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EP-4543336-B1 - A HAIR CUTTING DEVICE AND AN ATTACHMENT THEREFORE

EP4543336B1EP 4543336 B1EP4543336 B1EP 4543336B1EP-4543336-B1

Inventors

  • PALERO, Jonathan Alambra
  • VARGHESE, BABU
  • DOODEMAN, GERARDUS JOHANNES NICOLAAS
  • FRACKOWIAK, BRUNO JEAN FRANÇOIS
  • VISSER, CORNELIS GERARDUS
  • BOURQUIN, YANNYK PARULIAN JULIAN

Dates

Publication Date
20260506
Application Date
20230614

Claims (13)

  1. An attachment assembly (104, 1200) for an electric hair cutting device (100, 1100), the attachment assembly configured to be removably mounted to a body of the electric hair cutting device, the attachment assembly comprising: a plurality of electrodes (114) configured to contact the skin of a user during use; and a contact element (1106) electrically coupled to the plurality of electrodes, and configured such that, when the attachment assembly is mounted onto the body of the electric hair cutting device, the contact element is to receive radio frequency, RF. energy from an RF generator unit of the electric hair cutting device and to transmit the RF energy via the plurality of electrodes into the skin of the user in order to increase the temperature of the skin of the user; wherein the attachment assembly (104) is a comb attachment having teeth (106) that serve to lift hairs to be cut during use.
  2. An electric hair cutting device (100, 1100) comprising: a body (102) comprising: a radiofrequency, RF, generator unit (108) configured to generate RF energy; and a cutting assembly (1102) comprising: a cutting element (112); and a first plurality of electrodes (110) electrically coupled to the RF generator unit and being configured such that, when the first plurality of electrodes contact the skin of a user RF energy is conducted from the RF generator unit into the skin of the user in order to increase the temperature of the skin of the user; the electric hair cutting device (100, 1100) further comprising: an attachment assembly (104) as claimed in claim 1 removably mountable to the body, wherein the plurality of electrodes of the attachment assembly is a second plurality of electrodes (114) configured to contact the skin of a user during use; wherein the first plurality of electrodes are electrically coupled to the second plurality of electrodes of the attachment assembly such that, in use, RF energy can be conducted from the RF generator unit to the second plurality of electrodes and into the skin of the user in order to increase the temperature of the skin of the user.
  3. An electric hair cutting device (100) according to claim 2, wherein the RF generator unit (108) is configured to generate RF energy to be transmitted to the skin of the user such that a temperature of the skin of the user is caused to increase to a temperature of between 38°C and 42°C.
  4. An electric hair cutting device (100) according to claim 2 or claim 3, wherein the RF generator unit (108) is configured to operate according to at least one of the following parameters: i) an RF frequency of between 0.5 MHz and 100 MHz; ii) an RF peak-to-peak voltage of between 10 Vpp and 100 Vpp; and iii) a power rating of 20 W.
  5. An electric hair cutting device (100) according to any of the preceding claims, further comprising: a processing unit (118) in operative communication with the RF generator unit (108), the processing unit configured to: control an operating parameter of the RF generating unit; and control an operating parameter of the cutting element (112) of the electric hair cutting device.
  6. An electric hair cutting device (100) according to claim 5, further comprising: a skin impedance measurement unit (120) configured to measure an impedance of the skin between a pair of electrodes in the second plurality of electrodes (114) during use; wherein the processing unit (118) is configured to: control an operating parameter of the RF generator unit (108) based on the measured impedance of the skin.
  7. An electric hair cutting device (100) according to claim 6, wherein the second plurality of electrodes (114) comprise a first pair of electrodes of opposite polarity and a second pair of electrodes of opposite polarity; wherein the skin impedance measurement unit (120) is configured to measure an impedance of the skin between each electrode in the first pair of electrodes and between each electrode in the second pair of electrodes; and wherein the processing unit (118) is configured to: control a parameter of the RF energy delivered to each of the first and second pairs of electrodes based on the measured impedances of the skin.
  8. An electric hair cutting device (100) according to any of the preceding claims, wherein the relative positions of the electrodes of the first plurality of electrodes and/or the second plurality of electrodes are adjustable.
  9. An electric hair cutting device (100) according to any of the preceding claims, further comprising: at least one electrically insulating element (906) located between adjacent electrodes of opposite polarity of the second plurality of electrodes, the at least one electrically insulating element configured to contact the skin of the user during use in order to restrict the flow of current between the adjacent electrodes of opposite polarity via fluid present on the skin of the user.
  10. An electric hair cutting device (100) according to any of the preceding claims, wherein the second plurality of electrodes (114) comprise a first electrode of a first polarity, a second electrode of a second polarity and a third electrode of the second polarity; wherein the second electrode and the third electrode are located either side of the first electrode.
  11. An electric hair cutting device (100) according to claim 10, wherein a skin-contacting surface area of the first electrode is between two and four times greater than the skin-contacting surface area of each of the second electrode and the third electrode.
  12. An electric hair cutting device (100) according to claim 10 or claim 11, wherein the first electrode has a width of between 2.8 mm and 7 mm; wherein the second electrode has a width of between 1 mm and 3.5 mm; and wherein the third electrode has a width of between 1 mm and 3.5 mm.
  13. An electric hair cutting device (100) according to any of claims 10 to 12, wherein a separation between the first electrode and each of the second and third electrodes is between 3 mm and 15 mm.

Description

FIELD OF THE INVENTION The invention relates to a comb attachment for use with an electric hair cutting device and, more particularly, to an electric hair cutting device and an attachment which are capable of increasing a temperature of a user's skin. BACKGROUND OF THE INVENTION A hair cutting device, such as an electric shaver, a hair trimmer or clippers, may be used to cut or shave hair on part of a person's body, such as their head or face. An improved hair cutting experience can be achieved for the user of such a device by warming up the part of person's body where the hair is to be cut. One existing shaving device includes a component that heats up during use, and which transfers heat to the skin of the user. A downside of such direct heating methods is that the user can experience "hot spots" where the surface of the user's skin feels particularly hot in the region in contact with the shaving device, but little effect is experienced elsewhere. Furthermore, the heat from such direct heating is focussed at the skin surface, with little warming effect below the surface of the skin. A further problem to be overcome is to provide components capable of achieving the warming effect in a handheld device, where space is limited. There is therefore a desire for an alternative form of heating the skin of a user of a hair cutting device, which addresses the above-identified downsides. US 2012/233864 A1 discloses a skin-heating shaving apparatus including a source of RF energy. SUMMARY OF THE INVENTION The invention is defined by the appended independent claim. Further embodiments of the invention are illustrated in the dependent claims. SUMMARY OF THE DISCLOSURE There is a need for a hair cutting device that can provide warmth to a user during use safely, in order to provide an improved user experience. The inventors of the present disclosure have recognised that such a warming experience can be achieved by generating radiofrequency (RF) energy using an RF generator unit, and transmitting the RF energy via electrodes into the user's skin. The electrodes may be located on the hair cutting device itself, or on a comb attachment that can be mounted onto the hair cutting device. According to a first specific aspect, there is provided an electric hair cutting device comprising a body comprising a radiofrequency, RF, generator unit configured to generate RF energy; and a first plurality of electrodes electrically coupled to the RF generator unit; and an attachment assembly removably mountable to the body, the attachment assembly comprising: a second plurality of electrodes configured to contact the skin of a user during use. The electric hair cutting device further comprises a cutting element. The attachment assembly is a comb attachment having teeth that serve to lift hairs to be cut during use. The first plurality of electrodes are configured to be electrically coupled to the second plurality of electrodes of the attachment assembly when the attachment assembly is mounted to the body, such that RF energy generated by the RF generator unit is able to be transmitted to the skin of the user in order to increase the temperature of the skin of the user. In some embodiments, the RF generator unit may be configured to generate RF energy to be transmitted to the skin of the user such that a temperature of the skin of the user is caused to increase to a temperature of between 38°C and 42°C. The RF generator unit may be configured to operate according to at least one of the following parameters: i) an RF frequency of between 0.5 MHz and 100 MHz;ii) an RF peak-to-peak voltage of between 10 Vpp and 100 Vpp; andiii) a power rating of 20 W. The electric hair cutting device may, in some embodiments, further comprise a processing unit in operative communication with the RF generator unit, the processing unit configured to control an operating parameter of the RF generating unit; and control an operating parameter of a cutting element of the electric hair cutting device. In some embodiments, the electric hair cutting device may further comprise a skin impedance measurement unit configured to measure an impedance of the skin between a pair of electrodes in the second plurality of electrodes during use. The processing unit is configured to control an operating parameter of the RF generator unit based on the measured impedance of the skin. The second plurality of electrodes may comprise a first pair of electrodes of opposite polarity and a second pair of electrodes of opposite polarity. The skin impedance measurement unit may be configured to measure an impedance of the skin between each electrode in the first pair of electrodes and between each electrode in the second pair of electrodes. The processing unit may be configured to control a parameter of the RF energy delivered to each of the first and second pairs of electrodes based on the measured impedances of the skin. In some embodiments, the relative positions of the electrodes of t