between the lock of hair and the treatment device. Conversely, if the current variation is not zero, and in particular greater than or equal to the threshold value, a movement has been detected by the signal processing unit between the lock of hair and the treatment device, therefore implying the presence of the lock in the device.

[0161] This is particularly the case when the treatment device is in the form of a clamp comprising two articulated arms, the bringing together of the arms generates the passage from a medium with ambient light to a medium confined only to the light of the treatment device.

[0162] Furthermore, in the case of a clip, without a lock of hair, the current generated is constant. In other words, there is no variation in the light perceived by the photodetector.

[0163] The electronic control unit UCE is in particular configured to modify at least one treatment parameter, or even stop the member 18 for emitting a treatment agent if no relative movement between the treatment device 10 and the lock of hair to be treated has been detected, i.e. in the event of the absence of the lock of hair in the treatment device 10.

[0164] The treatment device 10 may comprise a water vapor emission member comprising a plurality of vapor outlets (not shown) opening onto one or more treatment surfaces 14, 15. As a variant, the hair treatment device 10 comprises a single elongated vapor outlet.

[0165] The steam outlets are supplied with steam, for example, by a steam supply system (not shown).

[0166] The device allows hair to be treated while limiting the amount of water used, which reinforces the autonomy of said device.

[0167] The treatment device may further comprise a member (not shown) for emitting a cosmetic composition configured to emit a cosmetic composition onto one or both treatment surfaces 14, 15.

[0168] Figures 4 and 5 illustrate another embodiment in which the treatment device 20 is a hair brush.

[0169] As illustrated in Figures 4 and 5, the hair treatment device 20 comprises a gripping portion 21 and a treatment portion 22, called the “brush head”.

[0170] The treatment portion 22 may be in top view substantially rectangular in shape with rounded corners, as seen in [Fig.5], but it could be otherwise. The treatment portion 22 could be in top view substantially polygonal, oval or round in particular comprising a plurality of regularly spaced spikes on the treatment surface.

[0171] The treatment part 22 may have a substantially flat treatment surface 23. It is obviously possible to have a curved treatment surface 23, in particular convex towards the outside, for example substantially cylindrical with a closed or semi-cylindrical contour section.

[0172] The treatment part 22 here comprises a plurality of teeth or projections 22a arranged in a plurality of rows which extend from the treatment surface 23. The rows of teeth 22a extend along a main axis X2 of the brush 20. The teeth may be attached to the brush, being in particular made of a material different from that defining the treatment surface. The brush may comprise a single row of teeth, and it is then called a comb.

[0173] In a non-limiting manner, one or more teeth 22a may be made of heat-conducting material, for example iron, aluminum, titanium, stainless steel, graphite or ceramic, possibly provided with a coating.

[0174] The hair treatment device 20 comprises a member 26 for emitting a treatment agent comprising here a plurality of heating teeth 22a.

[0175] Alternatively, the member 26 for emitting a treatment agent may comprise a light source with artificial electromagnetic radiation close to the photodetectors 27. However, the brush already perceives ambient light, so that an additional light source is not essential.

[0176] As illustrated in [Fig.5], the hair treatment device 20 comprises a motion detection unit configured to detect relative motion between a treatment device 10 and the strand of hair to be treated.

[0177] The detection unit comprises at least one photodetector, here three photodetectors 27, configured to perceive a brightness and generate a current value.

[0178] More specifically, the photodetectors 27 are configured to generate a current, that is, either a voltage or an intensity which depends on the resistivity, depending on the perceived brightness.

[0179] The detection unit further comprises a signal processing unit 29 configured to record the current values ​​transmitted by the photodetector and to deduce movement information therefrom as a function of a current variation.

[0180] The signal processing unit 29 is here housed in the body of the hair treatment device 20, in particular at the level of the gripping part 21.

[0181] Each photodetector 27 is a photosensitive component.

[0182] For example, the photodetectors 27 are photoresistors, identical to those described in the embodiment with reference to FIGS. 1 to 3.

[0183] Alternatively, the photodetector 27 is a photodiode or a phototransistor.

[0184] Generally, the photodetector 27 is configured to generate a current as a function of the brightness.

[0185] The photodetectors 27 are arranged on one side of the brush 20 to perceive the ambient light.

[0186] The hair treatment device 20 comprises an electronic control unit UCE, here housed in the body of the hair treatment device 20, in particular at the level of the gripping part 21 configured to determine a control signal from the movement information to control the member 26 for emitting a treatment agent.

[0187] The electronic control unit UCE is notably configured to modify at least one treatment parameter, or even stop the member 26 for emitting a treatment agent if no presence of the lock of hair to be treated is detected.

[0188] The signal processing unit 29 is configured to detect the contact of the lock of hair with the processing device 20 when the variations in the current values ​​generated by the photodetector 27 are greater than or equal to a threshold value.

[0189] The current threshold value is, for example, between 6nA and 20mA per photodiode in the dark, lower values ​​being considered as relating to ambient nuisances.

[0190] A signal lower than 6nA is considered to be ambient nuisance.

[0191] By “variation” of current, we mean a difference between a first value of current at a time t outside the proximity of hair (initial t) and a second current value at a time t+1 or a series of current values ​​at times t+1, t+2, ..., t+n.

[0192] If the current variation is zero or almost zero between the single pair of values ​​or between each pair (t, ti) of current values ​​or between the first and last values ​​(t, tn), there is no movement detected between the lock of hair and the processing device. Conversely, if the current variation is not zero, and in particular greater than or equal to the threshold value, a movement has been detected by the signal processing unit 29 between the lock of hair and the processing device 20, therefore implying the presence of the lock in the device 20.

[0193] When the member 26 for emitting a treatment agent comprises a heat source, the treatment surface 23 and / or the teeth 22a can be heated by one or more heating elements (not shown) electrically powered via an electric wire to the mains or to a base station, or by primary or secondary batteries.

[0194] The heating elements may be, for example, one or more heating resistors.

[0195] Preferably, the treatment surface 23 and the teeth 22a are heated.

[0196] The hair treatment device 20 may comprise, in a non-limiting manner, a plurality of steam outlets (not shown) opening onto the treatment surface 23, and which may alternate with the teeth 22a of one of the rows of teeth, here the central row 20. As a variant, the hair treatment device 20 comprises a single elongated steam outlet.

[0197] The steam outlets are supplied with steam, for example, by a steam supply system (not shown).

[0198] As illustrated in [Fig.6], the hair treatment method 30 comprises a step 31 checking the operation of the hair treatment device 10.

[0199] Operation can be carried out for example by connecting the device to the mains and / or by pressing a start switch present on the hair treatment device 10, for example on the gripping part, in particular for portable devices equipped with primary or secondary batteries.

[0200] The hair treatment method 30 further comprises a step 35 during which current values ​​generated by the photodetectors 17, 27 and received by the signal processing unit 19, 29 are recorded, movement information is deduced therefrom as a function of a variation in said recorded current value and a control signal is determined from the movement information to control the member for emitting at least one treatment agent.

[0201] In step 36, the variation of said current values ​​is compared with a threshold value XXI, considered to be relative to ambient nuisances.

[0202] If the variation in the current values ​​is greater than or equal to the threshold value XXI, a movement has been detected by the signal processing unit between the lock of hair and the processing device, thus implying the presence of the lock in the device 10, and the emission member 18, 26 of the agent(s) is triggered in step 37. processing, either immediately or after a fixed latency time.

[0203] A preliminary step could be provided between step 35 and step 36 during which a current variation is determined.

[0204] Alternatively, one could consider the quasi-zero slope received by the photodetectors in the case of a vacuum clamp, i.e. without wicks, analyze a group of current values ​​detected by the photodetector and received by the signal processing unit, and compare said group of values ​​with the quasi-zero slope. If this group of values ​​has a slope different from the quasi-zero slope, it is considered that there is movement information and, in step 37, the emission member 18, 26 of the treatment agent(s) is triggered, either immediately or after a fixed latency time.

[0205] By “variation” of current, we mean a difference between a first current value at a time t outside the proximity of hair (initial t) and a second current value at a time t+1 or a series of current values ​​at times t+1, t+2, ..., t+n.

[0206] If, before treatment or at the end of treatment, the variation in the current values ​​relative to a time t without the presence of hair is less than the threshold value XXI, i.e. there is no detected presence of the lock of hair, the duration during which said variation in the current values ​​is less than the threshold value XXI is compared, in step 38, with a time threshold value XX2.

[0207] If the duration is greater than or equal to said time threshold value XX2, the electronic control unit UCE controls, in step 39, the emission member 18, 26 of a treatment agent in order to prevent the emission or to reduce its light power to a safety value in the case where the treatment agent is an electromagnetic light source, or even to stop its light power. In other words, the emission of the treatment is stopped.

[0208] If the duration is less than the time threshold value XX2, the emission member 18, 26 of a treatment agent is kept switched on in step 40. In other words, the emission of the treatment is maintained.

[0209] The current threshold value XXI is, for example, between 6nA and 20mA per photodiode, lower values ​​being considered as relating to ambient nuisances.

[0210] A signal lower than 6nA is considered to be ambient nuisance.

[0211] The time threshold value XX2 is, for example, between 0.1 s and 5 s.

[0212] The treatment method 30 may further comprise, in a non-limiting manner, a step of applying a cosmetic composition, such as for example a composition for cleaning, coloring, bleaching, conditioning, repairing or shaping hair.

[0213] Figures 7A to 7C illustrate examples of signal processing as a function of the displacement, on the ordinate, along the strand of hair to be treated, of the time, on the abscise, and of the pitch of the strand of hair to be treated.

[0214] The tone height of a hair is defined by HTn with n ranging from 1 to 10, 1 being the lightest and 10 the darkest.

[0215] [Fig.7A] corresponds to a tone height of HT9, that is to say a black hair.

[0216] [Fig.7B] corresponds to a tone height of HT4, that is to say a chestnut-colored hair.

[0217] [Fig.7A] corresponds to a tone height HT1, that is to say a blond colored hair.

[0218] It is observed that the photodetectors receive different levels of brightness when moving along the strand of hair and that the generated current signal forms an oscillation.

[0219] The perception of brightness by the photodetector is clearer in the case of dark hair greater than a tone height HT4. The invention is not limited to a hair treatment device in the form of a brush or a clip.

[0220] Indeed, it could be provided that the treatment device 10 comprises only one arm 11.

[0221] It could also be provided that the treatment device has another shape.

[0222] The hair treatment device 10, 20 may comprise a user interface (not shown) allowing the user to enter various input data, in particular a brightness of the electromagnetic light source, an operating temperature, a steam flow rate, a characteristic of the hair, or to deactivate one or more functions of the hair treatment device 10, 20, in particular the application of steam or the application of heat. It may also allow the hair treatment device 10, 20 to transmit information to the user, in particular the temperature of the treatment surface or the teeth in the case of a brush, the end of heating of the vaporization chamber and / or the treatment surface and / or the teeth.

[0223] Unlike conventional motion detectors such as accelerometers, the detection unit according to the invention makes it possible to detect quasi-constant movements, or even the movements of the hair when the device is static. Thanks to the treatment device according to the invention, the hair can be treated in a controlled manner by limiting the untimely risks of external emission of heat or radiation while limiting the electrical consumption.

Claims

Claims

1. Device (10, 20) for hair treatment of at least one lock of hair to be treated comprising a member (18, 26) for emitting at least one treatment agent included in the group comprising a light source with artificial electromagnetic radiation or a heat source, characterized in that the hair treatment device (10, 20) comprises: - a motion detection unit configured to detect a relative movement between the treatment device (10, 20) and the lock of hair to be treated and comprising at least one photodetector (17, 27) configured to perceive a brightness and generate at least one current value as a function of the perceived brightness; and - a signal processing unit (19, 29) configured to record current values ​​transmitted by the photodetector (17, 27) and deduce therefrom movement information as a function of a variation of said recorded current value;and - an electronic control unit (ECU) configured to determine a control signal from the movement information to control the member (18, 26) for emitting the treatment agent(s);

2. Hair treatment device (10, 20) according to claim 1, wherein the signal processing unit (19, 29) is configured to detect the contacting of the lock of hair with the treatment device (10, 20) when the variation of the current values ​​transmitted by the photodetector (17, 27) is greater than or equal to a threshold value.

3. A hair treatment device (10, 20) according to claim 1 or 2, wherein the artificial electromagnetic radiation light source is configured to emit visible ultraviolet radiation, infrared radiation, or microwaves.

4. Hair treatment device (10, 20) according to claim 3, wherein the artificial electromagnetic radiation light source comprises a plurality of light-emitting diodes, acronym LED, configured to emit monochromatic, visible ultraviolet radiation with a wavelength between 350nm and 750nm.

5. Hair treatment device (10, 20) according to any one of the preceding claims, wherein the photodetector (17, 27) is a photosensitive component, preferably a photoresistor or a photodiode or a phototransistor.

6. A hair treatment device (20) according to any preceding claim, wherein said device (20) is a hair brush comprising a gripping portion (21) and a treatment portion (22) comprising a treatment surface (23) and a plurality of teeth (22a) arranged in a plurality of rows extending from the treatment surface (23), and wherein the treatment agent emitting member (26) is disposed on the treatment surface (23).

7. A hair treatment device (20) according to claim 6, wherein the photodetector (27) is disposed on one side of said device (20) for sensing ambient light.

8. A hair treatment device (20) according to claim 6 or 7, wherein when the member (26) for emitting at least one emitting agent of a treatment comprises a heat source, the treatment surface (23) and / or the teeth (22a) can be heated by one or more heating elements.

9. Hair treatment device (10) according to any one of claims 1 to 5, further comprising an additional light source located opposite the photodetector (17).

10. Hair treatment device (10) according to any one of claims 1 to 5 or 9, wherein the treatment device (10) has the general shape of a clamp comprising two arms (11, 12) movable relative to each other between a spaced apart position and a closed position in which the lock of hair to be treated is in contact with the internal surfaces (11a, 12a) of said arms (11, 12).

11. A hair treatment device (10) according to claim 10, wherein the two arms (11, 12) each comprise a gripping portion (11b, 12b) on which the user can press to bring the two arms together in the closed position and a treatment portion (11e, 12c) located at the end of the corresponding arm and each comprising a treatment surface (14, 15), said treatment surfaces (14, 15) facing each other.

12. Hair treatment device (10) according to claim 11, in which the member for emitting at least one treatment agent comprises a source of electromagnetic radiation and in which said source light (18) with electromagnetic radiation is integrated on the treatment surface (15) of one of the arms (12).

13. Hair treatment device (10) according to claim 11 or 12, wherein the photodetector (17) is integrated on the same treatment surface (15) as the electromagnetic radiation light source (18), and preferably, the photodetector (17) is integrated on a lateral edge of the treatment surface (15) and / or the photodetector (17) is integrated on the treatment surface (15) upstream of the light source (18) in the direction of insertion and movement of the lock of hair.

14. Hair treatment device (10) according to claim 12, comprising an additional light source (18), integrated on the treatment surface (14) of the other arm (11), opposite the photodetector (17).

15. Hair treatment device (10) according to claim 12, in which the photodetector (17) and the electromagnetic radiation light source (18) are integrated on two opposite treatment surfaces (14, 15).

16. A hair treatment device (10, 20) according to claim 6 or 11, taken in combination with any one of the preceding claims, comprising a water vapor emitting member comprising a plurality of vapor outlets opening onto at least one treatment surface (14, 15, 23).

17. Hair treatment device (10, 20) according to claim 6 or 11, taken in combination with any one of the preceding claims, comprising a member for emitting a cosmetic composition onto at least one treatment surface (14, 15, 23).

18. Method (30) for hair treatment of at least one lock of hair to be treated comprising: - a step (31) of verifying the operation of a hair treatment device (10, 20) of at least one lock of hair to be treated comprising a member (18, 26) for emitting at least one treatment agent included in the group comprising a light source with artificial electromagnetic radiation or a heat source, a movement detection unit configured to detect a relative movement between the treatment device (10, 20) and the lock of hair to be treated; and comprising at least one photodetector (17, 27) configured to perceive a brightness and generate at least one light source (18, 26) for detecting ... at least one current value as a function of the perceived brightness and a signal processing unit (19, 29) configured to record current values ​​transmitted by the photodetector (17, 27) and deduce movement information therefrom as a function of a variation in said recorded current value; and an electronic control unit (ECU) configured to determine a control signal from the movement information to control the member (18, 26) for emitting the treatment agent(s), the method (30) comprising: - a step (33) of lighting the member (18, 26) for emitting the treatment agent(s); - a step (35) of reading the current values ​​generated by the photodetector (17, 27) and received by said signal processing unit (19, 29), of deducing movement information as a function of a variation in said recorded current value and a control signal is determined from the movement information to control the member (18, 26) for emitting the treatment agent(s); - a step (36) of comparing the variation of said current values ​​with a threshold value (XXI), - if the variation in the current values ​​is greater than or equal to the threshold value (XXI), the member (18, 26) for emitting the treatment agent(s) is triggered, - if, before treatment or at the end of treatment, the variation in the current values ​​relative to a time (t) without the presence of hair is less than the threshold value (XXI), the duration during which said variation in the current values ​​is less than the threshold value (XXI) is compared, during a step (38), with a time threshold value (XX2), and - if said duration is greater than or equal to the time threshold value (XX2), the device (18, 26) for emitting the treatment agent(s) is controlled during a step (39) in order to stop or reduce its power to a safety value.

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