Hair drying and / or styling apparatus and method
The integration of a multi-layer heater with independently powered electrodes and a dielectric layer in hair devices addresses the issue of inconsistent heating, achieving uniform temperature distribution and improved hair treatment results.
Patent Information
- Authority / Receiving Office
- HK · HK
- Patent Type
- Applications
- Current Assignee / Owner
- JEMELLA LTD
- Filing Date
- 2026-05-18
- Publication Date
- 2026-07-10
AI Technical Summary
Existing hair drying and styling devices lack efficient and uniform heating mechanisms, leading to inconsistent temperature distribution and suboptimal hair treatment outcomes.
A multi-layer heater with independently powered heating electrodes and an upper dielectric layer for electrical isolation is integrated into the device, allowing for precise temperature control and uniform heating zones along the hair contact surface.
The solution provides consistent and uniform heating, enhancing hair treatment efficacy and improving user experience by ensuring even temperature distribution.
Smart Images
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Abstract
Description
A hair drying and / or styling device is provided. The device includes a multi-layer heater having multiple functional layers interlocked together, wherein the multi-layer heater is installed within the device so that during use by a user, hair comes into contact with the hair contact surface of the multi-layer heater and is heated by conductive heating. The multi-layer heater may include a heating electrode layer comprising multiple independently powered heating electrodes formed of a conductive material that generates heat when an electric current passes through the heating electrodes. In this configuration, the multiple heating electrodes may be arranged sequentially along the length of the multi-layer heater and define corresponding multiple heating zones arranged along the length of the hair contact surface of the multi-layer heater. At least one upper dielectric layer is disposed above the heating electrode layer for electrical isolation of the heating electrode layer. The number of heating zones per centimeter of length of the multi-layer heater is preferably between 0.6 and 2.5.
Claims
Claims1. A hair drying and / or styling appliance comprising a multilayer heater having a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating, wherein the multilayer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a conductive material that generates heat when a current is passed through the one or more heater electrodes; and at least one upper dielectric layer over the heater electrode layer to electrically insulate the heater electrode layer; wherein an upper surface of the dielectric layer provides the hair contacting surface of the multi-layer heater.
2. The appliance according to claim 1 , wherein the at least one dielectric layer is formed as a coating on an upper surface of the heater electrode layer.
3. The appliance according to claim 2, wherein the coating is applied as a spray, a wash, physical vapour deposition, sputtering or evaporation.
4. The appliance according to any of claims 1 to 3, wherein the heater has a power density that is greater than 2 W / cm2and less than 100 W / cm2, preferably greater than 8 W / cm2.
5. The appliance according to any of claims 1 to 4, wherein the dielectric layer is mounted directly on to an upper surface of the heater electrode layer.
6. The appliance according to any of claims 1 to 5, wherein one or more of the heater electrodes are formed of a conductive material whose resistance varies with the temperature of the heater, whereby the temperature of the hair contracting surface can be determined by measuring the resistance of the one or more heater electrodes.
7. The appliance according to any of claims 1 to 6, wherein the heater electrode layer comprises a plurality of independently controllable heater electrodes that define a corresponding plurality of heating zones on the hair contacting surface of the multilayer heater.
8. The appliance according to claim 7, wherein the plurality of independently controllable heater electrodes are arranged in a two dimensional array along the length and width of the heater.
9. The appliance according to claim 8, wherein the plurality of independently controllable heater electrodes are arranged in two rows extending along the length of the heater.
10. The appliance according to any of claims 7 to 9, wherein the multilayer heater further comprises at least one heat spreading layer provided under the heater electrode layer.11 . The appliance according to claim 10, wherein a second dielectric layer is provided between the heater electrode layer and the heat spreading layer.
12. The appliance according to claim 10or 11 , wherein the heat spreading layer comprises a plurality of heat spreaders that regularise the heating provided within the heating zones.
13. The appliance according to claim 12 when dependent on claim 9, wherein one heat spreader is provided for each row of independently controllable heater electrodes.
14. The appliance according to claim 12, wherein at least one heat spreader is provided for each heater electrode.
15. The appliance according to any of claims 12 to 14, wherein each heat spreader is formed as an island that does not touch neighbouring heat spreaders to minimise heat spreading from one heating zone to an adjacent heating zone.
16. The appliance according to any of claims 12 to 15, wherein each heat spreader is formed of a metal.
17. The appliance according to any of claims 12 to 16, wherein the heat spreaders are separated from each other in the plane perpendicular to the thickness by a solid or semisolid material, whose thermal conductivity is lower than 35 W / m.K and preferably lower than 0.3 W / m.K.
18. The appliance according to any preceding claim, wherein the multilayer heater further comprises an auxiliary heater electrode layer comprising one or more heater electrodes provided below the heater electrode layer and a dielectric layer provided between the heater electrode layer and the auxiliary heater electrode layer.
19. The appliance according to any of claims 1 to 18, wherein the multilayer heater is flexible and is bonded to a rigid structure to provide the multilayer heater with rigidity.
20. The appliance according to any of claims 1 to 19, wherein the multilayer heater has a flat, curved and / or ribbed heating surface.
21. The appliance according to any of claims 1 to 20, wherein the multilayer heater provides a flat heating surface and has curved edges that provide a curved heating surface.
22. The appliance according to any of claims 1 to 21 , further comprising a controller configured to control the application of power to the multilayer heater to control the heat produced by the multilayer heater.
23. The appliance according to any of claims 1 to 22, wherein the appliance is a one arm or a two arm device comprising a handle.
24. The appliance according to any preceding claim, wherein the multilayer heater is flexible and is mounted to a rigid support, wherein terminals of the one or more heater electrodes are provided on at least one connection tab that folds under the rigid support.
25. The appliance according to claim 24, wherein a rigid circuit board is provided under the rigid support and wherein a plurality of spring fingers are provided for making an electrical connection between terminals on the rigid circuit board and the terminals of the one or more heater electrodes provided on said connection tabs.
26. The appliance according to any of claims 1 to 25, wherein the upper dielectric layer has a dielectric breakdown strength greater than 500 volts and a thermal impedance between 9.35 x 10'4KW1cm2and 0.8 KW1cm2.
27. A method of making a hair drying and / or styling appliance, the method comprising: providing a multilayer heater having a plurality of functional layers that are bonded together; mounting the multilayer heater in the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating; wherein providing the multilayer heater includes: providing a heater electrode layer comprising one or more heater electrodes formed of a conductive material that generates heat when a current is passed through the one or more heater electrodes; and providing at least one upper dielectric layer over the heater electrode layer to electrically isolate the heater electrode layer from the hair contacting surface; wherein an upper surface of the dielectric layer provides the hair contacting surface of the multi-layer heater.
28. A hair drying and / or styling appliance comprising a multilayer heater having a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating, wherein the multilayer heater includes: a heater electrode layer comprising a plurality of independently powerable heater electrodes formed of an electrically conductive material that generates heatwhen a current is passed through them, wherein the plurality of heater electrodes are arranged sequentially along a length of the multilayer heater and define a corresponding plurality of heating zones arranged along the length of the hair contacting surface of the multilayer heater; and at least one upper dielectric layer over the heater electrode layer to electrically isolate the heater electrode layer; and wherein the number of heating zones per centimetre of length of the multilayer heater is between 0.6 and 2.5.
29. The appliance according to any of claim 28, wherein the upper dielectric layer has a dielectric breakdown strength greater than 500 volts and a thermal impedance between 9.35 x 10’4KW1cm2and 0.8 KW1cm2.
30. The appliance according to claim 28 or 29, wherein the multilayer heater has a thickness, as measured across all of the plurality of layers of the multilayer heater, which is between 75pm and 300pm.
31. The appliance according to any of claims 28 to 30, wherein an average thermal conductivity of the layers forming the multilayer heater is less than 300 W / m.K and greater than 80 W / m.K.
32. The appliance according to claim 31 , wherein the average thermal conductivity is averaged through the thickness of the multilayer heater.
33. The appliance according to any of claims 28 to 32, wherein the heater electrodes are configured to provide a power density of between 4 WcnT2and 25 Wcm'2to heat hair passing over the hair contacting surface.
34. The appliance according to any of claims 28 to 33, wherein the maximum permitted temperature of a heating zone is less than 250°C.
35. The appliance according to any of claims 28 to 34, wherein the multilayer heater further comprises an auxiliary heater electrode layer comprising one or more heater electrodes provided below the heater electrode layer and a dielectric layer provided between the heater electrode layer and the auxiliary heater electrode layer.
36. A method of making a hair drying and / or styling appliance, the method comprising: providing a multilayer heater having a plurality of functional layers that are bonded together; mounting the multilayer heater in the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating; wherein providing the multilayer heater includes: providing a heater electrode layer comprising a plurality of independently powerable heater electrodes formed of a conductive material that generates heat when a current is passed through them, wherein the plurality of heater electrodesare arranged sequentially along a length of the multilayer heater and define a corresponding plurality of heating zones arranged along the length of the hair contacting surface of the multilayer heater; and providing at least one upper dielectric layer over the heater electrode layer to electrically isolate the heater electrode layer; and wherein the number of heating zones per centimetre of length of the multilayer heater is between 0.6 and 2.5.
37. A multilayer heater for use in a hair drying and / or styling appliance, the multilayer heater having a plurality of functional layers that are bonded together, wherein the multilayer heater provides a hair contacting surface to heat hair that comes into contact with the multilayer heater, wherein the multilayer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a first conductive material that generates heat when a current is passed through the one or more heater electrodes; a heat spreading layer comprising one or more heat spreaders, each heat spreader being formed of a second conductive material that is different to the first conductive material; and at least one dielectric layer sandwiched between the heater electrode layer and the heat spreading layer.
38. The multilayer heater according to claim 37, wherein the heater electrode layer comprises a plurality of independently powerable heater electrodes formed of an electrically conductive material that generates heat when a current is passed through them, wherein the plurality of heater electrodes are arranged sequentially along a length of the multilayer heater and define a corresponding plurality of heating zones arranged along the length of the hair contacting surface of the multilayer heater.
39. The multilayer heater according to claim 38, wherein the heat spreader layer comprises a plurality of heat spreaders.
40. The multilayer heater according to any of claims 37 to 39, wherein the multilayer heater has a thickness, as measured across all of the plurality of layers of the multilayer heater, which is between 30pm and 2mm and preferably between 75pm and 300pm.
41. The multilayer heater according to any of claims 37 to 40, wherein the first conductive material comprises steel and the second conductive material comprises copper.
42. The multilayer heater according to any of claims 37 to 41 , comprising an upper dielectric layer provided on a surface of the heater electrode layer and having a dielectric breakdown strength greater than 500 volts and a thermal impedance between 9.35 x 10'4KW1cm2and 0.8 KW1cm2.
43. A hair drying and / or styling appliance comprising a multilayer heater having a plurality of functional layers that are bonded together, wherein the multilayer heater is mounted within the appliance so that during use of the appliance by a user, hair contacts a hair contacting surface of the multilayer heater and is heated by conductive heating, wherein the multilayer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a conductive material that generates heat when a current is passed through the one or more heater electrodes; at least one upper dielectric layer over the heater electrode layer to electrically insulate the heater electrode layer; wherein the heater is supported within a housing of the appliance by a rigid support; wherein terminals of the one or more heater electrodes are provided on connection tabs that fold under the rigid support, wherein a rigid circuit board is provided under the rigid support that carries drive and control circuitry for controlling the heating of the multilayer heater, and wherein a plurality of spring fingers are provided for making an electrical connection between terminals on the rigid circuit board and the terminals of the one or more heater electrodes provided on said connection tabs.