Classifications

• • A—HUMAN NECESSITIES
  • A45—HAND OR TRAVELLING ARTICLES
  • A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
  • A45D1/00—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor
  • A45D1/28—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor with means for controlling or indicating the temperature
• • A—HUMAN NECESSITIES
  • A45—HAND OR TRAVELLING ARTICLES
  • A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
  • A45D1/00—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor
  • A45D1/06—Curling-tongs, i.e. tongs for use when hot; Curling-irons, i.e. irons for use when hot; Accessories therefor with two or more jaws
• • A—HUMAN NECESSITIES
  • A45—HAND OR TRAVELLING ARTICLES
  • A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
  • A45D20/00—Hair drying devices; Accessories therefor
  • A45D20/04—Hot-air producers
  • A45D20/08—Hot-air producers heated electrically
  • A45D20/10—Hand-held drying devices, e.g. air douches
  • A45D20/12—Details thereof or accessories therefor, e.g. nozzles, stands
• • A—HUMAN NECESSITIES
  • A45—HAND OR TRAVELLING ARTICLES
  • A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
  • A45D7/00—Processes of waving, straightening or curling hair
• • A—HUMAN NECESSITIES
  • A45—HAND OR TRAVELLING ARTICLES
  • A45D—HAIRDRESSING OR SHAVING EQUIPMENT; EQUIPMENT FOR COSMETICS OR COSMETIC TREATMENTS, e.g. FOR MANICURING OR PEDICURING
  • A45D2200/00—Details not otherwise provided for in A45D
  • A45D2200/20—Additional enhancing means
  • A45D2200/207—Vibration, e.g. ultrasound

Definitions

• the invention relates to an ultrasound hair care device and method for drying and styling hair.
• hair styling as used herein is intended to encompass all actions such as hair crimping, curling, perming and straightening.
• US 2012/0291797 discloses a hair styling apparatus that includes a hair- heating device for applying heat to hair.
• the hair-heating device has a moisture-temperature setting and a dry-temperature setting less than moisture-temperature setting.
• a moisture sensor detects a moisture-indicating parameter of the hair, and generates a moisture-indicating signal indicative of whether the hair is at or below a predetemlined moisture threshold level.
• a control circuit adjusts the temperature of the hair-heating device from the moisture- temperature setting to the dry-temperature setting in response to the moisture sensor generating a moisture indicating signal indicative of the hair being at or below the
• the hair-heating device is active in the dry- temperature setting.
• US 2006/0272669 discloses hair styling appliances that utilize ultrasonic vibration for hair styling, and mentions that it is possible to atomize moisture inside hair to evaporate the moisture by ultrasonic vibration, even under room temperature. It is thus not necessary to use an extremely high temperature (e.g., 130° C) in order to evaporate moisture inside hair, which high temperature causes denaturation of protein and scald.
• an extremely high temperature e.g. 130° C
• the present invention is based on the new insight that nebulizing (the water for drying the hair) and styling with optimized but distinctively different ultrasound frequencies have significant benefits over using a single frequency range for both styling and drying with ultrasound. Moreover, styling can only be done in an optimal way when the hairs are dry.
• Both conventional and surface acoustic wave based ultrasound nebulization elements can be implemented in the haircare device.
• a first aspect of the invention provides an ultrasound hair care device for drying and styling hair.
• An ultrasound unit applies ultrasound to the hair.
• a hair moisture measurement unit measures a moisture level of the hair.
• a control unit controls the ultrasound unit based on the moisture level.
• ultrasound is applied to the hair at a first frequency not exceeding 1 MHz for drying the hair, and/or at a second frequency of at least 1 MHz for styling the hair in dependence on the moisture level.
• the first frequency does not exceed 0.5 MHz, and preferably does not exceed 0.4 MHz.
• the second frequency is advantageously at least 5 MHz, and preferably between 6.4 MHz and 500 MHz.
• An ultrasound intensity is advantageously at least 1 W/cm 2 , and preferably does not exceed 10 W/cm 2 .
• the control unit may comprise a look-up-table for switching the ultrasound unit to operate at the first frequency and/or at the second frequency in dependence on the moisture level.
• a second aspect of the invention provides a hair care method of drying and styling hair, the hair care method comprising measuring a hair moisture level; and applying ultrasound to the hair at a first frequency not exceeding 1 MHz for drying the hair and/or at a second frequency of at least 1 MHz for styling the hair in dependence of the hair moisture level.
• ultrasound is applied during a period not exceeding 2 minutes, and preferably not exceeding 1 minute.
• Fig. 1 shows a first embodiment of an ultrasound hair care device for drying and styling hair in accordance with the present invention.
• Fig. 2 schematically represents how the ultrasound frequencies for drying and styling can be applied over time.
• Fig. 3 illustrates ultrasound threshold intensities of the three identified main mechanisms involved in hair drying and styling as a function of ultrasound intensity.
• Fig. 4 shows a second embodiment of an ultrasound hair care device for drying and styling hair in accordance with the present invention.
• Fig. 1 shows an embodiment of an ultrasound hair care device 10 for drying hair and styling of hair.
• a first ultrasound generator 12 generates ultrasound at a frequency between 20 kHz to 0.4 MHz.
• a second ultrasound generator 14 generates ultrasound at a frequency between 6.4 MHz to 500 MHz.
• a first ultrasound transducer 16 in electrical communication with the first ultrasound generator 12 applies ultrasound to the water in hair lock 20 for nebulizing the water in hair lock as to dry hair.
• a second ultrasound transducer 18 in electrical communication with the second ultrasound generator 14 applies ultrasound to the hair lock 20 to style the hair.
• a hair moisture measurement unit 22 measures the moisture level of the hair lock 20.
• a control unit 24 controls a level of energy of the first ultrasound generator 12 and the second ultrasound generator 14 based on the measured hair moisture level as to provide optimum drying and styling to the hair.
• Nebulization by means of ultrasound can be achieved within a frequency range of 20 kHz - 1 MHz. To prevent cavitation, a frequency range of 20 kHz - 0.4 MHz is preferably selected. Styling by means of ultrasound can be achieved within a frequency range of 1 MHz - 500 MHz. To prevent cavitation, a frequency range of 6.4 MHz - 500 MHz could be selected. Finally, moisture sensing by means of ultrasound can be achieved within a frequency range of 100 kHz to 1 MHz. The preferred range of intensity of an effective ultrasound-based hair styling device is between 1 W/cm 2 and 10 W/cm 2 measured at the transducer-hair interface.
• Fig. 2 schematically represents how the ultrasound frequencies for drying D and styling S can be applied over time.
• Starting with wet hair initially relatively much ultrasound energy is applied at the ultrasound frequency for drying D, and relatively little ultrasound energy is applied at the ultrasound frequency for styling S.
• the amount of ultrasound energy applied at the ultrasound frequency for drying D becomes smaller, and the amount of ultrasound energy applied at the ultrasound frequency for styling S becomes larger.
• ultrasound styling and drying can be accomplished with different as well as overlapping frequency ranges.
• An average power limit of 10 W/cm 2 and application time was set to max 60 s to maintain practical relevance.
• Fig. 3 illustrates ultrasound threshold intensities of the three identified main mechanisms involved in hair drying and styling as a function of ultrasound intensity.
• the horizontal axis indicates frequencies in MHz, and the vertical axis indicates the threshold intensity in W/cm 2 .
• Curve A shows the threshold for styling through ultrasound heating (assuming all power is absorbed by hairs, 60 s).
• Curve B shows the threshold for styling through ultrasound heating (60% relative humidity, matched to experiments, 60 s).
• Curve C shows the threshold for nebulization (typical water film thickness), and curves CI - C2 show thresholds for nebulization (limits for 2-10 ⁇ water film thickness).
• Curve D shows the threshold for cavitation.
• Region 1 is a preferred region for ultrasound based styling (heating + cavitation).
• Region 2 is a preferred region for ultrasound based drying (nebulization).
• Region 3 is a preferred region for ultrasound based styling & drying.
• Region 4 is a preferred region for ultrasound based styling (heating).
• cavitation For cavitation to take place at least a thin film of liquid has to be present on the hairs.
• cavitation can play a role to enhance the drying process.
• Styling should preferably only take place once the hair has fully dried to prevent cavitation from happening.
• cavitation can damage the hair structure.
• two non-overlapping frequencies are preferred for several reasons:
• a combined ultrasound styling & drying effect requires a very narrow frequency range and a setup with little losses (Region 3).
• the threshold for styling through ultrasound heating will lie somewhere between the threshold as predicted by 100% absorption of ultrasound power in hairs (Curve A) and less efficient absorption of ultrasound power in hairs as found in experiments (Curve B), thus significantly shrinking the preferred region for ultrasound based styling & drying (Region 3).
• Variation in moisture content, relative humidity, hair density, hair diameter, volume etc. will all influence the preferred region for ultrasound based styling and drying, making it very hard to predict the right settings let alone to predetermine said parameters to fall in a viable frequency range for styling and drying.
• Fig. 4 shows a second embodiment of an ultrasound hair care device for drying and styling hair in accordance with the present invention.
• the main features of the ultrasound hair drying system of Fig. 4 include an ultrasound generator 100, an ultrasound amplifier 101, three ultrasound transducers 102 A, 102B, 102C (one for styling, one for drying, one for moisture sensing), a droplet handler 105, water film and droplets 103, 103 A, a control system 106, a user interface 107, and a thermal detector 108 to prevent overheating.
• the ultrasound generator 100 generates fixed or variable low- voltage ultrasound pulses, with frequency, voltage and pulse duration controlled by the control system 106 depending on treatment settings selected through the user interface 107 and the moisture content of the hairs detected by the ultrasound receiver 102C. This will enable atomization of liquid (103 A, 103B) from the hair surface 104. The resulting droplets will be removed or extracted by the droplet handler 105, which could be a simple air blower/extractor or something more complex.
• the hair care device can then be made to be safe for use if it is carefully designed such that:
• the transducer does not touch the skin/scalp
• a material with low acoustic impedance e.g. air
• a material with low acoustic impedance e.g. air
• the transducer does not emit ultrasound.
• Piezoelectric crystals are used to produce ultrasound (> 20 kHz).
• Non-piezoelectric techniques like Capacitance Micro -machined Ultrasonic Transducers (CMUT) can be used for higher frequencies (typically up to -100 MHz) and can be used with this invention. These techniques use relatively small transducers and are cheaper, thereby making it attractive for both home use and semi-professional hair care applications.
• CMUT Capacitance Micro -machined Ultrasonic Transducers
• CMUT transducers are used, a single ultrasound transducer may be used for both ultrasound frequencies. It is possible to have a hard switch between the different ultrasound frequencies in that below a certain moisture level the first frequency is produced while above that moisture level the second frequency is produced. It is alternatively possible to have a soft switch allowing for a gradual reduction of the intensity of the ultrasound produced at the first frequency, and a gradual increase of the intensity of the ultrasound produced at the second frequency, as a result of a decreasing moisture level of the hair. In such a soft switching embodiment, a look-up table is preferably used in the control unit for determining the intensities of the ultrasound produced at the first and second frequencies in dependence of the moisture level.
• any reference signs placed between parentheses shall not be construed as limiting the claim.
• the word “comprising” does not exclude the presence of elements or steps other than those listed in a claim.
• the word "a” or “an” preceding an element does not exclude the presence of a plurality of such elements.
• the invention may be implemented by means of hardware comprising several distinct elements, and/or by means of a suitably programmed processor. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

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• Cleaning And Drying Hair (AREA)
• Cosmetics (AREA)

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Citations (5)

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• 2016
  • 2016-02-17 EP EP16156168.3A patent/EP3207817A1/en not_active Withdrawn
• 2017
  • 2017-02-16 PL PL17704502T patent/PL3416521T3/pl unknown
  • 2017-02-16 ES ES17704502T patent/ES2792081T3/es active Active
  • 2017-02-16 CN CN201780011865.XA patent/CN108697217B/zh active Active
  • 2017-02-16 WO PCT/EP2017/053461 patent/WO2017140757A1/en active Application Filing
  • 2017-02-16 US US15/999,589 patent/US20210204667A1/en not_active Abandoned
  • 2017-02-16 EP EP17704502.8A patent/EP3416521B1/en active Active

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