Hair drying and / or styling device and method

Abstract

A hair drying and / or styling device is provided. The device includes a multi-layer heater having a plurality of functional layers bonded together, wherein the multi-layer heater is mounted within the device such that, during use of the device by a user, hair contacts a hair contact surface of the multi-layer heater and is heated by conductive heating. The multi-layer heater can include a heater electrode layer including a plurality of independently powerable heater electrodes formed of an electrically conductive material that generate heat when an electrical current is passed through the plurality of heater electrodes. In this case, the plurality of heater electrodes can be arranged sequentially along a length of the multi-layer heater and define a corresponding plurality of heating zones arranged along a length of the hair contact surface of the multi-layer heater. At least one upper dielectric layer is disposed over the heater electrode layer to electrically isolate the heater electrode layer. The number of heating zones per centimeter length of the multi-layer heater is preferably between 0.6 and 2.5.

Description

Technical Field

[0001] This invention relates to heating devices and methods, as well as components and systems thereof. The heater can be used for styling hair. For example, such hair styling can be done by a user with their own hair or by a hairstylist. The invention particularly, but not exclusively, relates to a hair drying and / or styling appliance or apparatus comprising at least one heater having multiple independently controllable heating zones. Background Technology

[0002] Heated hair styling tools use heat to raise the temperature of hair to the desired styling temperature. For example, a straightener with a heating plate applies heat directly to hair, whether wet or dry, through conduction, achieving the desired temperature for styling. The hair can be heated to temperatures particularly suitable for styling (e.g., heated to or above the hair's glass transition stage temperature). At lower temperatures, the user may have to make many passes through the hair with the straightener to achieve the desired styling effect, while at higher temperatures, there is a risk of permanent damage to the hair.

[0003] Similarly, heated brushes or hair dryers can be used to style hair by heating air, which in turn heats the hair to a suitable temperature for styling. Hair is usually styled while wet, such as after the user has washed it, but it can also be styled while dry.

[0004] Existing hair styling tools typically use relatively thick heating plates or heating tubes, which provide a certain amount of heat capacity. These heating plates or heating tubes are heated by heaters mounted on the inner surface of the heating plate / heating tube. Due to the heat capacity, the heating plate / heating tube requires time to heat up, and once heated, it may take a considerable amount of time to cool down. This heat capacity makes it difficult to control the heating of the hair and can lead to overheating or underheating. The applicant and other companies have recently been developing hair styling tools using heaters with lower heat capacity, allowing the heaters to heat and cool down more quickly. Therefore, such low-heat-capacity heaters are more sensitive and can more easily change temperature dynamically over time.

[0005] However, further improvements are needed for these low heat capacity heaters and the components and systems used therein. For example, how they are constructed and installed within the appliance, and how to prevent the formation of high temperature gradients (hot spots) when the heater surface is loaded in an uneven manner.

[0006] The purpose of this invention is to solve or at least partially eliminate one or more of the above-mentioned problems. Summary of the Invention

[0007] According to one aspect, the present invention provides a hair drying and / or styling appliance comprising a multilayer heater having multiple functional layers, wherein the multilayer heater is mounted within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multilayer heater and is heated by conductive heating, wherein the multilayer heater comprises: a heater electrode layer including one or more heater electrodes formed of a conductive material, the one or more heater electrodes generating heat when an electric current passes through the one or more heater electrodes; and at least one upper dielectric layer located above the heater electrode layer to electrically insulate the heater electrode layer; wherein the upper surface of the dielectric layer and / or a coating applied to the upper surface of the dielectric layer provides the hair contact surface of the multilayer heater.

[0008] The heater can have a power greater than 2 W / cm². 2 And less than 100 W / cm 2 Preferably greater than 8 W / cm 2 The power density. The upper dielectric layer preferably has a dielectric breakdown strength greater than 500 volts and a power density of 9.35 × 10⁻⁶ volts. -4 KW -1 cm 2 With 0.8KW -1 cm 2 The thermal resistance between them.

[0009] The dielectric layer can be directly mounted on the upper surface of the heater electrode layer. Alternatively, the multilayer heater may also include a sensor layer with one or more conductive rails whose resistance changes with temperature, wherein the dielectric layer is directly mounted on the upper surface of the sensor layer. In this case, a second dielectric layer can be disposed between the sensor layer and the heater electrode layer.

[0010] According to another aspect, the present invention provides a multi-layer heater for hair drying and / or styling appliances, the multi-layer heater having a plurality of functional layers bonded together, wherein the multi-layer heater provides a hair contact surface for heating hair in contact with the multi-layer heater, wherein the multi-layer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a first conductive material (e.g., steel), which generate heat when an electric current passes through the one or more heater electrodes; a heat dissipation layer comprising one or more heat sinks, each heat sink being formed of a second conductive material (e.g., copper) different from the first conductive material; and at least one dielectric layer sandwiched between the heater electrode layer and the heat dissipation layer. The multi-layer heater may have a thickness measured on all of the plurality of layers of the multi-layer heater, the thickness being between 30 μm and 2 mm, and preferably between 75 μm and 300 μm.

[0011] In some embodiments, the heater electrode layer includes a plurality of independently powered (i.e., independently controllable) heater electrodes formed of a conductive material, each heater electrode generating heat when current passes through it. The plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating regions arranged along the length of the hair contact surface of the multilayer heater. In this case, the heat sink layer may include a plurality of heat sinks, at least one of which is positioned aligned with each heating region.

[0012] According to another aspect, a multi-layer heater for hair drying and / or styling appliances is provided, the multi-layer heater having a plurality of functional layers bonded together, wherein the multi-layer heater provides a hair contact surface for heating hair in contact with the multi-layer heater, wherein the multi-layer heater includes: a heater electrode layer comprising one or more heater electrodes formed of a first conductive material, the one or more heater electrodes generating heat when an electric current passes through the one or more heater electrodes; a heat dissipation layer comprising one or more heat sinks, each heat sink being formed of a second conductive material different from the first conductive material; and at least one dielectric layer sandwiched between the heater electrode layer and the heat dissipation layer.

[0013] The heater electrode layer may include multiple independently powered heater electrodes formed of a conductive material. When current passes through the multiple heater electrodes, the multiple heater electrodes generate heat. The multiple heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding multiple heating areas arranged along the length of the hair contact surface of the multilayer heater. The heat sink layer may also include one or more heat sinks.

[0014] Multilayer heaters typically have thicknesses measured on all of the plurality of layers of the multilayer heater, said thicknesses being between 30 μm and 2 mm, and preferably between 75 μm and 300 μm.

[0015] In some examples, the first conductive material includes steel, and the second conductive material includes copper.

[0016] The multilayer heater preferably has an upper dielectric layer disposed on the surface of the electrode layer of the heater, and the upper dielectric layer has a dielectric breakdown strength greater than 500 volts and a dielectric strength of 9.35 × 10⁻⁶ volts. -4 KW -1 cm 2 With 0.8 KW -1 cm 2 The thermal resistance between them.

[0017] According to another aspect, a hair drying and / or styling appliance is provided, comprising a multilayer heater having multiple functional layers bonded together, wherein the multilayer heater is mounted within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multilayer heater and is heated by conduction, wherein the multilayer heater comprises: a heater electrode layer including one or more heater electrodes formed of a conductive material, the one or more heater electrodes generating heat when current passes through them; at least one dielectric layer located above the heater electrode layer to electrically isolate the heater electrode layer; wherein the heater is supported within a housing of the appliance by a rigid support member; wherein terminals of the one or more heater electrodes are disposed on a connecting protrusion folded below the rigid support member; wherein a rigid circuit board is disposed below the rigid support member, the rigid circuit board carrying a drive and control circuitry for controlling the heating of the multilayer heater; and wherein a plurality of spring clips are configured to form an electrical connection between terminals on the rigid circuit board and terminals of the one or more heater electrodes disposed on the connecting protrusion.

[0018] According to another aspect, a hair drying and / or styling appliance is provided, comprising a multilayer heater having multiple functional layers bonded together, wherein the multilayer heater is mounted within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multilayer heater and is heated by conduction, wherein the multilayer heater comprises: a heater electrode layer comprising a plurality of independently powered heater electrodes formed of a conductive material, the plurality of heater electrodes generating heat when current passes through the plurality of heater electrodes, wherein the plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating areas arranged along the length of the hair contact surface of the multilayer heater; and at least one upper dielectric layer located above the heater electrode layer to electrically isolate the heater electrode layer; and wherein the number of heating areas per centimeter length of the multilayer heater is between 0.6 and 2.5.

[0019] The multilayer heater may have a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 75 μm and 300 μm.

[0020] In some embodiments, the average thermal conductivity of the layers constituting the multilayer heater is less than 300 W / mK (preferably less than 200 W / mK) and greater than 80 W / mK. The average thermal conductivity may be an average of the thickness of the multilayer heater.

[0021] The heater can be configured to provide 4 Wcm-2 and 10 Wcm -2 The maximum power density between, and in some cases, at 4 Wcm -2 and 25 Wcm -2 between.

[0022] In some embodiments, the maximum permissible temperature of the heating zone is less than 250°C.

[0023] A heat dissipation layer comprising multiple heat sinks can be provided to regularize or homogenize the temperature within the heating area. Typically, one heat sink is provided for each heating area. Each heat sink can be formed as an island to reduce heat diffusion from one heating area to adjacent heating areas. Heat sinks can be formed as interconnected islands that are electrically interconnected and thermally decoupled from adjacent islands (by minimizing the contact area between adjacent islands), or adjacent heat sinks may not contact each other at all. Each heat sink is typically formed of metal or other highly thermally conductive materials.

[0024] Heat sinks can be spaced apart from each other in a plane perpendicular to their thickness by solid or semi-solid materials, the thermal conductivity of which is less than 35 W / mK, and most preferably less than 0.3 W / mK.

[0025] In some embodiments, the multilayer heater further includes one or more of the following: i) A low-friction coating, the upper surface of which provides a hair contact surface for the multilayer heater; ii) A lower dielectric layer disposed below the heater electrode layer; and iii) An auxiliary heater electrode layer, comprising one or more heater electrodes disposed below the heater electrode layer and a dielectric layer disposed between the heater electrode layer and the auxiliary heater electrode layer.

[0026] One or more layers of a multilayer heater can be bonded together using adhesives, thermal bonding, physical vapor deposition, screen printing, or other coating methods. One or more dielectric layers may include polyimide.

[0027] In some embodiments, the upper dielectric layer may also be a low-friction layer providing a hair-contact surface for the appliance. The upper dielectric layer may be formed as a coating or paint applied directly to the surface of the heater electrode.

[0028] One or more dielectric layers may include polyimide, liquid crystal polymer, or other high-temperature polymers capable of withstanding temperatures exceeding 200°C.

[0029] Typically, multilayer heaters are flexible and bonded (using adhesive layers) to a rigid structure to provide rigidity to the multilayer heater. Depending on the shape of the rigid support structure, the multilayer heater can be shaped to provide a flat, curved, and / or ribbed heating surface. However, embodiments in which the multilayer heater is not fixed and remains flexible can also be provided.

[0030] In a preferred embodiment (where the hair drying and / or styling appliance is a hair styler), the multi-layer heater provides a flat heating surface and has curved edges that provide a bent heating surface. This allows for better control over the user's hair during the curling process, during which the appliance rotates and the hair is stretched on the curved edges of the heater.

[0031] Multilayer heaters may have flat, curved, and / or ribbed heating surfaces. In some embodiments, a multilayer heater provides a flat heating surface and has curved edges that provide a curved heating surface.

[0032] A controller can be provided, which is configured to control the electrical application to the multilayer heater in order to control the heat generated by the multilayer heater.

[0033] The appliance can take the form of a single-arm appliance, such as a brush or curling iron, or a double-arm device, such as a hair styler or straightener, or a dual-function appliance, such as the applicant's "Duet" hair styling device. The appliance is typically a handheld, portable device with a handle portion for the user to hold and a hair contact portion for contacting and heating the hair.

[0034] According to another aspect, the present invention provides a method for manufacturing a hair drying and / or styling appliance, the method comprising: providing a multilayer heater having a plurality of functional layers bonded together; installing the multilayer heater within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multilayer heater and is heated by conduction; wherein providing the multilayer heater comprises: providing a heater electrode layer comprising a plurality of independently powerable heater electrodes formed of a conductive material, the plurality of heater electrodes generating heat when current passes through the plurality of heater electrodes, wherein the plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating regions arranged along the length of the hair contact surface of the multilayer heater; and providing at least one upper dielectric layer located above the heater electrode layer to electrically insulate the heater electrode layer; and wherein the number of heating regions per centimeter length of the multilayer heater is between 0.6 and 2.5. Attached Figure Description

[0035] Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1a A schematic diagram of an exemplary hair styling device is shown; Figure 1b Showing the hair styling device in use; Figure 2 This is a block diagram showing the main electronic components of the hair styling device shown in Figure 1; Figure 3a This is an exploded view of the heater that forms part of the hair styling device shown in Figure 1. Figure 3b yes Figure 3a A partial transparent view of the assembly of the heater shown; Figure 4a The heating area on the heating surface of the heater shown in Figure 3 is schematically illustrated. Figure 4b An alternative arrangement of the heating area is schematically shown; Figure 5 An alternative arrangement of heating zones with different sizes and shapes is schematically shown; Figure 6a The diagram shows a heating region formed on a tubular substrate used for curling pliers, etc. Figure 6b The heating area can be arranged on a curved substrate that can be used on a heating brush; Figure 7 Showing hair strands that partially overlap with the heater regions Z2 and Z4; Figure 8 A cross-sectional view showing another example of a low heat capacity heater, which has curved edges and a support substrate, is shown. The heater is attached to the support substrate using an adhesive or via a diffusion bonding process (e.g., by melting them together) or via an in-mold labeling process. Figure 9 It constitutes Figure 8 Partial exploded cross-sectional perspective view of different layers of the heater shown; Figure 10 It shows the composition Figure 8 A plan view of the heat dissipation layer of a portion of the heater shown; Figure 11 Showing the composition Figure 8 The main heating element layer is a portion of the heater shown. Figure 12 It is shown Figure 8 The diagram shows a simplified block diagram of the heater electrodes used to heat the heater and sense the temperature of the heated area. Figure 13A schematic diagram of an alternative hair styling device with an alternative heater arrangement is shown; Figure 14a Show Figure 13 The two heater assemblies shown are oriented when the alternative hair styling device is installed inside the housing of the hair styling device; Figure 14b yes Figure 14a The longitudinal cross-sectional view of the top heater assembly shown; Figure 14c This is an exploded view showing the components of each heater assembly; Figure 14d When the user makes Figure 13 A cross-sectional view of the two heater assemblies when the arms of the hair styling device are closed and the hair strand passes between the hair contact surfaces of the two heater assemblies. Figure 15 It is shown that it is used for Figure 14a An exploded view of each layer of the layered heater in each heater assembly shown; Figure 16 Show Figure 15 The form of the main heater electrode layer of the layered heater is shown; Figure 17 a shows Figure 15 The form of the fuse and connecting layer of the layered heater is shown; Figure 17 b shows more details Figure 17 A portion of the fuse and connecting layer shown in Figure a; Figure 18 The process of bending the flexible layered heater over a rigid support and bonding it to the rigid support is shown. Figure 19a As shown Figure 18 The base and upper extrusion section of the press shown are used to bend the flexible layered heater over a rigid support. Figure 19b The diagram shows a transverse cross-sectional view of the base and upper extrusion portion during the bending of the flexible layered heater around the rigid support. Figure 19c It is a perspective view of the base, showing the base and recess in which the rigid support and flexible heater are placed during bending; Figure 20 It is a partially exploded cross-sectional perspective view of the different layers that make up the alternative heater; Figure 21a Showing the composition Figure 20 The heater shown includes a portion of its heat dissipation and fusible layer; Figure 21b The common terminal of the heater electrode is shown connected to Figure 21aThe form of the heat dissipation and busbars on the fuse layer is shown; Figure 22 This is a partially exploded cross-sectional perspective view of another heater assembly; Figure 23a This is an exploded view of the flexible heater, adhesive layer, and heater support, viewed from above. Figure 23b It is observed from below. Figure 23a An exploded view of the flexible heater, adhesive layer, and heater support shown. Figure 24 The main heating electrode layer, which constitutes a part of the heater shown in Figure 23, is shown. Figure 25 This shows a heat-diffusion filament layer that forms part of the heater shown in Figure 23; Figure 26 shows more details Figure 25 The fuse circuit system shown; Figure 27a Figure 23 is a cross-sectional view of the heater assembly, showing the fuse when it is intact; Figure 27b Figure 23 is a cross-sectional view of the heater assembly, showing when the fuse melts due to overheating; Figure 28 This is a simplified schematic diagram of a drive and control circuit system that can be used to control the heating of the heater shown in Figure 23; Figure 29 An exemplary embodiment of a heater having three dielectric layers, a hair contact layer, and an electrode layer is shown; Figure 30 An example of a stepped structure between dielectric layers is shown; Figure 31 An example of a stepped structure is shown in both the media layer and the hair contact layer, wherein each of the media layers has some contact with the hair contact layer; Figure 32 Another example of a stepped structure between media layers is shown, wherein each of the media layers has some contact with the hair contact layer; Figure 33 a shows a meandering heater track with contacts at either end of the track; Figure 33 b shows a fully covered heater track with busbar contacts; Figure 34 An exemplary hair-curling styling device including a heater is shown; Figure 35a A side view of a hair styling device including an active cooling system is shown. Figure 35b Show Figure 35a A perspective view of the hair styling device; Figure 36 This illustrates an exemplary use of the hair styling device; Figure 37 Show Figure 35a and Figure 35b An internal view of the hair styling device; Figure 38a A perspective view showing another exemplary embodiment of a hair styling device including an active cooling system; Figure 38b Show Figure 38a An internal view of the hair styling device; Figure 39a A perspective view showing yet another exemplary embodiment of a hair styling device including an active cooling system; Figure 39b Show Figure 39a An internal view of the hair styling device; Figure 40 An internal view is shown of yet another exemplary embodiment of a hair styling device including an active cooling system; Figure 41a The flexible heater is shown before it is formed above the heater support; Figure 41b Showing the formation after the heater support. Figure 41a The flexible heater shown; Figure 41c This illustrates the use of spring clips to connect terminals on a rigid PCB to terminals on a connection protrusion of a flexible heater; and Figure 41d Show Figure 41c The spring clip shown is in a compressed state. Detailed Implementation

[0036] Overview of hair styling devices

[0037] Figure 1a A handheld (portable) hair styler 101 is shown. The hair styler 101 includes a first movable arm 104a and a second movable arm 104b, which are coupled at their proximal ends to a shoulder or hinge 103. The first arm 104a supports a first heater 106a at its distal end, and the second arm 104b supports a second heater 106b at its distal end. The first heater 106a and the second heater 106b are opposite each other and are brought together when the first arm 104a and the second arm 104b move from an open configuration to a closed configuration. Figure 1bAs shown, during use, the hair bundle 140 is clamped between the two arms 104, causing the user's hair to come into contact with and be heated by the external heating surfaces of the heaters 106a and 106b. Therefore, when the user pulls the hair styler 101 along the hair bundle 140, the hair bundle 140 is heated to a suitable temperature by conduction for styling.

[0038] A user interface 111 is provided to allow users to set user-defined parameters and to allow the device to output information to the user. For example, a desired operating temperature can be set via the user interface 111. The user interface 111 may have a dashboard, buttons, or a touch display for allowing users to input information into the device 101, and may have indicator lights, displays, sound generators, or haptic feedback generators for outputting information to the user. In this embodiment, the user interface 111 also includes control buttons or switches 114 to enable the user to turn the device 101 on or off; and indicator lights 115 to indicate whether power is on.

[0039] A printed circuit board assembly (not shown) may be disposed at any suitable location within the housing of device 101 and carries a control circuitry system for controlling the operation of device 101 and for controlling interaction with the user via user interface 111. In this example, power is supplied to device 101 via power cord 105 from a power source located at the end of the device. The power source may be AC ​​mains power or DC power. However, in an alternative embodiment, the power source may include one or more DC batteries or battery cells (which may be rechargeable from AC mains or DC power via a charging cable, for example), thereby enabling device 101 to be a wireless product. In the case that device 101 is a wireless product, the power source may be included within device 101.

[0040] In use, device 101 is turned on, allowing electricity to flow through heaters 106 to heat them. The user then opens the first arm 104a and the second arm 104b, and typically starting from the root of the hair (i.e., near the scalp), a certain length or a tuft of hair 140 (which may form a tuft) is introduced between arms 104a and 104b, laterally passing through heaters 106a and 106b. The user then closes arms 104a and 104b, holding the hair 140 of a certain length between the first arm 104a and the second arm 104b, and then pulls the hair through the closed arms (e.g., ...). Figure 1b(As shown in Figure 1). In this embodiment, the outer surface (hair contact surface) of the heater 106 is flat, so the hair styler 101 can be used to straighten the user's hair. The hair styler 101 shown in Figure 1 can also be used to curl hair by rotating the device 101 by an angle of approximately 180 degrees or more after the hair has been clamped between the arms 104a, 104b and before the device 101 has been moved along the hair bundle 140.

[0041] Hair has a relatively high heat capacity and absorbs a significant amount of heat energy when in contact with the heating surface of heater 106. Heater 106 must quickly return the lost heat energy to the heating surface; otherwise, the temperature of the heating surface will drop, potentially affecting the quality of the thermal shaping. If the temperature of heater 106 drops below the temperature required to raise the hair temperature above its glass transition temperature, the hair will not maintain its shape. However, if the hair is heated to too high a temperature, it will suffer severe damage. Thus, device 101 must be able to control the temperature so that the heating surface of heater 106 remains within a specific temperature range. Furthermore, the heating surface must maintain this temperature range when hair is frequently and rapidly loaded onto and unloaded from the heating surface, and when the hair remains on the heating surface for extended periods.

[0042] Control circuit system

[0043] Figure 2 This is a simplified block diagram of the control circuitry system 216 that controls the operation of the hair styler device 101 shown in Figure 1. As shown, the control circuitry system 216 includes a power supply 221, which in this embodiment draws power from a battery power source (not shown). A power input can be provided to charge the battery via an AC-to-DC converter (not shown), which can be external to or internal to the device 101. Alternatively, the power supply 221 can draw power from an AC mains power input.

[0044] In this example, power is supplied to heater 206 to heat the user's hair. The power supplied to heater 206 is controlled by controller 228 having microprocessor 229. The power supplied to heater 206 is controlled by drive circuitry 223 (which may include one or more power semiconductor switching devices), which controls the application of AC mains voltage or DC voltage from AC mains via a power source or from a battery to heater 206 according to instructions from microprocessor 229. Microprocessor 229 is coupled to memory 230 (which is typically non-volatile memory) storing processor control code for implementing one or more control methods that control the heating of heater 206 based on a desired operating temperature of heater 206 and a sensed temperature of the heater obtained from temperature measurement circuitry 225. Temperature measurement circuitry 225 may be a temperature sensor, such as a thermistor, or it may use circuitry that senses the resistance of heater electrodes used to heat heater 206, the resistance of which depends on the temperature of the heater electrodes.

[0045] Figure 2 User interface 211 is also shown coupled to microprocessor 229, for example to provide one or more user controls and / or output indications, such as visual indications or audible alarms. The outputs (one or more) may be used to indicate to the user, for example, whether they have inserted too many hairs between the heaters 206, or whether they have moved device 101 too fast along hair bundle 140.

[0046] Finally, the control circuitry includes a communication circuitry 227 to allow the device to communicate with remote sensors, remote servers, or remote applications (e.g., on a mobile phone). The communication circuitry 227 can use, for example, Bluetooth, Wi-Fi, and / or 3GPP communication protocols to communicate with remote devices.

[0047] heater

[0048] Heaters 306a and 306b are low heat capacity heaters, and therefore can heat and cool rapidly. Figure 3a and Figure 3b Exemplary embodiments of such heaters 306a and 306b are shown, comprising a stack of thin layers. See specifically... Figure 3aHeaters 306a and 306b include an upper dielectric (electrically insulating) layer 362, an electrode layer 363 having a plurality of individual heater electrodes 367, and a lower dielectric layer 366 electrically insulating the heater electrodes 367 from other components mounted behind heaters 306a and 306b. These three layers 362, 363, and 366 are bonded together by an adhesive layer (pressure-set or thermosetting) or by diffusion bonding of contact materials (e.g., melting them together), and these three layers 362, 363, and 366 define heater 306, which is very thin (with a total thickness of 30 μm to 1000 μm (preferably between 75 μm and 300 μm) for low-voltage operation (less than about 40 volts), and a total thickness of 0.8 mm to 2.0 mm for AC operation) and has a very low heat capacity. The upper surface of layer 362 forms the hair contact surface of heater 306. However, if layer 362 itself does not have this non-stick property, a non-stick coating can be applied to the upper surface of layer 362 to allow the user's hair to pass through the heating surface. The hair contact surface of the heater is a single smooth surface over which hair can pass. Adhesive layers 362, 363, and 366 define the flexible heater 306, and in the illustrated embodiment, the rigidity of the heater is provided by mounting heater layers 362, 363, and 366 to a rigid support 368 forming the base. These layers can be mounted to the rigid support after the layers themselves have been bonded together, or they can be bonded to the rigid support 368 one at a time (or multiple at a time). If a flexible heater is required, the rigid support 368 is not needed, or if a support is used, it can be a non-rigid support. Therefore, in this embodiment, there is no heater plate or heater tube heated by heater 306; instead, heater 306 directly heats the user's hair. This provides a hair styler 101 with very low heat capacity, so it can heat up and cool down faster than existing stylers.

[0049] In the illustrated embodiment, there are ten heater electrodes 367, each serpentinely traversing the width of heater 306, folding twice such that each heater electrode spans the width three times. The end of each heater electrode 367 is electrically connected via a lower dielectric layer 366 to an electrical connection within a rigid support 368, which is connected to an electrical connector 370. A drive circuit system 323, mounted within one of the arms 104, is connected to the heater electrodes 367 via the electrical connector 370 and applies current to each heater electrode 367 to control the heat generated by each heater electrode 367. The electrical connector 370 extends from the surface of the rigid support 368 away from the surface layer 362 (in... Figure 3a As shown in Figure 3c, it extends directly away from the upper layer 362, but it can also be set to extend in the vertical direction.

[0050] Therefore, each heater electrode 367 creates a separate heater region 467 on the hair contact surface of the heater 306, which spans the width of the heater 306 (referred to as the x-direction), and the heater electrodes 367 are arranged one after another along the length of the heater 306 (y-direction). Figure 4a and Figure 4b A schematic diagram showing different arrangements of such heating zones 467 is provided. Figure 4a Showing with Figure 3a and Figure 3b The arrangement corresponds to the arrangement of the heating zones, where heating zones 467-1 to 467-10 are arranged only along the y-direction. Figure 4b An alternative arrangement is shown, in which heating regions 467-1 to 467-16 are arranged in both the x and y directions. This can be achieved by arranging them side-by-side in the width direction (x-direction) as follows: Figure 3a The two sets of heater electrodes 367 shown are used to provide this arrangement of heating regions 467. The heater 306 can be divided into any number of heating regions 467 in this manner, and can include any number of heating regions along the x and y directions. Specifically, although... Figure 4b Two regions along the x-direction are shown, but more regions along the x-direction could also be provided. The heating regions 467 of heaters 406a and 406b can operate (heat) independently, which can help reduce hot / cold spots when using heaters 306 with very low heat capacity (such as those shown in Figure 3).

[0051] The heating areas shown in Figure 4 are all of the same size. Of course, heating areas of different sizes 467 can be provided, such as... Figure 5 As shown, Figure 5 A heater 506 is shown having seven heating zones of different sizes (labeled 5Z1 to 5Z7). The manner in which the heater electrodes 367 are arranged to define these zones of different sizes will be understood by those skilled in the art and will not be described in detail herein.

[0052] The aforementioned heating area 467 constitutes part of a heater having a flat hair contact surface. The heater is not limited to a flat hair contact surface and can be configured for use in a tubular form, wherein the heating areas designated 6Z1 to 6Z4 (e.g., Figure 6a (As shown) For example, in hair curling devices or used in a curved form, the heating areas marked 6Z1 to 6Z6 (such as...) Figure 6b (As shown) For example, it is used in heated hair brushes. The heater surface can have a corrugated or ribbed shape to provide a curling device.

[0053] The temperature of each heating zone 467 is independently controllable. Each heating zone 467 can be set to a target temperature. The target temperature for each heating zone 467 can be different. A separate temperature sensor can be provided to sense the temperature of each heating zone 467, which is fed back to the microprocessor 229 to allow the microprocessor 229 to control the power delivery to the heater electrode 367 of the corresponding heating zone 467. Alternatively, if the heater electrode 367 is formed of a material with a positive temperature coefficient (PTC) or a negative temperature coefficient (NTC) (causing its resistance to change with its temperature), the temperature of each heating zone 467 can be determined by determining the resistance of the corresponding heater electrode 367. Therefore, the microprocessor 228 can control heating based on each zone to reduce the difference between the actual temperature of the heating zone 467 and the target temperature of that heating zone 467.

[0054] Determine the size of the heating area

[0055] One problem with the low heat capacity heater 306 is regulating the hair contact surface temperature in the localized hair-loading area of ​​the heater within desired temperature limits without simultaneously causing overheating in the unloaded areas. Specifically, when a user loads hair strands 140 onto heater 106, some parts of the heater will be loaded with hair, while others will not. When hair is loaded, more power is supplied to heater 306 to ensure that all areas on the hair contact surface can be kept within and / or restored to the desired operating temperature limits. The aforementioned low heat capacity heater 306 is relatively thin, and the dielectric layer is formed of a material with a relatively low thermal diffusivity. If there is only a single heating area, and therefore only a single continuous heater electrode 364 extending across the entire length and width of heater 306, then when more power is supplied to heater 306 to restore the temperature drop in the localized hair-loading area, the unloaded areas will overheat, which could cause the heater material to exceed its maximum operating temperature, or cause the overheated areas to burn the relatively small hair strands / clumps in contact with them. Overheating can be prevented by using a material with high thermal diffusivity in the layers constituting the heater, and / or by increasing the thickness of the layers constituting the heater, and / or by dividing the heater 306 along its length or along its length and width into multiple individually powered and controlled heating zones 367. Increasing the layer thickness increases the heat capacity of the heater 306, which is undesirable, and materials with the required dielectric strength and high thermal diffusivity (and suitable for mass-produced consumer products) are limited. Therefore, the inventors have divided the heater 306 into multiple heating zones. These heating zones may have equal and / or unequal dimensions and may be arranged regularly and / or irregularly along the width and length of the heater.

[0056] However, overheating can still occur within a single heating zone. For example, if one half of the heating zone is loaded with hair (assuming this is the actual worst-case scenario during operation), while the other half is unloaded, the hair-loaded half will cause the temperature of that portion of the heating zone to drop, resulting in more electricity being applied to that entire heating zone. The applied electricity will bring the average temperature of the heating zone back to the desired operating temperature, but the unloaded portion of the heating zone will be above the average temperature. This temperature rise may be sufficient to cause the unloaded portion to overheat. Simultaneously, the loaded portion of the heating zone will be below the average temperature, resulting in reduced heat transfer and decreased shaping performance. This situation occurs in... Figure 7 The diagram shows hair bundles 740 located on heating regions 7Z2, 7Z3, and 7Z4, with heating region 7Z3 fully loaded with hair, while heating regions 7Z2 and 7Z4 are only partially loaded with hair. This problem can be mitigated by making the heating regions very small, but this is expensive due to all the connections required to connect each heater electrode 367 of each heating region back to the drive circuit system 223, and the number of control switches in the drive circuit system 223 required to control the power supply to each heater electrode 367. The inventors have discovered that, for a given maximum permissible temperature within the heater, the maximum size of the heating region can be defined, depending on the maximum power density of hair that can be extracted from the heating region and the material properties and thickness of the layers constituting the heating region.

[0057] Specifically, if we assume that only half of the heating region 467 is loaded with hair, then the maximum temperature that occurs in the unloaded half of the heating region 467 when hair is loaded can be defined by the following equation:

[0058] in, = The maximum temperature (°C) that may occur on the surface of the heater in the unloaded half (worst case) of each heating zone; = Target operating temperature or average temperature (°C) for each heating zone; = The power density (Wm) required to heat the hair passing through the surface to the desired styling temperature. -2 ); W = the width of the heated area measured perpendicular to the movement of the hair on the surface; = Total thickness of the layers constituting the heating zone; and = Average thickness thermal conductivity of the thin layer constituting the heating zone.

[0059] If we assume that the average thickness and thermal conductivity of each constituent layer of the heating region 467, and the total thickness of the layers constituting the heating region 467, are known and fixed (for any given device), then the required region width (W) can be determined using the above formula, and thereby the number of divisions along the length of the heater can be determined to prevent overheating of the unloaded half when hair is loaded on the other half of the heater, and to provide more power to maintain the hair contact surface temperature and / or restore the hair contact surface temperature to the desired operating limits. Therefore, for a given surface area that must be covered with the heater technology under consideration, the number of heating regions that should be set along the length of the given surface area can be determined using the above formula, such that the maximum operating temperature of the heater material is not exceeded when operating each heating region 467, nor does the temperature of the unloaded portion of the heating region 467 exceed the maximum temperature. This maximum temperature may cause relatively small strands of hair to burn in contact with such an overheated area of ​​the heated zone.

[0060] Specifically, the required division along the length can be determined according to the following formula: in, L = Length of the heater plate (in the direction perpendicular to where the hair typically travels on the surface); = The number of regions to be divided along the length of the heater plate; = The maximum permissible temperature (°C) on the surface of the heater required to avoid damaging the hair or the heater (possible in half of the unloaded (worst-case) heating zones); = Target operating temperature or average temperature (°C) for each heating zone; = Average thickness thermal conductivity (Wm) of the layers constituting the heating zone -1 °C -1 ); = Total thickness of the layers constituting the heating zone; and = The maximum power density (Wm) required to heat the hair passing through the surface to the desired styling temperature. -2 ).

[0061] For hair shaping devices, the inventors have discovered the following suitable ranges for these parameters: Peak power density required for styling dry hair ( Typically greater than 4 W / cm² and less than 50 W / cm², preferably greater than 8 W / cm² and less than 25 W / cm² The average thermal conductivity of each layer constituting the heating zone ( (Calculated by averaging the depth of each layer) is between 15 W / mK and 300 W / mK, preferably between 80 W / mK and 200 W / mK.

[0062] To manage (or ideally avoid) hair damage, the maximum permissible temperature of the heating zone is below 250°C, more preferably below 220°C, and most preferably below 200°C.

[0063] Due to manufacturing limitations, the total thickness of the various layers constituting the heater ( (less than 300µm, but not less than 75µm)

[0064] The target operating temperature of the heater ( (Between 150°C and 230°C)

[0065] Operating within these ranges, the inventors have discovered that the number of heating zones required per unit length (cm) along the length of the heater is between 0.6 / cm and 2.5 / cm, which corresponds to a zone width (in the length direction of the heater) between 0.4 cm and 1.7 cm.

[0066] Of course, this also applies to cases where there are no multiple regions in the width direction of the heater (for example, this is for...). Figure 4a The single-row case is shown. If multiple rows of heating areas 467 are set along the length of the heater (e.g., Figure 4b As shown in the figure, in order to avoid the above-mentioned overheating problem, each row of heating area 467 should meet the limitations defined above.

[0067] Alternative heater arrangement

[0068] Figure 8 The image shows a first alternative flexible heater 806, with an exploded cross-sectional view of the heater 806 and substrate 868 on the left and a perspective view of the heater 806 and substrate 868 on the right. Figure 8 As shown, heater 806 has curved edges 872-1 and 872-2, which are shaped to match the shape of the upper surface 874 of rigid support substrate 868, such that flexible heater 806 can be firmly bonded to the upper surface of rigid substrate 868 using diffusion bonding (thermoforming) with an adhesive or underlying material, or the flexible heater 806 can be firmly bonded by overmolding, wherein in overmolding, a carrier is injection molded onto the back side of the flexible heater within a mold. The curved edges of heater 806 can be formed, for example, using a thermoforming process. Figure 8It is also shown that one or more surface-mount electronic components 876 may be attached to the underside of the heater 806. These components may be, for example, thermistors for sensing the temperature of the heating region 867 of the heater 806, or fuses that can cut off the power to the heater electrodes of each or all regions in the event of overheating. Figure 8 Also shown is a control printed circuit board (PCB) 878, which carries... Figure 2 The drive and control electronics 216 shown are for the heating of different heating zones 867 of the control heater 806.

[0069] As previously described, heater 806 is formed by multiple discrete layers mechanically or chemically bonded together. Each layer has a thickness between about 1 μm and 150 μm, preferably between 1 μm and 100 μm, more preferably between 10 μm and 70 μm, or between 2 μm and 10 μm. Figure 9 The exploded cross-sectional perspective view shows the different layers that make up part of heater 806. A description of each layer is given below.

[0070] Low-friction coating 981 (optional)

[0071] This is an optional layer and can be added to create a smooth, low-friction surface to enhance the user experience by subjecting the heater 806 to less friction with the hair. The layer should be as thin as possible (e.g., between 10 μm and 50 μm, preferably between 1 μm and 3 μm) to reduce thermal resistance from the heater 806 to the hair, while still being durable and scratch-resistant enough.

[0072] After the remainder of the heater 806 has been manufactured and assembled around the fixed substrate 868, this layer is typically applied last, possibly as a spray coating (e.g., Cerasol, a ceramic coating). This is necessary for Cerasol because the coating is prone to cracking when bent, and once applied, it reduces the heater's natural flexibility; therefore, Cerasol should be applied once the heater 806 has been formed into its final shape.

[0073] Alternatively, the coating may comprise multiple layers, including, for example, a primer layer (about 6 μm), an undercoat layer (about 25 μm), and a topcoat layer (about 10 μm).

[0074] This layer can also have combined functions with other proposed layers (e.g., not just providing low friction), such as dielectric strength / electrical isolation, provided that the material is sufficiently electrically insulating.

[0075] Heat dissipation layer 982 (optional)

[0076] This is also an optional layer, and when this layer is provided, it helps dissipate heat within each heating zone 467 to ensure that the temperature of each heating zone 467 remains acceptablely uniform during typical use. As mentioned above, if the heating zone 467 is partially loaded with hair and is large enough, the unloaded portion of the heating zone 467 may develop unacceptably high temperatures, while the loaded zone will be too cold because heat cannot flow sufficiently from the hot zone to the cold zone. The anisotropic thermal characteristics of the meandering heater electrodes 367 exacerbate this problem, and since the control electronics 216 typically operates based on the total resistance of the heater electrodes constituting the heating zone 467 to maintain an “average” temperature within the heating zone 467—from the control electronics 216’s perspective—the heating zone 467 will be at the “correct” temperature, despite having hot and cold zones.

[0077] Each heating region 467 has its own heat sink, which is thermally isolated from the heat sinks used for adjacent regions (exhibiting high thermal resistance / low thermal conductivity). This is desirable to prevent heating region 467 from heating adjacent heating regions 467, which could increase power consumption, reduce preheating time, and complicate region-based power consumption algorithms by adding crosstalk. Figure 10 An example configuration of heat sink layer 1082 is shown. As illustrated, in this example, there are 20 heat sinks 1091-1 to 1091-20, each formed of a material with relatively high thermal conductivity (e.g., copper). Each heat sink 1091 is spaced apart from its adjacent heat sink 1091 and effectively forms islands of thermally conductive material in the corresponding heating area. The heat sinks 1091 can be spaced apart from each other by a solid material having a thermal conductivity of less than 35 W / mK, or they can be spaced apart by air. The heat sinks 1091 can be formed, for example, by taking a planar layer of metal (such as a copper layer) that is bonded to the underlying layer and then etching the copper layer to physically separate the individual heat sinks 1091 (so that they do not contact each other). Assuming there is a break between adjacent heat sinks 1091, heat from one heating area 467 is difficult to enter the adjacent heating area 467. A solid material (one or more dielectrics and / or scratch-resistant, low-friction materials) disposed in the gap between adjacent heat sinks 1091 can be provided by PVD (physical vapor deposition) DLC (diamond-like carbon), adhesive films, coatings, or paints. The solid material can be the aforementioned coating 981, wherein the PVD (physical vapor deposition) DLC (diamond-like carbon), adhesive film, coating, or paint is applied to the heat dissipation layer 1082 after the etching process has formed the gap between adjacent heat sinks 1091. Alternatively, other suitable methods, such as masking and vapor deposition, can be used to provide a solid material in the gap between adjacent heat sinks.

[0078] The heat sink layer 1082 provides mechanical integrity to the entire heater 806, thus providing some protection against damage to the hair contact surface, which could otherwise expose the heater electrodes 367 below, potentially leading to a short circuit or loss of function.

[0079] Polyimide isolation layer 983

[0080] A polyimide insulating layer 983 provides electrical insulation between the hair contact surface of heater 806 (which, if optional layers 981 and 982 are not provided, can be the upper surface of this layer 983) and the main heater electrode layer. This layer 983 will have the lowest possible thermal resistance while still meeting the dielectric requirements of the layer. As the name suggests, this layer is formed of polyimide, but other dielectric materials can also be used. Because the layer is relatively thin, although its thermal conductivity is low (less than 0.2 W / mK), it does not significantly impede heat transfer between the main heater electrode and the hair contact surface. However, in the plane, it is able to prevent heat from diffusing from one heating region 467 to adjacent heating regions 467.

[0081] Main heater electrodes and sensing layer 984

[0082] Heat is generated in layer 984 by dissipating power from a power source (e.g., a power supply unit (PSU) or one or more batteries).

[0083] Layer 984 includes multiple independently controllable heater electrodes 367, each heater electrode defining a corresponding heating zone 467. "Independently controllable" means that each heating zone can be heated to any desired target temperature (or turned on / off) independently of other heating zones. Therefore, if needed, the setpoint temperature of one heating zone can be different from the setpoint temperatures of other heating zones. Figure 11 The form in which layer 984 is employed in this exemplary heater 806 is shown in more detail. As illustrated, in this example, there are twenty independently controllable heater electrodes 1164-1 to 1164-20, each heater electrode defining a corresponding heating region 467. Each heater electrode 1164 is formed by orbitals of resistive material, the geometry (orbit width, thickness, length) and material of which are specified to achieve the desired resistance and peak power density (W / cm²) based on the voltage output of the associated power supply. 2 )Require.

[0084] Each heater electrode 1164 is formed into a meandering pattern using, for example, chemical etching as a manufacturing process. More specifically, a solid layer of conductive material is set and then etched to form different heater electrodes 1164. Figure 11The straight lines shown are etched portions of layer 984, and the white portions in the figure indicate the meandering conductor paths that form heater electrode 1164. Other processes such as printing, thick film printing, physical vapor deposition, etc., can be used to form heater electrode 1164. In the illustrated example, adjacent heater electrodes 1164 share a common positive terminal (however, in other embodiments, they may share a common ground terminal) to reduce the number of electrical connections required between drive and control board 878 and heater 806. This common positive terminal is connected to the different heater electrodes via suitable vias 1165-1 to 1165-5, through which a connection circuitry (not shown) connects to the drive and control board 878. The other end of each heater electrode is connected to the drive and control board 878 via a corresponding switch (not shown) to allow independent control of the current flowing through each heater electrode 1164. As those skilled in the art will understand, having such a common positive (or ground) terminal is not necessary, and each heater electrode 1164 may be physically spaced apart from all other heater electrodes 1164, in which case each end of each heater electrode 1164 will be individually connected back to the drive and control board 878.

[0085] like Figure 11 As schematically shown, the ends of each heater electrode 1164 connected to the switch are positioned at the edge of the heater, and the direction of the meandering path changes in this edge portion (which corresponds to the portion of the heater that bends on the upper surface 874 of the rigid support substrate 868). The inventors have discovered that this arrangement facilitates the upward transfer of heat generated in the heater electrodes 1164 in these edge portions to the top surface of the heater, which is more likely to come into contact with the user's hair. However, if the device is twisted during use, causing the user's hair to come into contact with the bent edge portion, the hair will still be heated because the bent edge portion is heated.

[0086] The conductive material used in layer 984 is preferably PTC or NTC (e.g., stainless steel or copper), such that the resistance of heater electrode 1164 depends on its temperature. Therefore, the temperature of heating zone 467 can be determined by measuring the parameter that varies with the resistance of the corresponding heater electrode 1164. This eliminates the need for a separate temperature sensor for each heating zone, as a single sensor can be used to measure the temperature of each heating zone (see reference below). Figure 12 (As discussed).

[0087] Figure 12 This is a schematic diagram showing how the heater electrodes 1264 can be connected together and connected to the drive circuit system 1223 and the power supply 1221. (See diagram below.) Figure 12As shown, one end of each heater electrode 1264 is connected to a power supply 1221, and the other end is connected to corresponding switches (MOSFET switches in this case) 1295-1 to 1295-20. Switches 1295 are controlled by a microprocessor 1229. When a heater electrode 1264 needs to provide heat, the corresponding switch 1295 closes, connecting the heater electrode 1264 to ground via a resistor 12R. As a result, current flows from the power supply 1221 to ground, causing the heater electrode 1264 to heat up. The microprocessor 1229 can independently control the position of each switch 1295, allowing each heater electrode 64 to be powered independently.

[0088] When the temperature of the selected heating region 467 needs to be determined, the switch 1295 of the corresponding heater electrode 1264 is closed, and all other switches 1295 are opened. Thus, the selected heater electrode 1264 is connected in series with the resistor 12R. Since the heater electrode 1264 is formed of PTC or NTC material, the resistance of which changes with the temperature of the heater electrode 1264, the microprocessor 1229 can determine the resistance of the selected heater electrode 1264 by measuring the voltage drop across the resistor 12R (using operational amplifier 1297), and thus determine the temperature of the corresponding heating region 467. If the determined temperature is higher than the desired temperature of the heating region 467, the microprocessor 1229 can reduce the power applied to the heater electrode 1264; or if the heating region 467 is at a temperature lower than the desired temperature, the microprocessor 1229 can increase the power applied to the corresponding heater electrode 1264. Any suitable on / off control or PWM (pulse width modulation) control can be used to change the power applied to different heater electrodes 1264. The microprocessor 1229 can sequentially select each heater electrode 1264 to determine the temperature of each heater electrode 1264 / heating region 467.

[0089] Polyimide isolation layer (optional) 985

[0090] When an auxiliary heater electrode layer is provided, it is required to provide the necessary electrical isolation (insulation) between the auxiliary heater electrode layer and the main heater electrode layer 984. This polyimide layer 985 has low thermal resistance in the thickness direction while still meeting the dielectric requirements. Due to its relatively thin thickness, it will have a low thermal conductivity of less than approximately 35 W / mK in a plane perpendicular to its thickness. Other dielectric materials can be used instead of polyimide.

[0091] Auxiliary heater electrode layer (optional) 986

[0092] Some embodiments of heater 806 may benefit from the presence of an additional heating element layer 986. This additional layer 986 can be used to dissipate power (generate heat) from an auxiliary power source operating at a voltage different from the main power source 221; for example, the main power source could be a power supply, and the power source for the auxiliary heater electrode layer 986 could be one or more batteries or supercapacitors. In other embodiments, the main power source could be one or more batteries, and the auxiliary power source could be one or more supercapacitors. Alternatively, the conductors on the auxiliary layer 986 could serve as the main heater, while the conductors on the main heater electrode layer 984 could be used solely for temperature sensing, or vice versa.

[0093] The heater electrodes on the auxiliary layer 986 typically have the same form as the heater electrodes 1164 used in the main heater electrode layer 984, such that they will define the same heating region 467 as the heating region 467 defined by the heater electrodes 1164 on the main heater electrode layer 984. The paths taken by the heater electrodes on the auxiliary layer 986 do not need to follow the same paths as the corresponding heater electrodes 1164 formed on the main heater electrode layer 984. For example, although in Figure 11 In the main heater electrode layer 984, the main portion of each heater electrode 1164 (ignoring the edge portions of each heater electrode 1164) meanders along the longitudinal direction of the heater 806, but the corresponding heater electrodes of the auxiliary heater electrode layer 986 can be arranged to meander along the width direction of the heater 806. This arrangement will reduce the anisotropic thermal conductivity caused by the predominantly oriented track and can help diffuse heat flow within the heating region 467, especially when the heating region 467 is only partially loaded with hair.

[0094] Polyimide backing 987

[0095] This layer encapsulates and electrically insulates the bottom heating layer (main heating layer or auxiliary heating layer) to prevent accidental exposure and moisture ingress. The backing layer 987 electrically isolates the bottom heating layer from any surface-mount components present on the surface-mount layer 988 (discussed below) on the bottom of the heater 806. If desired, this dielectric layer 987 may be thicker than the upper dielectric layer to provide enhanced structural integrity for the flexible portion of the multilayer heater. Like other dielectric layers, this backing layer 987 need not be a polyimide layer and other dielectric materials can be used.

[0096] Rear surface mount component (optional) 988

[0097] This layer is used to mount components to the rear of the flexible heater 306. These components may be temperature sensors (e.g., thermistors) or other components involved in providing a fusible function for the heater (e.g., welding links).

[0098] This layer can be manufactured using standard chemical etching methods found in PCB manufacturing processes. Additional surface mount components can then be added.

[0099] This layer can be processed during manufacturing to provide a rough copper surface (e.g., "brown oxide" or "black oxide"). This allows for better bonding of the flexible heater 806 to the underlying support structure 868 when using the adhesive film 989.

[0100] High-temperature adhesive / adhesive layer 989 (optional)

[0101] The function of this layer is to bond the flexible heater 806 to the rigid substrate 868 that forms the final shape of the entire heater. Figure 8 (As shown in the image). Various types of adhesives can be used, such as pressure-activated adhesives (PAA), heat-activated adhesives (HAA), or thermosetting epoxy films (prepregs and B-stage films). It can also be a thermoplastic adhesive film that solidifies after heat and pressure are applied in a molding tool.

[0102] Another method to connect the flexible heater 806 to the support carrier 868 is to mount the heater in its final shape and directly overmold (in the form of injection molding) the carrier onto the back. In this case, layer 989 can be a material selected for molding compatibility, thereby ensuring that the plastic forming the support carrier 868 fuses to the adhesive / bonding layer 989, thus providing a strong bond between the heater and the carrier.

[0103] Now will describe the use of Figure 13 The second alternative heater arrangement of the hair styling device 1301 shown. As shown in the figure, in Figure 13 In the apparatus, each heater 1306 has eight heating regions 1367 along the length of the heater 1306 and two heating regions 1367 across the width of the heater 1306. Readers of the art will understand that the components of this embodiment are substantially the same as those described in the foregoing embodiments.

[0104] Figure 14a Two heater assemblies 1432a and 1432b are shown, which carry... Figure 13 The heaters 1306a and 1306b of the hair styling device 1301 shown. Figure 14a The orientation of the heater assemblies 1432 shown is consistent with their installation on... Figure 13The orientations are the same when the hair styling device 1301 is inside its housing. Therefore, heating assembly 1432b is shown with its hair contact surface facing downwards, while heating assembly 1432a is shown with its hair contact surface facing upwards. As can be seen from heating assembly 1432b, each heating assembly 1432 has protrusions 1436-1 and 1436-2 at each end of the assembly 1432, which hold the heating assembly 1432 in place. Figure 13 The hair styling device 1301 shown is housed within a housing 1310. It can also be seen from the heating assembly 1432b that each heating assembly 1432 has resilient feet (two in this case) 1433 on its inner surface facing the inner surface of the housing 1310. These resilient feet 1433 help allow the heating assembly 1432 to move slightly relative to the housing 1310 during use of the hair styling device 1301.

[0105] Figure 14b yes Figure 14a The longitudinal cross-sectional view of the top heater assembly 1432b shown is shown. Figure 14c This is an exploded view showing the components of each heater assembly 1432 more clearly. From Figure 14c Starting from the bottom, heater assembly 1432 includes: as referenced above Figures 9 to 11 The heater is similar to a layered heater 1406; a rigid support 1468 to which the layered heater 1406 is attached; a printed circuit board 1478 carrying a drive and processing circuit system for controlling the heater 1406; and a heater carrier 1480 for securing the heater 1406 within the housing 1310 of the hair styler. Figure 14d This is a cross-sectional view of the two heater assemblies 1432 when the user has closed the arms of the hair styling device and the hair strand 1440 is clamped between the hair contact surfaces of the two heater assemblies 1432a and 1432b. For simplicity, in Figure 14d The housing 1310 of the hair styling device 1301 is not shown in the figure.

[0106] Figure 15 This is an exploded view showing the individual layers of the layered heater 1406 used in this embodiment. As previously described, the heater 1406 is formed from multiple discrete layers mechanically or chemically bonded together. Each layer has a thickness of approximately 1 μm to 150 μm. The layers disposed in the heater 1406 are similar to those disposed in the heater 806 described above. A description of each layer is given below.

[0107] Heat dissipation layer 1582

[0108] This layer helps to dissipate heat within each heating zone 467 (some of which are in...). Figure 15(highlighted) to ensure that the temperature of each heating zone 467 can remain acceptablely uniform during typical use. As mentioned above, if the heating zone 467 is partially loaded with hair and is large enough, the unloaded portion of the heating zone 467 may generate unacceptably high temperatures, while the loaded zone will be too cold because heat cannot flow sufficiently from the hot zone to the cold zone.

[0109] In this embodiment, each heating region 467 has its own heat sink 1591, which is thermally isolated from the heat sinks of adjacent regions (existing with high thermal resistance / low thermal conductivity). This is desirable to prevent heating regions 467 from heating adjacent heating regions 467, which could increase power consumption, reduce preheating time, and complicate signal processing that depends on the power data of each region. Figure 15 As shown, the heat sink layer 1582 has sixteen heat sinks 1591-1 to 1591-16, each heat sink being formed of a material with relatively high thermal conductivity (e.g., copper). Each heat sink 1591 is physically spaced apart from its adjacent heat sink 1591, and in effect forms an island of thermally conductive material in the corresponding heating area. The heat sinks 1591 may be spaced apart from each other by a solid material having a thermal conductivity of less than 35 W / mK, or they may be spaced apart by air. The heat sinks 1591 can be formed, for example, by taking a planar layer of metal (such as a copper layer) bonded to the underlying layer and then etching the copper layer to physically separate the individual heat sinks 1591 (so that they do not contact each other). Assuming there is a break between adjacent heat sinks 1591, heat from one heating area 467 is difficult to enter the adjacent heating area 467. After the etching process has formed the gaps between adjacent heat sinks 1591, a solid material can be provided in the gaps between adjacent heat sinks 1591 by applying a coating or paint to the heat dissipation layer 1582. Alternatively, other suitable methods can be used to form the individual heat sinks 1591 that are substantially or completely physically spaced apart, and any suitable method can be used to provide solid material in the gaps between the individual heat sinks 1591.

[0110] The heat dissipation layer 1582 can provide mechanical integrity for the entire heater 1406, thus providing some protection against damage to the hair contact surface, which could otherwise expose the heater electrodes underneath, potentially leading to a short circuit or loss of function.

[0111] Dielectric isolation layer 1583

[0112] A dielectric insulating layer 1583 provides electrical insulation between the heat dissipation layer 1582 and the underlying main heater electrode layer 1584. This dielectric insulating layer 1582 will have the lowest possible thermal resistance while still meeting the dielectric requirements of the layer. This layer can be formed of polyimide, but other dielectric materials can be used. Because the layer is relatively thin, its in-plane thermal resistance is relatively high compared to its out-of-plane thermal resistance. The thermal conductivity of this layer is quite low (less than 35 W / mK). This helps prevent heat from diffusing from one heating region 467 to adjacent heating regions 467.

[0113] Main heater electrodes and sensing layer 1584

[0114] Heat is generated in layer 1584 by dissipating power from a power source (e.g., a power supply unit (PSU) or one or more batteries).

[0115] The layer 1584 includes a plurality of independently controllable heater electrodes 1664, each heater electrode defining a corresponding heating area 467. Figure 16 The form in which layer 1584 is used in this example heater 1406 is shown in more detail. As shown, in this example, there are sixteen independently controllable heater electrodes 1664-1 to 1664-16, each heater electrode defining a corresponding heating region 467. Each heater electrode 1664 is formed by a track of resistive material, the geometry (track width, thickness, length) and material of which are specified to achieve the desired resistance for a specific power supply voltage, thus providing the desired peak power to a given heating region.

[0116] Each heater electrode 1664 is formed into a meandering pattern using chemical etching as a manufacturing process (however, as mentioned above, other manufacturing processes can be used to form the heater electrode 1664). More specifically, a solid layer of conductive material is set and then etched to form different heater electrodes 1664. Figure 16The dark areas shown are the boundaries between the etched portions of layer 1584, located between the white meandering portions in the figure, which are the meandering conductor paths that form the heating electrodes 1664. In this illustrated example, adjacent heater electrodes 1664 are connected to a common positive terminal (however, in other embodiments, they may be connected to a common ground terminal) to reduce the number of electrical connections required between the drive and control board 1478 and the heater 1406. This common positive terminal connects to the different heater electrodes at vias 1665-1 through 1665-5, through which they connect to the underlying connection circuitry in layer 1590, which in turn connects to the drive and control board 1478. The other end of each heater electrode 1664 is connected to ground via a corresponding switch mounted on the drive and control board 1478 to allow independent control of the current flowing through each heater electrode 1664. As those skilled in the art will understand, having such a common positive (or ground) terminal is not necessary, and each heater electrode 1664 may be physically spaced apart from all other heater electrodes 1664, in which case each end of each heater electrode 1664 will be individually connected back to the drive and control board 1478. Figure 16 As shown, the two longitudinal edges of the layer have five protrusions extending outward from them. Eight of the ten protrusions (excluding the middle pair) contain grounding terminals for two heater electrodes 1664 that are bent around the upper surface of the rigid support substrate 1468 to connect to the drive and control board 1478.

[0117] like Figure 16 As shown, each heating electrode 1664 begins at its ground terminal and forms a meandering pattern that extends along the edge of its corresponding heating area, penetrating only a small portion of the width of the heating area. This arrangement of the heater electrodes along the edges helps to facilitate heat transfer to the center of each heating area. At the other end of the length of the heating area, it forms a meandering pattern perpendicular to the first meandering pattern, terminating at a corner of its heating area that can be found along the main axis of the layered heater 1406, where three adjacent heater electrodes 1664 converge at one of the shared vias 1665, where they connect to a shared positive terminal. Sixteen ground terminals are located on a protrusion connected to the drive and control board 1478. The meandering path located in the central region of each heating area extends along the length of the heater. This is to facilitate heat flow along this direction to address the issue of hair being only partially loaded in one area (e.g.,...). Figure 7 (As shown in the image)

[0118] The conductive material used in layer 1584 (for forming heater electrode 1664) is preferably a PTC or NTC material (e.g., stainless steel or copper), such that the resistance of heater electrode 1664 depends on its temperature, and thus the temperature of heating region 467 can be determined by measuring the parameter that varies with the resistance of the corresponding heater electrode 1664. Figure 16 The heater electrode 1664 shown can be connected to Figure 12 The circuit system shown is carried on the drive and control board 1478.

[0119] Fuse and Connector 1590

[0120] This layer 1590 carries the electric fuse for each heating zone 467 and a common positive terminal connected to the positive tail of each heater electrode 1664 via via 1665. (Example) Figure 15 As shown, each fuse is located adjacent to a corresponding heating zone in heating zone 467, and the fuses are electrically connected in series and then connected to the circuitry on the drive and control board 1478. If any heating zone 467 overheats, the corresponding fuse 1734 closest to that heating zone 467 will melt, breaking the series connection with the control board 1478. This immediately cuts off the power to all heating electrodes 1664.

[0121] Figure 17 a and Figure 17 b shows in more detail the fuse and connecting layer 1790 that carry the fuse 1734 and busbar 1735. Specifically, Figure 17 b shows a common positive terminal 1735, to which each heater electrode 1664 is connected at a via 1665. The positive terminal 1735 is defined by a protrusion extending outward from the center of one long side of the connection circuitry layer (located along the length of heater 1406). Figure 16 The center protrusion (shown as identical to the one without the grounding terminal) is connected to the drive and control board 1478. This board connection protrusion also carries the fuse circuitry connected to both ends of the drive and control board 1478.

[0122] In the case of a fused solder joint, a small amount of solder resist / solder mask will be applied in the space between the "arrows" shown in 17b. This ensures complete disconnection in the case of overheated areas by repelling molten solder.

[0123] Medium backing 1587

[0124] This layer provides electrical insulation and a connecting layer to prevent accidental exposure and moisture ingress. If desired, this dielectric layer 1587 can be thicker than the upper dielectric layer to provide enhanced structural integrity to the flexible portion of the heater 1406. Like the other dielectric layers, this dielectric layer 1587 can be a polyimide layer or can be formed from another dielectric material.

[0125] Figure 18 This illustrates how the flexible layered heater 1406 is bent over and bonded to the rigid support 1468 before and after bonding. Figures 19a to 19c The diagram illustrates forming equipment and a process for bending a layered heater 1406 over a rigid support 1468. The forming equipment includes a base 1937 and an upper extrusion section 1938 (in...). Figure 19a and Figure 19b (As shown in the diagram). The base 1937 includes a recess into which the rigid support 1468 is inserted, and the flexible heater 1406 is also inserted. The recess of the base 1937 is shaped to match the contour of the flexible heater 1406, resulting in a tight fit between the recess and the flexible heater 1406. This prevents the flexible heater 1406 from moving during the extrusion operation. The upper portion 1937 has an extrusion feature 1939 for pressing down the layered heater 1406, such that the sides and protrusions of the layered heater 1406 are pressed down and bent around the rigid support 1468, as shown in the diagram. Figure 19b As shown in the cross-sectional view, an adhesive layer can be provided between the layered heater 1406 and the rigid support 1468 to firmly bond the heater 1406 to the rigid support 1468. Once bonded, the upper extrusion portion is removed from the base 1937, and the bonded heater and rigid support sub-assembly are ready to be connected to the drive and control panel 1478 and other components constituting the heater assembly 1432 shown in FIG. 14.

[0126] In some of the above embodiments, a heat dissipation layer 982 is disposed above the heater electrodes to aid in heat dissipation within each heating area. In other embodiments, the heat dissipation layer 982 may be disposed below the heater electrode layer 984, since the heat sinks can still perform their heat dissipation function in their respective areas, regardless of whether they are above or below the heater electrode layer 984. However, positioning the heat dissipation layer 982 above the heater electrode layer (i.e., closer to the hair contact surface) can be advantageous, as this layer can provide scratch resistance to the heater 106. Heat dissipation layers may also be included both above and below the heater electrode layer(s). Figure 20 This illustrates a possible layer of a heater assembly having a heat dissipation layer 988' disposed below the heater electrode layer 984 (see above). Figure 9 As mentioned above, not all layers are required. Figure 20The reference numerals used in the figures and Figure 9 The reference numerals used for corresponding layers are the same. In this example, the heat dissipation layer 988' located below the heater electrode layer 984 includes layers mounted on... Figure 9 The heat sink and fuse on layer 988.

[0127] Figure 21a and Figure 21b The form of the optional heat dissipation layer 988' is shown in more detail. This heat dissipation layer has sixteen heat sinks 2191-1 to 2191-16. Heat sinks 2191 are formed of a thermally and electrically conductive material similar to copper. Each heat sink 2191 is electrically connected to at least one adjacent heat sink 2191 via a fuse (not shown) located between adjacent heat sinks. Dashed circle 2134 shows one of the locations where fuses are installed to electrically connect adjacent heat sinks 2191-9 and 2191-10. The heat sinks are arranged such that when the fuse (not shown) is in place, there is an electrical connection from the positive fuse connection 2136 coupled to heat sink 2191-1, through heat sinks 2191-1 to 2191-16, and back to the negative fuse connection 2138 coupled to heat sink 2191-16. If one of the heating zones overheats and the corresponding fuse connection breaks, the current path is broken, and the controller (coupled to the positive fuse connection 2136 and the negative fuse connection 2138) can detect this break in the current path (e.g., by applying a voltage across both fuse connections 2136 and 2138 and detecting the presence of current (if the fuse circuit is operating correctly) or the absence of current (meaning one or more fuses have blown)), and can take appropriate control actions, such as stopping or preventing the application of power to the heater electrodes. Figure 17 Similar to the fuse and connecting layer 1790 shown, layer 988' also includes a central busbar 2135, to which the positive tail of the heater electrode is connected via a via 2165, as shown. Figure 21b As shown by the dashed line 2165 in the figure.

[0128] In the above embodiments with heat dissipation layers, each heat sink 1091 (see...) Figure 10The heat sinks are formed as islands that do not contact adjacent heat sinks in order to minimize the ability to transfer heat from one heating area to an adjacent heating area. This helps improve the signal-to-noise ratio for sensing and independent control of different heating areas. In some embodiments, it may be desirable to provide an electrical connection between adjacent heat sinks, for example, to ground the heat sink layer. In this case, each heat sink may have some conductive material that connects them to at least some of the adjacent heat sinks. Even if an electrical connection is provided between adjacent heat sink elements, thermal disconnection or thermal decoupling will still exist between closely adjacent heat sinks as long as the connection is relatively small (e.g., less than 1 / 10 of the length / width of the heat sink). In one possible implementation, each heat sink may be electrically connected to a via 1665 / 1965 coupled to a common terminal of the heater electrode. This will prevent the accumulation of unwanted static electricity in the heat sink layer and also eliminate the impact on the heater electrode. Figure 17 The need for busbars 1735 / 2135 as shown in Figure 21 is because the connection to the electronic devices can then be made by connecting to one or more heat sinks closest to the edge of the flexible heater. However, since there is minimal physical connection between adjacent heat sinks, they can still perform the desired heat dissipation function in the respective heating areas, while minimizing heat dissipation from one area to one or more adjacent areas.

[0129] Figure 22 An exploded cross-sectional perspective view of another heater assembly is shown, with an exploded transverse cross-sectional view of heater 2206 and substrate 2268 shown on the left and a perspective view of heater 2206 and substrate 2268 shown on the right. As previously described, heater 2206 is formed of multiple discrete layers mechanically or chemically bonded together. These layers include:

[0130] Layer 2281 is a low-friction coating that also provides electrical insulation. This layer can be formed, for example, by a ceramic coating or paint, and is applied directly to the heater electrode layer 2284. Layer 2281 is designed to have a dielectric breakdown strength of 500 volts and has a strength of 9.35 × 10⁻⁶. -4 KW -1 cm 2 and 0.8 KW -1 cm 2 The thermal resistance between the layers provides the necessary electrical insulation between the hair contact surface of the heater (the upper surface of layer 2281) and the heater electrodes, while minimizing the temperature drop that occurs through the coating 2281. Minimizing the temperature drop through layer 2281 is important when the heater electrodes are used to sense temperature, as this will make the determined temperature closer to the actual temperature of the hair contact surface. A ceramic-based coating, such as Cerasol (a ceramic coating) with a thickness of approximately 30 μm to 45 μm, can provide this dielectric breakdown strength and has a strength of approximately 0.5 KW.-1 cm 2 Up to 0.6KW -1 cm 2 The thermal resistance is low. Other materials (such as aluminum nitride) can provide the required dielectric breakdown strength while offering even lower thermal resistance. For example, a 30 μm layer of aluminum nitride can provide the required dielectric breakdown strength of 500 volts and has a thermal resistance of only 9.35 × 10⁻⁶. -4 KW -1 cm 2 The thermal resistance. However, for mass-produced devices such as hair stylers, the cost of aluminum nitride layers may be too high in practice.

[0131] Layer 2284 is the heater electrode layer, which carries the heater electrodes used to heat the different heating zones of the heater. The electrodes can be formed of any suitable conductive material, but stainless steel is preferred.

[0132] Layer 2287 is an insulating layer (e.g., made of polyimide) that provides electrical insulation between electrode layer 2284 and the underlying heat-diffusing layer 2288. Polyimide is a good choice for this insulating layer 2287.

[0133] Layer 2288 is the heat dissipation layer that carries the heat sink and fuse components discussed above.

[0134] Layer 2292 is an adhesive layer for bonding the flexible heater 2206 (formed by layers 2281, 2284, 2287 and 2288) to the rigid support 2268.

[0135] Figure 23a This is a perspective view taken from above, showing the flexible heater 2206 (layers 2281, 2284, 2287 and 2288 bonded together), the adhesive layer 2292 and the rigid support 2268. Figure 23b This is a view from below of the flexible heater 2206, the adhesive layer 2292, and the rigid support 2268. Figure 23b As shown, the rigid support 2268 has honeycomb struts 2353 to provide rigidity while maintaining low weight. The rigid support 2268 also includes eight vents 2355 (the vents at the two ends are shielded by the honeycomb struts 2353). These vents are positioned relative to eight hot fuses mounted on layer 2288 of heater 2206. In this embodiment, there are sixteen heating zones, and each hot fuse provides overheat protection for two adjacent heating zones. Holes 2357 are disposed in adhesive layer 2292 surrounding the vents 2355 to ensure that the vents 2355 are not blocked by the adhesive.

[0136] Figure 24This is a plan view of independently controllable heater electrodes 2464-1 to 2464-16 on heater electrode layer 2284, which defines sixteen heating regions 467 disposed therein. Each heater electrode 2464 is formed by orbitals of resistive material, the geometry (orbit width, thickness, length) and material of which are specified to achieve a desired resistance for a specific power supply voltage, thus providing a desired peak power for a given heating region. Chemical etching can be used as a manufacturing process to form each heater electrode 2464 into a meandering pattern (however, as mentioned above, other manufacturing processes can also be used to form the heater electrodes 2464). More specifically, a solid layer of conductive material is disposed and then etched to form the different heater electrodes 2464. Figure 24 The dark areas shown are the boundaries between etched portions of the electrode layers between the white meandering sections in the attached figure, where the meandering sections serve as meandering conductor paths constituting heater electrodes 2464. In this illustrated example, each heater electrode 2464 meanders from the edge of heater 2206 to the centerline of heater 2206 and then returns to the starting edge of heater 2206 via a meandering path.

[0137] Adjacent heater electrodes 2464 share a common positive terminal (though in other embodiments they may be connected to a common ground terminal) to reduce the number of electrical connections required between the drive and control circuitry (not shown) and the heater 2206. The common positive terminal for the pairs of adjacent heater electrodes 2464 is connected back to the drive and control circuitry from the edge of the heater 2206 (described in more detail below). Therefore, in this example, a central via 1665 or busbar is not required to connect to the positive tail of the heater electrode 2464. The other end of each heater electrode 1664 is connected to ground via a corresponding switch forming part of the drive and control circuitry to allow independent control of the current flowing through each heater electrode 2464. As those skilled in the art will appreciate, having such a common positive terminal (or ground) is not necessary, and each heater electrode 2464 can be physically isolated from all other heater electrodes 1664, in which case each end of each heater electrode 2464 would be connected back to the drive and control circuitry separately. Figure 24 As shown, the electrode layer 2284 has twelve protrusions extending outward from its two longitudinal edges. These protrusions curve around the upper surface of the rigid support substrate 2268 to connect to the drive and control circuitry. Sixteen of the total twenty-four protrusions contain grounding terminals for the heater electrodes 2464, and eight protrusions contain a common positive terminal for a pair of adjacent heater electrodes 2464. Figure 24 As shown, in this example, with Figure 11 and Figure 16The example shown is different; each heater electrode 2464 does not change the direction of the meandering path at the edge portion of heater 2206.

[0138] The conductive material used in layer 2284 (for forming heater electrode 2464) is preferably a PTC or NTC material (e.g., stainless steel or copper), such that the resistance of heater electrode 2464 depends on its temperature, and therefore the temperature of heating region 467 can be determined by measuring the parameter that changes with the resistance of the corresponding heater electrode 2464.

[0139] Figure 25 The form of the heat dissipation layer 2288 used in this example is shown in more detail (viewed from below heater 2206). As shown, the heat dissipation layer 2288 comprises sixteen heat sinks 2591-1 to 2591-16, which are positioned to align with the corresponding heater electrodes 2464-1 to 2464-16. The heat sinks 2591 are formed of a thermally and electrically conductive material, such as copper. Each heat sink 2591 (except for heat sinks 2591-1 and 2591-16) is electrically connected to an adjacent heat sink at its corner portion. Each heat sink 2591 is also electrically connected to another adjacent heat sink 2591 via a fuse located between adjacent heat sinks. Dashed circle 2534 shows one of the locations where fuses are installed to electrically connect adjacent heat sinks 2591-3 and 2591-4. Heat sink 2591 is arranged such that when the fuse is in the appropriate position, there is an electrical connection (and thus a current path indicated by the dashed arrow) from the positive fuse connection 2536 connected to heat sink 2591-1, through heat sink 2591-1 to 2591-16, and back to the negative fuse connection 2538 coupled to heat sink 2591-16. If one of the heating areas overheats and the corresponding fuse connection breaks, this current path is broken, and the controller or control circuitry (coupled to the positive fuse connection 2136 and the negative fuse connection 2138) can detect this break in the current path (e.g., by applying voltage to the two fuse connections 2536 and 2538 and detecting the presence of current (the fuse circuit is operating correctly) or the absence of current (meaning one or more fuses have blown)) and can take appropriate control actions, such as stopping or preventing power from being applied to the heater electrodes. The operation of the preferred control circuitry system detecting fuse melting and taking control actions will be described in more detail later. Figure 17 Unlike the fuse and connecting layers 1790 and 2190 shown in Figure 21, layer 2288 does not include the central busbar to which the positive tail of heater electrode 2464 is connected via a via.

[0140] Figure 26a and Figure 26bThis is an enlarged perspective view of the fuse 2634 used to connect adjacent heat sinks 2591-3 and 2591-4 in this example. In this example, the fuse 2634 is formed of conductive solder material that electrically connects the adjacent heat sinks 2591-3 and 2591-4. The fuse material is located on and electrically bridges the solder resist layer 2641. Figure 26a The intact fuse is shown, allowing current to flow between adjacent heat sinks 2591-3 and 2591-4; Figure 26b This illustrates what happens when the welding material in the heating zone next to the molten wire 2634 overheats and melts. Specifically, as the welding material melts, it is repelled from the solder resist 2641 and forms droplets on the side where it will cool (once the power is removed from the heater) and solidify again. The solder resist 2641 is non-conductive, so when the welding material melts and leaves the solder resist 2641 (as... Figure 26b As shown), adjacent heat sinks 2591-3 and 2591-4 are electrically isolated from each other, thereby breaking the electrical connection between the two fuse connections 2536 and 2538. As described above, this disconnection of the electrical connection is detected by the control circuit system and is used to control (generally stop) the power supply to the heater electrode 2464.

[0141] Figure 27a and Figure 27b This is a cross-sectional view through heater 2206 (showing electrode layer 2284, insulating layer 2287, and heat sink and fuse layer 2288), adhesive layer 2292, and support member 2268, showing the arrangement of fuse 2634 and corresponding vent 2355 as described above. Specifically, Figure 27a It is a cross-sectional view when fuse 2634 is intact, and Figure 27b This is a cross-sectional view when the fuse 2634 has melted and been removed from the solder resist 2641. As those skilled in the art will understand from Figure 27, the vent 2355 prevents pressure from hot air. An air bag 2744 is provided within the support 2268 to accommodate the fuse 2634.

[0142] Drive and control circuit system

[0143] Figure 28 This is a schematic diagram showing how the heater electrodes 2464 can be connected together and connected to the drive circuit system 2823 and the power supply 2821. (See diagram below.) Figure 28As shown, each heater electrode 2464-1 to 2464-16 is connected at one end to a power supply 2821 via a main switch 2851, and at the other end to corresponding switches (in this case, MOSFET switches) 2895-1 to 2895-16. Switch 2895 is controlled by a microprocessor 2829. When heater electrode 2464 needs to provide heat, the corresponding switch 2895 closes, thereby connecting heater electrode 2464 to ground via resistor 28R. As a result, current flows from power supply 2821 to ground, causing heater electrode 2464 to heat up (when main switch 2851 is closed). The microprocessor 2829 can independently control the position of each switch 2895, allowing each heater electrode 2464 to be independently powered to reach its own desired setpoint temperature. Typically, the setpoint temperatures of the different heater electrodes 2464 will be the same.

[0144] When the temperature of the selected heating region 467 needs to be determined, the switch 2895 of the corresponding heater electrode 2464 is closed, and all other switches 2895 are opened. Thus, the selected heater electrode 2464 is connected in series with resistor 28R. Since the heater electrode 2464 is formed of PTC or NTC material, the resistance of which changes with the temperature of the heater electrode 2464, the microprocessor 2829 can determine the resistance of the selected heater electrode 2464 by measuring the voltage drop across resistor 28R (using operational amplifier 2897), and therefore determine the temperature of the corresponding heating region 467. If the determined temperature is higher than the desired temperature of the heating region 467, the microprocessor 2829 can reduce the power applied to the heater electrode 2464; or if the heating region 467 is at a temperature lower than the desired temperature, the microprocessor 2829 can increase the power applied to the corresponding heater electrode 2464. Any suitable on / off control or PWM (pulse width modulation) control can be used to change the power applied to different heater electrodes 2464. The microprocessor 2829 can sequentially select each heater electrode 2464 to determine the temperature of each heater electrode 2864 / heating region 467. Figure 28It is also shown that the voltage supplied to heater electrode 2464 can also be supplied to microprocessor 2829 (if the voltage is greater than that acceptable to microprocessor 2829, then the voltage is supplied to microprocessor 2829 via a suitable scaling or conversion circuitry system (not shown)). This voltage input allows microprocessor 2829 to regulate the drive of heater electrode 2464, for example, when powered by a battery and the battery is depleting. The voltage applied across the heater electrode may drop for other reasons, including voltage drop across the cable under high load, tolerances in the power supply output, etc. By measuring the applied voltage, microprocessor 2829 can use this information to more accurately calculate the resistance (and therefore the temperature of that heater electrode) of each heater electrode under given current circuit conditions. For example, microprocessor 2829 can use the measured voltage across resistor 28R to calculate the current flowing through heater electrode 2464 (by dividing the measured voltage across resistor 28R by the known resistance of resistor 28R). The microprocessor 2829 can then determine the resistance of the heater electrode 2464 by subtracting the voltage across resistor 28R from the sensed voltage applied to the heater electrode 2464 and dividing by the determined current. If necessary, the calculated resistance can then be equivalent to the temperature of the heater electrode 2464 using an appropriate lookup table.

[0145] The inventors have discovered that sensing the temperature of the heater electrode in the above manner requires only about 5% of the total available time, and therefore does not interfere with the power supply to the heater electrode.

[0146] Figure 28 The example also illustrates how the eight fuses 2634-1 to 2634-8 used in this example are connected to the control circuitry and how power can be automatically removed from the heater electrode 2464. Specifically, as Figure 28 As shown, the gate of the main switch 2851 is connected to the power supply via a voltage divider circuit 2856, which is connected to ground via a fuse 2634 and an optional test switch 2858. During normal operation, when the fuse 2634 is intact, the voltage at the gate of the main switch 2851 will be lower than the voltage at its source. This means the switch is closed, and current can flow from the power supply 2821 through the main switch 2851 to the heater electrode 2464. However, if one or more fuses 2634 melt and disconnect the electrical connection between the voltage divider circuit 2856 and ground, the voltage at the gate of the main switch 2851 will become the same as the voltage at the source of the main switch 2851, causing the main switch 2851 to open and thus isolating the heater electrode 2464 from the power supply 2821.

[0147] An optional test switch 2858 is configured to allow the microprocessor 2829 to test the circuitry system for faults. Specifically, the main switch 2851 may fail to enter a permanently closed position, in which case, if one or more fuses 2634 melt and disconnect to ground, the main switch 2851 will not disconnect the connection between the power supply 2821 and the heater electrode 2464. However, by configuring the test switch 2858, which can be opened and closed by the microprocessor 2829, the microprocessor 2829 can check that the main switch 2851 has not failed to enter a permanently closed state. More specifically, when the microprocessor 2829 opens the test switch 2858, this simulates the breaking of one of the fuses 2634, which should disconnect the main switch 2851. The microprocessor 2829 can then monitor the temperature of one or more heater electrodes 2464 in the manner described above (using operational amplifier 2897). If the main switch 2851 operates correctly, the temperature of the monitored heater electrode 2464, or each monitored heater electrode 2464, should decrease (because the heater has a low heat capacity, so the decrease is rapid). If, after the test switch has been opened, the temperature of any monitored heater electrode 2464 remains above the threshold temperature, the microprocessor 2829 can consider that the main switch 2851 has failed in its closed state and can open all switches 2895 to prevent further heating of the heater electrodes 2464.

[0148] like Figure 28 As shown, test switches 2858 and 2895 are n-channel MOSFETs, while the main switch 2851 is a p-channel MOSFET. The advantage of using n-channel switches is that they will enter an off state when power is removed from the control circuit, which should remove all power to the heater electrode 2464. Of course, other switches can also be used.

[0149] Heater operated by mains power

[0150] In the above embodiment, a DC power supply is used to provide power for heating the heater electrode 1664. This DC power supply is typically one or more batteries, but a DC power supply that draws power from an AC mains signal can also be used. When using DC operation, the DC voltage preferably complies with Safe Ultra-Low Voltage (SELV) regulations, which require a voltage of less than 42.4 volts. When AC power is supplied directly to the heater electrode, a thicker or more dielectric layer is typically used between the heater electrode 1664 and the hair contact surface of the hair styler.

[0151] To enable product testing facilities to test the dielectric strength of each layer, the applicant used a dielectric layer in the form of an adhesive tape, which can be peeled off for product testing. However, this dielectric tape layer is still relatively thick, meaning there is still a possibility of reducing the thickness of the dielectric layer and thus further reducing the heat capacity of the heater. Furthermore, the adhesive portion of this dielectric tape creates an undesirable thermal barrier between each dielectric layer and the hair contact surface. Therefore, a thinner dielectric layer can be provided, applied using coating, other deposition processes, or other direct bonding or forming processes. However, the inventors have recognized that this presents a challenge for testing facilities, as they can no longer peel off individual layers and test each layer separately.

[0152] The following disclosure is intended to provide a layered heater having a structure that allows a testing agency to test the dielectric properties of multiple dielectric layers of the heater.

[0153] Figure 29 An embodiment of an AC-powered multilayer heater 2906 comprising a stack of thin layers is shown. The heater 2906 includes an electrode layer 2984, a hair contact layer 2981, and dielectric layers 2983-1, 2983-2, and 2983-3, such that the electrode layer 2984 is electrically insulated from the hair contact layer 2981. Additional dielectric layers may be provided, or in some cases, only two dielectric layers may be used. As defined in the International Electrotechnical Commission (IEC) documents concerning the safety requirements for household and similar appliances, if only a single dielectric layer is used (when operating with AC mains power), it must be able to withstand (without breakdown) at least 3 kV, and if multiple dielectric layers are used, each dielectric layer must be able to withstand (without breakdown) at least 1.75 kV. As will be understood, the requirements for dielectric layers(s) as defined by the IEC or virtually by any other official entity may change over time.

[0154] Regarding layers 2981, 2984, 2983-1, 2983-2, and 2983-3, each layer typically has a first surface and a second surface, or an upper surface and a lower surface. Figure 29In the context: the lower surface of electrode layer 2984 contacts the upper surface of dielectric layer 2983-3, the lower surface of dielectric layer 2983-3 contacts the upper surface of dielectric layer 2983-2, the lower surface of dielectric layer 2983-2 contacts the upper surface of dielectric layer 2983-1, and the lower surface of dielectric layer 2983-1 contacts the upper surface of hair contact layer 2981. However, the use of the terms "upper" and "lower" does not limit the orientation of the heater, where the upper surface must always point upward. Rather, the terminology emphasizes how the layers are positioned relative to each other. In fact, since heater 2906 can be used in all forms of hair styling appliances, such as curling irons, the heater can be in any orientation, and as will be discussed in more detail below, heater 2906 can be flexible and disposed within a bending device.

[0155] The layers 2981, 2984, 2983-1, 2983-2, and 2983-3 of heater 2906 may be bonded together by an adhesive layer (pressure-set or thermosetting), by diffusion bonding of contact materials (e.g., melting them together), or other adhesive methods, defining heater 2906. This heater is designed to be very thin, with one or more dielectric layers having a total thickness of 600 micrometers or less. Hair contact layer 2981 may be a substrate on which the dielectric is formed; however, this is not mandatory, and other manufacturing methods and materials will be described later. The heater defined by layers 2981, 2984, 2983-1, 2983-2, and 2983-3 may also be flexible, and where rigidity of the heater is required, it may be provided by a rigid support to which heater 6 is attached.

[0156] Media testing

[0157] When testing the dielectric breakdown voltage of each dielectric layer, the testing facility must be able to test each dielectric layer. Therefore, reference will now be made to... Figures 30 to 32 The description describes various arrangements that allow the top surface of each dielectric layer to be accessed (directly or via the electrode layer). Each of these arrangements can be used alone or in combination with other embodiments.

[0158] exist Figure 30In the example shown, there is a hair contact layer 3081, an electrode layer 3084, and dielectric layers 3083-1, 3083-2, and 3083-3. In this embodiment, in order to be able to test the dielectric breakdown voltage of each dielectric layer 3083-1, 3083-2, and 3083-3, each dielectric layer 3083 has an exposed surface in the direction of the electrode layer 3084. In other words, a portion of the upper surface of each dielectric layer 3083-1, 3083-2, and 3083-3 does not have a layer in direct contact with it. In this case, and generally in this application, "upper" refers only to the direction from the hair contact layer 3081 to the electrode layer 3084. Figure 30 In the example shown, the exposed surfaces are positioned close to each other, and a stepped structure is formed at the edge of heater 3006. This can be done along one or more sides of the heater, or even just along a portion of a side or corner of the heater. Figure 30 The diagram illustrates a stepped structure of the dielectric layers. These exposed portions of the dielectric layers allow for testing the breakdown voltage of each dielectric layer using electrical probes. For example, the breakdown voltage of dielectric layer 3083-1 can be tested by contacting a point on the upper surface of layer 3083-1 (e.g., at point A) with one probe and another probe contacting a point on the lower surface of the hair-contact layer 3081. The voltage applied between the two probes is then increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. Similarly, the breakdown voltage of dielectric layer 3083-2 can be tested by contacting the upper surface of layer 3083-2 (e.g., at point B) with one probe and another probe contacting the upper surface of the underlying layer 3083-1 (e.g., at point A); the voltage applied between the two probes is then increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. The breakdown voltage of dielectric layer 3083-3 can be tested by contacting the upper surface of layer 3083-3 with one probe (e.g., at point C) and the upper surface of the underlying layer 3083-2 with another probe (e.g., at point B). The voltage applied between the two probes is then increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. In the case of layer 3083-3, the probes can be placed in contact with the upper surface of electrode layer 3083-3, or anywhere on the upper surface of electrode layer 3084 (since electrode layer 3084 has a relatively higher conductivity than dielectric layer 3083-3, placing the probes on electrode layer 3084 will not significantly affect the dielectric breakdown voltage of layer 3083-3).

[0159] Figure 31An example is shown that allows testing the breakdown voltage of each dielectric layer relative to the hair contact layer. Similar to the previous example, heater 3106 has a hair contact layer 3181, an electrode layer 3184, and dielectric layers 3183-1, 3183-2, and 3183-3. To measure the dielectric breakdown voltage of each dielectric layer 3183-1, 3183-2, and 3183-3, the dielectric layers are staggered such that each dielectric layer 3183 also has an exposed upper surface in the direction of the electrode layer 3184. In this example, the hair contact layer 3181 is also arranged to directly contact a portion of each dielectric layer at the location where the dielectric layer has an exposed surface. This means that the dielectric layers 3183-1, 3183-2, and 3183-3 and the hair contact layer 3181 define a stepped structure in the area to be tested. It should be noted that three dielectric layers 3183-1, 3183-2, and 3183-3 are disposed directly below the electrode layer 3184 between the dielectric layer and the hair contact layer 3181. In this example, the dielectric breakdown voltage can be tested by applying a test voltage between the upper surface of each dielectric layer 3183-1, 3183-2, and 3183-3 and the lower surface of the hair contact layer 3181. Therefore, for example, the breakdown voltage of the dielectric layer 3183-1 can be tested by contacting one probe with the upper surface of the layer 3183-1 (e.g., at point D) and another probe with a point on the lower surface of the hair contact layer 3181. The voltage applied between the two probes is then increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. Similarly, the breakdown voltage of dielectric layer 3183-2 can be tested by contacting the upper surface of layer 3183-2 with one probe (e.g., at point E) and the lower surface of hair contact layer 3181 with another probe; then the voltage applied between the two probes is increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. The breakdown voltage of dielectric layer 3183-3 can be tested by contacting the upper surface of layer 3083-3 with one probe (e.g., at point F) and the lower surface of hair contact layer 3181 with another probe; then the voltage applied between the two probes is increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. Figure 30 The example shown is different because the electrode layer 3184 is laterally displaced from the portion of the dielectric layer 3183-3 that contacts the hair contact layer 3181, so the upper surface of the dielectric layer 3183-3 cannot be tested by bringing the probe into contact with the electrode layer 3184.

[0160] Figure 32Another example is shown that each dielectric layer can be tested relative to the hair contact layer. As previously described, heater 3206 has a hair contact layer 3281, an electrode layer 3284, and dielectric layers 3283-1, 3283-2, and 3283-3. As previously described, in order to allow measurement of the dielectric breakdown voltage of each dielectric layer 3283-1, 3283-2, and 3283-3, each dielectric layer 3283 has an exposed surface in the direction of the electrode layer 3284. Dielectric layers 3283-1, 3283-2, and 3283-3 are arranged to overlap each other such that each layer has an exposed portion in direct contact with the upper surface of the hair contact layer 3281. In this embodiment, the hair contact layer 3281 has a uniform thickness, and the medium layer is arranged in two steps—one step from left to right in the figure, where medium layer 3283-3 terminates before medium layer 3283-2, and medium layer 3283-2 terminates before medium layer 3283-1; and the other step from top to bottom in the figure, where medium layer 3283-2 extends beyond medium layer 3283-1, and medium layer 3283-3 extends beyond medium layer 3283-2.

[0161] Using this arrangement, the breakdown voltage of dielectric layer 3283-1 can be tested by contacting the upper surface of layer 3283-1 with one probe (e.g., at point G) and a point on the lower surface of hair contact layer 3281 with another probe. The voltage applied between the two probes is then increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. Similarly, the breakdown voltage of dielectric layer 3283-2 can be tested by contacting the upper surface of layer 3283-2 with one probe (e.g., at point H) and a point on the lower surface of hair contact layer 3281 with another probe; the voltage applied between the two probes is then increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes. The breakdown voltage of dielectric layer 3283-3 can be tested by contacting the upper surface of layer 3283-3 with one probe (e.g., at point I) and the lower surface of hair contact layer 3281 with another probe; then the voltage applied between the two probes is increased until it exceeds a defined threshold (e.g., 1.75 kV) or until voltage breakdown occurs and current flows between the two probes.

[0162] In the above example, the dielectric layers are arranged in a stepped configuration to provide an exposed surface for testing each dielectric layer. As those skilled in the art will understand, other structures may also be provided that allow at least a portion of the top surface of each dielectric layer to be exposed. For example, one or more wells or blind holes may be provided through the dielectric layers such that one or more wells or blind holes expose the upper surfaces of all dielectric layers. For example, one well or blind hole may be provided extending downwards to the upper surface of each dielectric layer. Thus, if there are three dielectric layers, two wells or blind holes may be provided, one extending downwards to the intermediate dielectric layer and the other extending downwards to the lower dielectric layer. Alternatively, a well or blind hole may be provided having a larger outer well or hole extending downwards to the intermediate dielectric layer and a smaller well or hole extending further downwards to the upper surface of the lower dielectric layer.

[0163] Electrode layer

[0164] As those skilled in the art will understand, in Figures 29 to 32 Electrode layers 2984, 3084, 3184, and 3284 are shown schematically. The exact form of the electrodes is not important to the interpretation of this aspect of the disclosure. The electrode layers may, for example, define one or more heater elements that are heated when current passes through them. The heater elements may take the form of a zigzag track arranged on the area to be heated by the heater, or they may be defined by a bus electrode arrangement. Figure 33 a is an example of heater track 3384a, which extends in a zigzag manner across the surface of the underlying dielectric layer 3375a between two contact points 3371a and 3371b. Figure 33 b is an example of a bus electrode arrangement having two bus electrodes 3373a and 3373b electrically connected together via a conductive portion 3384b. For optimal heating, the bus electrode 3373 should span the longer sides of the rectangular conductive portion 3384b. Figure 33 As shown in b, the bus electrode and conductive component 3384b are both mounted on top of dielectric layers 3383a and 3383b. Dielectric layers 3375a and 3375b may correspond to those described above. Figures 29 to 32 The upper dielectric layer in the three-layer dielectric layer arrangement shown.

[0165] It should be noted that multiple heating elements can exist in the same electrode layer. For example, on the same electrode layer 3384, there can be multiple meandering tracks 3384a with their own contacts 3371a and 3371b and control systems, or multiple busbar-type electrode arrangements 3373 with their own control systems. In practice, a combination of meandering tracks 3384a and full-coverage tracks 3384b can be used on the same electrode layer, each track having its own control system, or a single control system that can control each electrode. When multiple heating elements are used, they can be laterally spaced from each other, such that each heating element defines a separate heating area of ​​the heater. In other words, multiple heater elements can produce their own heating areas, where each heating area has its own independently controlled heating element (as described in the above embodiments). As mentioned above, each heating element can be in the same electrode layer, which is on top of the same dielectric insulating layer on the same hair contact surface. Alternatively or additionally, each or some of the multiple heater electrodes can be disposed on a separate heater electrode layer, with a dielectric layer between the electrode layers. In any case, the heating zones can have the same or different dimensions, and the temperature of each zone can be independently controllable.

[0166] Flexible bending heater

[0167] As described above, the multilayer heater described herein is very thin and has a low heat capacity. Therefore, the heater itself is flexible, which is desirable if the heater is curved in order to heat the curved hair contact surface. Figure 34 A portion of the curved head portion of a heated hair styling device of the type of hair brush is schematically shown. This hair styling device has a curved housing 3477, an electrode layer 3464, and a top dielectric layer 3475 (two or more other dielectric layers (not shown) are also disposed between the electrode layer 3464 and the hair contact layer). The outer surface of the housing 3477 may be the hair contact layer, or the hair contact layer may be thermally connected to the housing 3477, thereby essentially making the housing an extension of the hair contact layer. The heater may be rigidly shaped into a curved form and then mounted in the housing 3477, or when mounted within the housing 3477, the flexible heater may be rigidly contained and acquire rigidity. Figure 34 The example shown depicts a meandering heater track 3464, but a busbar-type heater electrode arrangement can be used instead.

[0168] Additional (optional) layers

[0169] It is also desirable to electrically insulate the heater track from other parts of the styling device or housing (except for the hair contact surface). Therefore, a dielectric insulating layer may also be present on top of the electrode layer. Other layers or coatings may also be present on the hair contact layer to enhance certain functions of the styling device. (See above reference) Figure 9 Descriptions of several optional layers have been provided, which will not be repeated in this article.

[0170] Materials and Manufacturing

[0171] Below is a list of suitable materials and possible manufacturing processes for each material of each type of layer described above.

[0172] Hair contact layer

[0173] The hair contact layer can be made of polymers such as polyimide, polyamide, nylon, liquid crystal polymers, polyphenylene sulfide, or glass-filled polyphenylene sulfide. If they are sheet polymers, suitable manufacturing processes include hot pressing, thermoforming, lamination, CNC machining, and stamping. If they are liquid polymers, they can be manufactured by casting, extrusion molding, or liquid molding, and cured by oven curing, vacuum curing, or curing under applied stress. For liquid / resin polymers, manufacturing processes include injection molding, overmolding, resin casting, and die casting, and curing by the same process as before. The hair contact layer can also be made of ceramic materials such as silica, α-alumina, γ-alumina, κ-alumina, zirconium dioxide (zirconia), zirconium oxide-toughened alumina, aluminum nitride, magnesium aluminate, magnesium oxide (magnesium oxide), stabilized magnesia zirconium oxide, silicon nitride, and mica. These can be manufactured by ceramic molding, slurry casting, die casting, dry pressing, isostatic pressing, and extrusion, and cured by oven curing, vacuum curing, or curing under applied stress. The hair contact layer can also be made of metal, such as copper, copper alloys, copper-nickel alloys, steel, steel alloys, nickel, nickel alloys, nickel-chromium alloys, iron, iron-chromium alloys, iron-chromium-aluminum alloys, aluminum, or aluminum alloys. Such metals can be manufactured by extrusion rolling, roll forming, die forming, laser cutting, forging, CNC machining, stamping, or hydroforming.

[0174] Dielectric layer

[0175] The dielectric layer is made of polymers such as polyimide, polyamide, nylon, liquid crystal polymers, polyphenylene sulfide, or glass-filled polyphenylene sulfide. If these are sheet polymers, they can be applied by hot pressing, diffusion bonding, thermoforming, lamination, adhesive liquids, or adhesive tapes. If these are liquid polymers, they can be coated by casting, doctor blade coating (screen printing), dip coating, spin coating, spraying, or roll coating, and cured by oven curing, vacuum curing, or digital heat treatment. If they are liquid / resin polymers, they can be applied by injection molding, overmolding, resin casting, die casting, or mold coating. The dielectric layer can also be ceramic, such as silica, α-alumina, γ-alumina, κ-alumina, zirconium dioxide (zirconia), zirconium oxide-toughened alumina, aluminum nitride, magnesium aluminate, magnesium oxide (magnesium oxide), stabilized magnesia zirconium oxide, silicon nitride, or mica. If these are sheet ceramics, they can be applied by hot pressing, diffusion bonding, thermoforming, lamination, adhesive liquids, or adhesive tapes. If they are ceramic coatings, they can be applied by aerosol deposition, casting, doctor blade coating (screen printing), dip coating, spin coating, spray coating, or roll coating, and cured by oven curing, vacuum curing, or digital heat treatment. Physical vapor deposition, chemical vapor deposition, and plasma-assisted chemical vapor deposition are also possible for some materials, such as diamond-like carbon.

[0176] The dielectric layer can also be formed directly on a metal or other oxidizable substrate or hair contact layer via plasma electrolytic oxidation (PEO) or electrochemical oxidation (ECO). For example, PEO or ECO on an aluminum substrate will result in the growth of a dielectric layer of crystalline alumina.

[0177] heater track

[0178] The heater tracks in the electrode layer can be made of copper, copper alloys, copper-nickel alloys, steel, steel alloys, nickel, nickel alloys, nickel-chromium alloys, iron, iron-chromium alloys, iron-chromium-aluminum alloys, aluminum, aluminum alloys, silver, silver alloys, gold, gold alloys, carbon, or graphite. These can be manufactured by stamping, etching (including reactive ion etching, sputtering / sputter etching (ion cutting), deep reactive ion etching, isotropic wet etching, anisotropic wet etching, wet etching using dip coating, and wet etching using spin-jet methods), wire forming by wire drawing or wire extrusion, or deposition methods (e.g., physical vapor deposition, chemical vapor deposition, and plasma-assisted chemical vapor deposition). The heater tracks can also be printed using microdispensers, precise fluid distribution using valves and / or jet valve systems, thick film printing, thin film printing, or inkjet printing. Materials suitable for such printing methods include silver conductor paste, silver-palladium conductor paste, silver-platinum conductor paste, gold conductor paste, platinum conductor paste, copper conductor paste, carbon conductor paste, and graphite conductor paste. The heater track can also be made of ceramic, such as molybdenum disilicide, silicon carbide, barium titanate, or lead titanate. These materials can be manufactured by ceramic molding, slurry casting, die casting, dry pressing, isostatic pressing, or extrusion, and can be cured by oven curing, vacuum curing, or curing under applied stress.

[0179] busbar

[0180] The busbars required for the full-coverage heater element can be made of copper, copper alloys, copper-nickel alloys, steel, steel alloys, nickel, nickel alloys, nickel-chromium alloys, iron, iron-chromium alloys, iron-chromium-aluminum alloys, aluminum, aluminum alloys, silver, silver alloys, gold, gold alloys, carbon, or graphite. These can be manufactured by: stamping, etching (including reactive ion etching, sputtering / sputtering etching (ion cutting), deep reactive ion etching, isotropic wet etching, anisotropic wet etching, wet etching using dip coating, and wet etching using spin-jet methods), wire forming by wire drawing or wire extrusion, or deposition methods (e.g., physical vapor deposition, chemical vapor deposition, and plasma-assisted chemical vapor deposition). The busbars can also be printed using microdistributors, precise fluid distribution using valves and / or jet valve systems, thick film printing, thin film printing, or inkjet printing. Materials suitable for such printing methods include silver conductor paste, silver-palladium conductor paste, silver-platinum conductor paste, gold conductor paste, platinum conductor paste, copper conductor paste, carbon conductor paste, and graphite conductor paste.

[0181] To manufacture a multilayer heater with a stepped structure, various manufacturing methods as described above can be used. Specifically, to manufacture layers of different sizes, it may be convenient to use masking techniques, positive masks, or negative masks to produce the stepped structure or other structures required for manufacturing a multilayer heater having multiple dielectric layers including an exposed top surface.

[0182] Another technique commonly used in manufacturing multilayer heaters is in-mold electronics (IME) fabrication. This process involves assembling layers within a mold (i.e., around the edges of the mold, with spaces in the middle of the mold) and injecting material into the mold to fill the gaps.

[0183] Hair cooling

[0184] Referring to the hair styler 3501 shown in Figure 35, when hot-styling hair, the process of cooling the hair after it has been heated can be very important for improving the styling. If the hair is cooled while maintaining the curl, the curl compression (the tightness of the curl retained) is found to be improved. For all styling types, not just curls, hair generally holds its style better when cooled to the desired look. For example, a user can use a hair straightening tool such as styler 3501 to curl the hair by wrapping it around one arm 3504a of styler 3501, passing the hair through a heater 3506a (which can be any of the heaters mentioned above), and then passing styler 3501 over the hair strand. This... Figure 36 As shown in the figure, Figure 36 The illustration shows a user using a stylist 3501 to curl a section of hair 3640. The hair section 3640 is wrapped around the stylist 3501 such that it contacts the housings 3502a and 3502b of each arm, and also contacts the heaters 3506a and 3506b of each arm when the stylist 3501 is closed. By moving the stylist 3501 through the hair section 3640 in this position, the hair passes between the heaters 3506a, 3506b and through the housings 3502a, 3502b, thus curling the hair. If the housings 3502a, 3502b of the stylist 3501 cool the hair 3640, a tighter (and generally more durable) curl can be achieved because the hair is cooled while in the curled position. This is referred to as improved curl compression.

[0185] For hair stylers with conventional heaters (i.e., ceramic heating plates), heat typically leaks into surrounding components (e.g., the case) due to its heating properties and the nature of the materials. This means that when a user curls their hair, the case is usually already slightly heated, and the temperature of the hair often further increases the temperature of the case. This results in suboptimal curls. Conventional heater technology also fills the space inside the styler's casework, making it difficult to include any cooling components without making the styler too large. In contrast, compared to conventional heating technologies, firstly, the extremely low heat capacity heater 3506, as described above, results in a much lower level of heat leakage into the surrounding casework. Secondly, the extremely low heat capacity heater 3506 occupies less space within the casework, which also facilitates the installation of active cooling components. This is useful because although the heater 3506 heats the casework to a degree lower than a conventional ceramic heater could possibly reach, the heat from the hair itself can cause the temperature of the casework to increase. Therefore, active cooling components can be incorporated within the styler 3501 to promote cooling of the hair in addition to heating.

[0186] Fan cooling

[0187] Figure 35a and Figure 35b Schematic side and perspective views of an embodiment of a stylist 3501 including an active cooling component are shown. Specifically, each includes heaters 3506a and 3506b and two arms 3504a and 3504b of housings 3502a and 3502b, connected via and movable relative to a shoulder 3503, within which a fan cooling mechanism is disposed. A small fan circulates air within the housings 3502a and 3502b, thereby actively cooling the housings through heat exchange. The fan causes air to flow from the shoulder 3503 along at least one of the arms 3504a and 3504b of the stylist 3501, but typically along both arms. In some embodiments, the air flows entirely within the housings 3502a and 3502b, while in other embodiments, the air flows out of the housings 3502a and 3502b.

[0188] Figure 37A schematic perspective view of one arm 3504a of the molding device is shown, with the end of arm 3504a removed to show the internal components within the housing 3502a below the thin heater 3506a. Directly below the heater 3506a is a carrier 3768 for supporting the heater 3506a. Below and connected to the carrier 100 is a structure arranged to support the heater 3506a and the carrier 3768 while still allowing air to flow within the housing 3502a. This structure has an open design, including resilient feet 3733 at the bottom of the carrier 3768 that contact the housing 3502a to allow slight movement of the heater 3506a relative to the housing 3502a. The structure also includes protrusions 3736 at each end of the carrier 3768 that engage with the housing 3502a to hold the heater 3506a and the carrier 3768 in place within the arm 3504a. The cavity 3779 in which air can flow is adjacent to most of the surface area of ​​the outer casing 3502a.

[0189] Figure 38a and Figure 38b An exemplary embodiment of a fan cooling arrangement is shown, wherein air from the fan is used to cool the housing via a heat exchange cooling mechanism. Figure 38a A schematic perspective view of the entire mold 3501 is shown, in which the ends of the housing are removed so that the internal components within the housings 3502a and 3502b can be seen. Figure 38b An enlarged view of the open end of an arm 3504a is shown, revealing the internal components within a housing 3502a. As described above, this arrangement includes a carrier 3768 and a support structure comprising resilient legs 3733 and protrusions 3736. Furthermore, the housing 3502a includes inwardly projecting ribs 3893 disposed on its inner surface. The ribs 3893 extend parallel to the length of the arm 3504a and guide airflow from a fan located within the shoulder 3503 along the length of the housing 3502a. The ribs 3893 can contribute to a smooth airflow within the cavity 3779. This improves the efficiency of airflow over the surface of the housing 3502a and heat removal. The ribs 3893 also increase the surface area over which air can flow over the housing 3502a, thereby cooling the housing 3502a through a heat exchange cooling effect.

[0190] Figure 39a and Figure 39b An alternative mechanism is shown in which air from a fan is used to directly cool the hair. Figure 39a A schematic perspective view of the stylist 3501 is shown, in which heaters 3506a, 3506b are provided on each arm 3504a, 3504b and a fan is provided in the shoulder 3503. Figure 39bAn enlarged perspective view of the arm is shown, with its ends removed to reveal the internal components within the housing 3502a. In the aforementioned embodiment, the internal components include a carrier 3768 located below the heater 3506a, and a support structure including resilient legs 3733 and protrusions 3736. In this embodiment, the housing 3502a includes an opening 3996 that facilitates airflow from the cavity 108 within the housing 3502a to the exterior of the housing 3502a. This airflow can thus directly cool the hair located on the outer surface of the housing 3502a. The opening 3996 shown is formed as an elongated slot extending parallel to the length of the arm 3504a of the stylist 3501. However, other arrangements and configurations may also be used.

[0191] The cooling level can be changed by altering the fan flow rate. This can be adjusted based on the temperature of heater 3506, which can be a desired setpoint temperature, a measured temperature (such as that measured by temperature measurement circuitry 225), and / or based on the heat load of heater 3506.

[0192] Liquid cooling

[0193] In an alternative embodiment, cooling can be achieved using a fluid-based heat exchange cooling mechanism. In this embodiment, a fluid-containing conduit is positioned adjacent to the housing 3502 such that it can be cooled by the liquid via the heat exchange mechanism. The conduit is fluidly sealed to prevent leakage of fluid from the molder 3501 or onto internal components. The fluid can be water or a dedicated coolant fluid. The conduit can be configured such that it covers a continuous diffusion across the inner surface of the housing 3502, or it can be arranged as a series of conduits passing through the inner surface of the housing 3502 (these conduits can be connected to effectively form a long conduit extending serpentinely on the inner surface), or essentially an alternative arrangement. Pumps and / or agitators can be additionally (and optionally) provided to enhance the flow of fluid through (one or more) the conduits.

[0194] For airflow cooling systems, the cooling effect can be altered by increasing the fluid flow through the duct, for example, by changing the settings of the pump and / or agitator. This can be done based on the heater setpoint temperature, the measured temperature, and / or the heat load on the heater.

[0195] Thermoelectric cooling

[0196] In another embodiment, a thermoelectric cooling system can be used to cool the housing 3502. This is in Figure 40 As shown in the figure, Figure 40A schematic perspective view of the arm 3504a of the molding tool is shown, with its end removed to reveal the internal components. In the aforementioned embodiment, the internal components include a carrier 3768 located below the heater 3506a, and a support structure including resilient legs 3733 and protrusions 3736. Additionally, a thermoelectric cooling system 4098 is provided on the inner surface of the housing 3502. This is configured to function as a solid-state heat exchanger to cool the housing 3502 via thermoelectric cooling. Figure 40 As shown, the thermoelectric cooling system 4098 can be arranged such that it spans the available inner surface area of ​​the housing 3502. However, alternative arrangements of thermoelectric coolers can be used, such as those in a patterned configuration.

[0197] Thermoelectric cooling systems offer the advantage of excellent control over cooling (i.e., cooling temperature). Therefore, cooling can be controlled, for example, based on the temperature of heater 3506 (based on the desired operating temperature, heat load, and / or measurements taken by the temperature measurement circuitry 225). Furthermore, since thermoelectric coolers can be manufactured in a very small size, an array of thermoelectric coolers can be arranged within housing 3502. Each cooler in the array can be arranged to correspond to one or more heating zones of heater 3506a. This allows cooling to be defined according to the load on each heating zone. For example, a lower cooling temperature can be used when it is determined that an adjacent heating zone is loaded with hair.

[0198] The housings 3502a and 3502b include an opening 3996 (e.g. Figure 39a and Figure 39b In some embodiments of the styling device 3501 (shown), styling product can be dispensed through opening 3996 while the user styles their hair. This styling product can be, for example, hairspray or hair gel that can be used to help with styling. In this embodiment, the styling device 3501 may include a reservoir for containing the product and / or may be configured to contain a cartridge containing the hair product. The styling device 3501 may then be further configured to disperse the product into a mist.

[0199] The cooling mechanism has been described above with reference to a hair straightening appliance that includes two arms; however, active cooling mechanisms such as those described above can also be implemented in other hair drying and styling appliances. For example, a curling iron may include a heating section and a cooling section.

[0200] Cooling can be achieved based on the heating of the heater; for example, a specific combination of heating and cooling temperatures can be used. In some implementations, the user can select this combination. Alternatively, the combination can be predefined for each heating temperature.

[0201] Additionally, the very thin nature of the heaters allows the heaters and cooling zones to be positioned very close to each other and / or, in some embodiments, the heaters themselves are cooled by a cooling system. Because the heaters have very low heat capacity, they can cool very quickly and then undergo active cooling that is transferred to the hair. This facilitates heating and cooling the hair with the same or adjacent portions of the styler.

[0202] Electrical connection with heater

[0203] As described above, the drive and control circuitry is typically mounted on a printed circuit board (PCB) and requires connection between the PCB and the tail of the heater electrodes and fuse circuitry. Figure 14 shows an example where PCB 1478 is mounted below heater support 1468, and the tail of the electrodes and fuse circuitry is bent behind heater support 1468. The conductive layer on the PCB is made of copper, and as described above, the conductive tracks constituting the heater electrodes are preferably made of stainless steel. The connection formed between the copper on the PCB and the stainless steel on the heater needs to provide a reliable and consistent connection over a temperature range of 10°C to 150°C. The applicant has attempted direct soldering or using FFC-type connectors to connect to the heater tracks. However, soldering to stainless steel is not easily mass-produced. The acid-based soldering flux used is highly toxic and, without adequate protection, may cause the flexible heater 1406 to delaminate from heater support 1468. Furthermore, welded joints are subject to thermal fatigue, leading to cracking and potential failure over time, especially when welded to the flexible heater 1406 (the hottest component in the assembly). While FFC connectors are simpler, they are too expensive for mass-produced products such as hair styling devices.

[0204] Therefore, the applicant has developed a simpler and cheaper method for establishing electrical continuity between the stainless steel terminals of the flexible heater 1406 and the copper terminals on the rigid PCB 1478. This requires the use of spring clips to establish a direct mechanical connection between the terminals on the flexible heater 1406 and the terminals on the rigid PCB 1478, which maintains a consistent electrical contact resistance between the two components as they expand and contract due to temperature changes.

[0205] Figure 41a The above reference is shown in use. Figure 18 Or, as shown in Figure 19, before forming the flexible heater 4106 above the upper surface of the heater support 4168, the heater 4106 (which can be any of the aforementioned multilayer flexible heaters) is located on the upper surface of the heater support 4168. Once formed, the resulting assembly (such as...) Figure 41b(As shown) A flexible heater 4106 folded beneath a heater support 4168 has connecting protrusions 4150-1 and 4150-2 (carrying terminals of the heater electrodes and a fusible circuit system). The connecting protrusions 4150 are preferably adhered to the underside of the heater support 4168. A rigid PCB 4178 (carrying a drive and control circuit system) has multiple surface-mount spring clips 4152, each for each electrical connection formed between the circuit system on the rigid PCB 4178 and the terminals of the heater electrodes and the fusible circuit system located on the connecting protrusions 4150. The rigid PCB 4178 with the spring clips 4152 is then attached to the bottom of the heater support 4168 (e.g., Figure 41c As shown), the spring clip 4152 is aligned and contacts the corresponding terminal on the connecting protrusion 4150. The rigid PCB can be attached to the heater support 4168 using screws, clamps, friction fits, etc. The attachment of the rigid PCB 4178 preferably involves partially compressing the spring clip 4152 (e.g., ...). Figure 41d As shown), this allows them to absorb any dimensional changes (tolerances between sheets, or thermal expansion and contraction) while maintaining consistent contact pressure (and thus contact resistance) on the terminals of the heater electrodes and the fusible circuit system. Preferably, entry protection is provided around the rigid PCB and spring clips to prevent dust or liquids from affecting the stability of the contact.

[0206] As shown in Figure 42c and Figure 41d As shown, the spring clip has a generally "V" shape and is made of a conductive material (such as steel). The shape and thickness of the material forming the spring clip 4152 provide the spring clip 4152 with "elasticity" or resilience. Of course, other shapes of spring clips 4152 can be used.

[0207] Using this spring clip 4152 offers many advantages: They are an order of magnitude cheaper than FCC connectors; They are easy to incorporate into mass-produced products, such as hair stylers, because they can be “picked up and placed” onto a rigid PCB using solder paste (post-processing in the reflow oven ensures reliable contact between the rigid clip and the terminals on the rigid PCB). The components on the rigid PCB have a unique solder joint, providing some isolation between the heat-generating heater 4106 and the solder (which helps extend lifespan). The flexibility of the spring clip 4152 should absorb dimensional changes caused by the thermal expansion and contraction of the rest of the assembly; and Assuming no dust or moisture enters, the spring clip 4152 should maintain a constant force connection within the temperature range, thereby maintaining a constant contact resistance.

[0208] Modify and replace

[0209] Detailed embodiments and some possible alternatives have been described above. As those skilled in the art will understand, many modifications and further substitutions can be made to the above embodiments while still benefiting from the invention embodied therein. Therefore, it should be understood that the invention is not limited to the described embodiments, but includes modifications that are obvious to those skilled in the art and fall within the scope of the appended claims.

[0210] The invention has been described above by way of implementation in a hair straightening device (“straightener”) employing a flat hair styling heater 106. However, the invention can alternatively be implemented in any form of hair styling device, such as (but not limited to) curling irons, hair clips, or hot brushes. The heater 6 may define a flat, curved, ridged, or barrel-shaped heating surface. The hair styling device may have two arms similar to the device shown in FIG. 1, or it may be a single-arm device. The aforementioned heater can also be used in hair dryers or combination devices that use conductive heating and air to dry and style a user’s hair (e.g., those described in the applicant’s earlier PCT application WO 2021 / 019239). In embodiments using air, the heater 106 may be perforated, allowing air to pass through and be heated by the heater as it passes through.

[0211] In the above embodiments, a metal-oxide-semiconductor field-effect transistor (MOSFET) switch is used to control the power supply and sensing of the heater electrodes. As those skilled in the art will understand, other switches may be used alternatively. For example, a field-effect transistor (FET), such as a gallium nitride FET or a bipolar junction transistor (BJT), may be used.

[0212] In the example above, the heater electrodes are described as following a meandering path. As those skilled in the art will understand, the use of the term "meandering" is intended to encompass any path within the heating region, which can be a tortuous path, thereby achieving the desired resistance within the heating region while maintaining a consistent current density as much as possible. The path can be designed to have a substantially uniform thickness in both the width (and depth) directions in order to maintain a consistent current density, thereby reducing the occurrence of hot spots.

[0213] In the above example, a heat dissipation layer is provided, which has individual heat sinks corresponding to the individual heater electrodes disposed in the heater electrode layer. As those skilled in the art will understand, this is not necessary. In the example where the heater electrodes are arranged in side-by-side rows of heater electrodes (each heater electrode extends along the length of the heater) (e.g., as...), Figure 13 (Those shown), a heat sink can be set for the heater electrodes in each row.

[0214] In the preferred control circuit system described above, a fuse is coupled between the main switch and a reference potential (ground). As those skilled in circuit design will understand, the fuse can be coupled to the main switch in several different ways. For example, the fuse can be coupled between a power supply reference potential (e.g., 5V) and the control gate of a control switch, the output of which is connected to the control gate of the main switch. In this case, when one of the fuses melts, this disconnects the control switch from the reference potential, causing the control switch to change state, which in turn causes the main switch to change state, thereby preventing the supply of power to one or more of the heater electrodes. Of course, other arrangements are also possible.

[0215] In the preferred heater arrangement described above, eight fuses are provided to protect sixteen heating zones. As those skilled in the art will understand, one fuse can be provided for each heating zone, or in practice, one fuse can be provided for three or more heating zones. Since the heating zones are arranged along the length and width of the heater, providing one fuse for four heating zones will work well.

[0216] Throughout the description and claims of this specification, the words “comprising” and “including”, as well as variations thereof, mean “including but not limited to” and are not intended to exclude other components, integrals or steps.

[0217] As used in this disclosure, expressions such as "to dry hair" or "reducing the moisture content of hair" can refer to the removal of "unbound" water that is present on the outside of the hair when it is wet, or the removal of "bound" water that is present inside each hair and can interact with it during heat styling. When drying hair, it is not necessary to remove "bound" water, but some removal of bound water may occur during the drying or styling process.

[0218] Various other modifications will be obvious to those skilled in the art and will not be described in further detail here.

[0219] Various examples have been described above. The following numbered clauses summarize one or more aspects of some of those examples:

[0220] Aspect 1

[0221] 1. A hair drying and / or styling appliance comprising a multi-layer heater, said multi-layer heater comprising a plurality of layers bonded together, wherein said multi-layer heater comprises: Hair contact layer; A heater electrode layer comprising heater electrodes formed of a conductive material, wherein heat is generated when an electric current passes through the heater electrodes; and A plurality of dielectric layers are interposed between the heater electrode layer and the hair contact layer, wherein at least one dielectric layer is in contact with the heater electrode layer, and at least a portion of each dielectric layer that is not in contact with the heater electrode layer is exposed in the direction of the heater electrode layer.

[0222] 2. The appliance according to Clause 1, wherein the plurality of dielectric layers form a stepped structure.

[0223] 3. The appliance according to clause 1 or 2, wherein the hair contact layer forms a stepped structure.

[0224] 4. The appliance according to any one of the preceding clauses, wherein at least a portion of each medium layer is in contact with the hair contact layer.

[0225] 5. The appliance according to any one of the preceding clauses, wherein the hair contact layer further comprises a coating.

[0226] 6. The appliance according to any one of the preceding clauses, wherein at least a portion of the hair contact surface is flat, curved, and / or ribbed.

[0227] 7. The appliance according to any one of the preceding clauses, wherein at least a portion of the multilayer heater is flexible.

[0228] 8. The appliance according to Clause 7, wherein the multilayer heater is contained within a curved housing.

[0229] 9. The appliance according to any one of the preceding clauses, wherein the heater electrode layer comprises one or more heater elements.

[0230] 10. The appliance according to Clause 9, wherein each of the one or more heater elements includes a meandering heater track with a heater track contact point provided at either end of the meandering track, or wherein the heater element includes a bus heater arrangement having a pair of bus electrodes and a conductive portion extending between the bus electrodes.

[0231] 11. The appliance according to any one of clauses 9 or 10, wherein the heater electrode layer comprises a plurality of independently powered heater elements that define corresponding plurality of heating regions on the heating surface of the multilayer heater.

[0232] 12. The appliance according to any one of the preceding clauses, wherein the plurality of dielectric layers have a total thickness of less than 0.6 mm.

[0233] 13. The appliance according to any one of the preceding clauses, wherein each of the plurality of dielectric layers has a dielectric breakdown voltage greater than 1.75 kV at a leakage current of 100 mA.

[0234] 14. The appliance according to any one of the preceding clauses, wherein at least one dielectric layer is directly bonded to at least one of the hair contact layer, another dielectric layer of the plurality of dielectric layers, or the heater electrode layer.

[0235] 15. The appliance according to any one of the preceding clauses, wherein the multilayer heater is flexible and mounted to a rigid support, wherein the ends of one or more heater electrodes are disposed on at least one connecting protrusion folded under the rigid support.

[0236] 16. The appliance according to Clause 15, wherein a rigid circuit board is disposed below the rigid support, and wherein a plurality of spring clips are disposed for forming an electrical connection between terminals on the rigid circuit board and terminals of the one or more heater electrodes disposed on the connecting protrusion.

[0237] 17. A method of manufacturing a hair drying and / or styling appliance having a multi-layer heater, the multi-layer heater comprising a plurality of layers bonded together, wherein the method comprises: Set a hair contact layer; A heater electrode layer is provided, comprising heater electrodes formed of a conductive material, which generate heat when current passes through them; and Multiple dielectric layers are inserted between the heater electrode layer and the hair contact layer, such that at least one dielectric layer is in contact with the heater electrode layer, and The dielectric layers are arranged such that at least a portion of each dielectric layer that does not contact the heater electrode layer is exposed in the direction of the heater electrode layer.

[0238] Aspect 2

[0239] 1. A hair drying and / or styling appliance, comprising: Heater, which is used to provide heat to dry hair and / or style hair; The outer casing; and Cooling components; The heater is a multi-layer heater comprising multiple functional layers bonded together, wherein the multi-layer heater is installed within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater comprises: A heater electrode layer comprising one or more heater electrodes formed of a conductive material, wherein the one or more heater electrodes generate heat when an electric current passes through them; and At least one upper dielectric layer is located above the heater electrode layer to electrically isolate the heater electrode layer; The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 30 μm and 2 mm; and The cooling component is configured to actively cool the housing during molding.

[0240] 2. The appliance according to Clause 1, wherein the housing is arranged to at least partially surround the heater.

[0241] 3. The appliance according to clause 1 or 2, wherein the housing is arranged to support the heater.

[0242] 4. The appliance according to any of the preceding clauses, wherein the heater is disposed on a first surface of the appliance, and the housing is located on at least one other surface of the appliance.

[0243] 5. The appliance according to any of the preceding clauses, wherein the appliance includes an arm, and both the heater and the housing are disposed on the arm; preferably, wherein the heater is disposed on a first surface of the arm, and the housing is located on at least one other surface of the appliance.

[0244] 6. The appliance according to any of the preceding clauses, wherein the cooling component is configured to cool the housing via heat exchange.

[0245] 7. The appliance according to any of the preceding clauses, wherein the cooling component includes fluid within a conduit adjacent to the inner surface of the housing.

[0246] 8. The appliance according to any of the preceding clauses, wherein the cooling component includes a fan device for moving gas, preferably wherein the gas is air.

[0247] 9. The appliance according to Clause 8, wherein the appliance comprises two arms connected by a shoulder, and wherein the fan is disposed in the shoulder and configured to move gas along one or both of the arms.

[0248] 10. The appliance according to clause 8 or 9, wherein the fan device is configured to move gas within the inner cavity of the housing.

[0249] 11. The appliance according to Clause 10, wherein the housing includes an opening arranged to allow air to flow from the interior of the housing to the exterior of the housing.

[0250] 12. The appliance according to Clause 11, wherein the opening is formed as a slot, preferably wherein the slot is arranged parallel to the length of the appliance, more preferably parallel to the length of the arm of the appliance.

[0251] 13. The appliance according to any one of clauses 8 to 12 further includes ribs projecting from the surface of the housing, preferably projecting radially inward from the inner surface of the housing.

[0252] 14. The appliance according to Clause 13, wherein the rib is arranged such that the rib extends in a direction parallel to the length of the appliance, preferably parallel to the length of the arm of the appliance.

[0253] 15. The appliance according to Clause 7, wherein the fluid is a liquid, preferably a coolant.

[0254] 16. The appliance according to any of the preceding clauses, wherein the cooling component comprises a thermoelectric cooling element.

[0255] 17. The appliance according to any of the preceding clauses further includes at least one support within the housing to support the heater, preferably wherein the support is arranged to stabilize the heater relative to or within the cavity of the housing.

[0256] 18. The appliance according to any of the preceding clauses, wherein the heater comprises a plurality of independently controllable heating zones, and preferably wherein the cooling component comprises a plurality of independently controllable cooling zones.

[0257] 19. The appliance according to any of the preceding clauses, wherein the combined thermal conductivity of the multilayer heater in a plane perpendicular to the thickness is less than 15 W / mK and greater than 0.1 W / mK.

[0258] 20. The appliance according to any one of the preceding clauses, wherein the multilayer heater is flexible and mounted to a rigid support, wherein the ends of one or more heater electrodes are disposed on at least one connecting protrusion folded under the rigid support.

[0259] 21. The appliance according to clause 20, wherein a rigid circuit board is disposed below the rigid support, and wherein a plurality of spring clips are disposed for forming an electrical connection between terminals on the rigid circuit board and terminals of the one or more heater electrodes disposed on the connecting protrusion.

[0260] 22. A method of operating a hair drying and / or styling appliance, the appliance comprising a heater configured to heat hair for styling, the heater being disposed within a housing, wherein the method comprises heating the heater while cooling the housing.

[0261] 23. The method according to Clause 22, wherein cooling the housing includes operating an active heat exchange mechanism, the active heat exchange mechanism preferably disposed inside the appliance.

[0262] 24. The method according to Clause 23, wherein the active heat exchange mechanism comprises at least one of: a fan for promoting gas flow, said gas preferably air; a liquid cooling system; and a thermoelectric cooling system.

[0263] 25. The method according to any one of clauses 22 to 24 further includes directly cooling the hair by promoting the flow of gas, preferably air, out of the housing.

[0264] 26. The method according to any one of Clauses 22 to 25, wherein the hair drying and / or styling appliance is a hair drying and / or styling appliance according to any one of Clauses 1 to 21.

[0265] 27. A computer program product comprising computer-implementable instructions for causing a programmable device to perform a method according to any one of clauses 22 to 26.

[0266] Aspect 3

[0267] 1. A hair drying and / or styling appliance comprising a multi-layer heater having multiple functional layers bonded together, wherein the multi-layer heater is mounted within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater comprises: A heater electrode layer comprising one or more heater electrodes formed of a conductive material, wherein the one or more heater electrodes generate heat when an electric current passes through them; and At least one upper dielectric layer is located above the heater electrode layer to electrically isolate the heater electrode layer; The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 30 μm and 2 mm; and The combined thermal conductivity of the multilayer heater in a plane perpendicular to the thickness is less than 300 W / mK and greater than 15 W / mK.

[0268] 2. The appliance according to Clause 1 includes a fan for generating an airflow that passes through or through an opening in the multilayer heater and is heated by the multilayer heater.

[0269] 3. The appliance according to any one of clauses 1 or 2, wherein the heater has a strength greater than 2 W / cm². 2 And less than 100 W / cm 2 Preferably greater than 8 W / cm 2 The power density.

[0270] 4. The appliance according to any one of clauses 1 to 3, wherein the heater electrode layer comprises a plurality of independently powered heater electrodes defining corresponding plurality of heating regions on the heating surface of the multilayer heater.

[0271] 5. The appliance according to Clause 4, wherein the combined thermal conductivity of the multilayer heater in the plane perpendicular to the thickness is measured along a line passing through adjacent heating regions.

[0272] 6. The appliance according to clause 4 or 5, wherein the maximum size of each heating zone depends on the power density of the multilayer heater, the thickness of the multilayer heater, and the lateral conductivity of the multilayer heater.

[0273] 7. The appliance according to Clause 6, wherein, in the case where hair is partially loaded in the heating area, the maximum size of each heating area also depends on the maximum permissible temperature difference between different portions of the heating area.

[0274] 8. The appliance according to any one of clauses 4 to 7, wherein the multilayer heater further comprises at least one heat dissipation layer disposed above the upper dielectric layer and / or below the heater electrode layer, the heat dissipation layer comprising a plurality of heat sinks that regularize the heating provided in the heating area.

[0275] 9. The appliance according to Clause 8, wherein each radiator is formed as an island that does not contact adjacent radiators to reduce heat diffusion from one heating area to adjacent heating areas.

[0276] 10. The appliance according to clause 8 or 9, wherein each radiator is formed of metal.

[0277] 11. The appliance according to any one of clauses 8 to 10, wherein the heat sinks are isolated from each other in a plane perpendicular to the thickness by a solid or semi-solid material having a thermal conductivity of less than 35 W / mK, and most preferably less than 0.3 W / mK.

[0278] 12. The appliance according to any one of clauses 1 to 11, wherein the individual layers of the multilayer heater are bonded together to have a peel strength of at least 0.35 Newtons / mm.

[0279] 13. The appliance according to any one of clauses 1 to 12, wherein the multilayer heater further comprises one or more of the following: i) A low-friction coating, the upper surface of which provides a hair contact surface for the multilayer heater; ii) A lower dielectric layer disposed below the heater electrode layer; and iii) An auxiliary heater electrode layer, comprising one or more heater electrodes disposed below the heater electrode layer and a dielectric layer disposed between the heater electrode layer and the auxiliary heater electrode layer.

[0280] 14. The appliance according to any one of clauses 1 to 13, wherein one or more layers of the multilayer heater are bonded together using an adhesive, a thermal bond, a physical vapor deposition, a screen printing, or another coating process.

[0281] 15. The appliance according to any one of clauses 1 to 14, wherein one or more of the media layers comprise polyimide.

[0282] 16. The appliance according to any one of clauses 1 to 15, wherein the multilayer heater is flexible and bonded to a rigid structure to provide rigidity to the multilayer heater.

[0283] 17. The appliance according to any one of clauses 1 to 16, wherein the multilayer heater has a flat, curved and / or ribbed heating surface.

[0284] 18. The appliance according to any one of clauses 1 to 17, wherein the multilayer heater provides a flat heating surface and has curved edges that provide a curved heating surface.

[0285] 19. The appliance according to any one of clauses 1 to 18 further includes a controller configured to control the application of electricity to the multilayer heater to control the heat generated by the multilayer heater.

[0286] 20. The appliance according to any one of clauses 1 to 19, wherein the appliance is a single-arm or double-arm device.

[0287] 21. The appliance according to any one of the preceding clauses, wherein the multilayer heater is flexible and mounted to a rigid support, wherein the ends of one or more heater electrodes are disposed on at least one connecting protrusion folded under the rigid support.

[0288] 22. The appliance according to clause 21, wherein a rigid circuit board is disposed below the rigid support, and wherein a plurality of spring clips are disposed for forming an electrical connection between terminals on the rigid circuit board and terminals of the one or more heater electrodes disposed on the connecting protrusion.

[0289] 23. A method for manufacturing a hair drying and / or styling appliance, the method comprising: A multi-layer heater with multiple functional layers bonded together is provided; The multi-layer heater is installed within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater is configured as follows: A heater electrode layer is provided, comprising one or more heater electrodes formed of a conductive material, which generate heat when current passes through them; and At least one upper dielectric layer is provided above the heater electrode layer to electrically isolate the heater electrode layer from the hair contact surface; The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 30 μm and 2 mm; and The combined thermal conductivity of the multilayer heater in a plane perpendicular to the thickness is less than 300 W / mK and greater than 15 W / mK.

[0290] Aspect 4

[0291] 1. A hair drying and / or styling appliance comprising a multi-layer heater having multiple functional layers bonded together, wherein the multi-layer heater is mounted within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction. The multilayer heater includes: A heater electrode layer comprising a plurality of independently powered heater electrodes formed of a conductive material, wherein the plurality of heater electrodes generate heat when current passes through them, wherein the plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating regions arranged along the length of the hair contact surface of the multilayer heater; and At least one upper dielectric layer is located above the heater electrode layer to electrically isolate the heater electrode layer; and The number of heating zones per centimeter of the multilayer heater is between 0.6 and 2.5.

[0292] 2. The hair drying and / or styling appliance according to Clause 1, wherein the multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 75 μm and 300 μm.

[0293] 3. The hair drying and / or styling appliance according to clause 1 or 2, wherein the average thermal conductivity of the layers constituting the multilayer heater is less than 300 W / mK and greater than 80 W / mK.

[0294] 4. The hair drying and / or styling appliance according to Clause 3, wherein the average thermal conductivity is averaged over the thickness of the multilayer heater.

[0295] 5. Hair drying and / or styling appliances according to any one of clauses 1 to 4, operable to provide hair drying and / or styling within 4Wcm. -2 and 25 Wcm -2 The power density between the two is used to heat the hair passing through the hair contact surface.

[0296] 6. Hair drying and / or styling appliances according to any one of clauses 1 to 5, wherein the maximum permissible temperature of the heating zone is less than 250°C.

[0297] 7. The appliance according to any one of clauses 1 to 6, wherein the multilayer heater further comprises a heat dissipation layer comprising a plurality of heat sinks that regularize the heating provided in the heating area.

[0298] 8. The appliance according to Clause 7, wherein each radiator is formed as an island to reduce heat diffusion from one heating area to an adjacent heating area.

[0299] 9. The appliance according to Clause 8, wherein the heat sink is formed as interconnected islands, the interconnected islands being electrically interconnected and thermally decoupled from adjacent islands, or wherein adjacent heat sinks do not contact adjacent heat sinks.

[0300] 10. The appliance according to any one of clauses 7 to 9, wherein each radiator is formed of metal.

[0301] 11. The appliance according to any one of clauses 7 to 10, wherein the heat sinks are isolated from each other in a plane perpendicular to the thickness by a solid or semi-solid material having a thermal conductivity of less than 35 W / mK, and most preferably less than 0.3 W / mK.

[0302] 12. The appliance according to any one of clauses 1 to 11, wherein the multilayer heater further comprises one or more of the following: i) A low-friction coating, the upper surface of which provides the hair contact surface of the multilayer heater; ii) A lower dielectric layer disposed below the heater electrode layer; and iii) An auxiliary heater electrode layer, comprising one or more heater electrodes disposed below the heater electrode layer and a dielectric layer disposed between the heater electrode layer and the auxiliary heater electrode layer.

[0303] 13. The appliance according to any one of clauses 1 to 12, wherein one or more layers of the multilayer heater are bonded together using an adhesive, a thermal bond, a physical vapor deposition, a screen printing, or another coating process.

[0304] 14. The appliance according to any one of clauses 1 to 13, wherein one or more of the media layers comprise polyimide.

[0305] 15. The appliance according to any one of clauses 1 to 14, wherein the multilayer heater is flexible and bonded to a rigid structure to provide rigidity to the multilayer heater.

[0306] 16. The appliance according to any one of clauses 1 to 15, wherein the multilayer heater has a flat, curved and / or ribbed heating surface.

[0307] 17. The appliance according to any one of clauses 1 to 16, wherein the multilayer heater provides a flat heating surface and has curved edges that provide a curved heating surface.

[0308] 18. The appliance according to any one of clauses 1 to 17 further includes a controller configured to control the application of electricity to the multilayer heater to control the heat generated by the multilayer heater.

[0309] 19. The appliance according to any one of clauses 1 to 18, wherein the appliance is a single-arm or double-arm device.

[0310] 20. The appliance according to any one of the preceding clauses, wherein the multilayer heater is flexible and mounted to a rigid support, wherein the ends of one or more heater electrodes are disposed on at least one connecting protrusion folded under the rigid support.

[0311] 21. The appliance according to clause 20, wherein a rigid circuit board is disposed below the rigid support, and wherein a plurality of spring clips are disposed for forming an electrical connection between terminals on the rigid circuit board and terminals of the one or more heater electrodes disposed on the connecting protrusion.

[0312] 22. The appliance according to any one of clauses 1 to 21, wherein the upper dielectric layer has a dielectric breakdown strength greater than 500 volts and a dielectric strength of 9.35 × 10⁻⁶ volts. -4 KW -1 cm 2 With 0.8 KW -1 cm 2 The thermal resistance between them.

[0313] 23. A method for manufacturing hair drying and / or styling appliances, the method comprising: A multi-layer heater with multiple functional layers bonded together is provided; The multi-layer heater is installed within the appliance such that, during user use of the appliance, hair comes into contact with the hair contact surface of the multi-layer heater and is heated by conduction. The multi-layer heater includes: A heater electrode layer is provided, comprising a plurality of independently powerable heater electrodes formed of a conductive material, which generate heat when current passes through them. The plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating regions arranged along the length of the hair contact surface of the multilayer heater. At least one upper dielectric layer is provided, which is located above the heater electrode layer to electrically isolate the heater electrode layer; and The number of heating zones per centimeter of the multilayer heater is between 0.6 and 2.5.

[0314] Aspect 5

[0315] 1. A hair drying and / or styling appliance comprising a multi-layer heater having multiple functional layers bonded together, wherein the multi-layer heater is mounted within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater comprises: A heater electrode layer comprising one or more heater electrodes formed of a conductive material, wherein the one or more heater electrodes generate heat when an electric current passes through them; and At least one upper dielectric layer is located above the heater electrode layer to electrically insulate the heater electrode layer; The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 30 μm and 2 mm; and The upper surface of the dielectric layer and / or the coating applied to the upper surface of the dielectric layer provide the hair contact surface of the multilayer heater.

[0316] 2. The appliance according to Clause 1 includes a fan for generating an airflow that passes through or through an opening in the multilayer heater and is heated by the multilayer heater.

[0317] 3. The appliance according to any one of clauses 1 or 2, wherein the heater has a strength greater than 2 W / cm². 2 And less than 100 W / cm 2 Preferably greater than 8 W / cm 2 The power density.

[0318] 4. The appliance according to any one of clauses 1 to 4, wherein the dielectric layer is directly mounted on the upper surface of the heater electrode layer.

[0319] 5. The appliance according to any one of clauses 1 to 3, wherein the multilayer heater further comprises a sensor layer including conductive rails whose resistance changes with temperature, wherein the dielectric layer is directly mounted on the upper surface of the sensor layer.

[0320] 6. The apparatus according to Clause 5, wherein the second dielectric layer is disposed between the sensor layer and the heater electrode layer.

[0321] 7. The appliance according to any one of clauses 1 to 6, wherein the heater electrode layer comprises a plurality of independently controllable heater electrodes defining corresponding plurality of heating areas on the hair contact surface of the multilayer heater.

[0322] 8. The appliance according to Clause 7, wherein the multilayer heater further includes at least one heat dissipation layer disposed below the electrode layer of the heater, the heat dissipation layer including a plurality of heat sinks that regularize the heating provided in the heating area.

[0323] 9. The appliance according to Clause 8, wherein each radiator is formed as an island that does not contact adjacent radiators, so as to minimize heat diffusion from one heating area to adjacent heating areas.

[0324] 10. The appliance according to clause 8 or 9, wherein each radiator is formed of metal.

[0325] 11. The appliance according to any one of clauses 8 to 10, wherein the heat sinks are isolated from each other in a plane perpendicular to the thickness by a solid or semi-solid material having a thermal conductivity of less than 35 W / mK, and preferably less than 0.3 W / mK.

[0326] 12. The appliance according to any one of clauses 1 to 11, wherein the individual layers of the multilayer heater are bonded together to have a peel strength of at least 0.35 Newtons / mm.

[0327] 13. The appliance according to any one of clauses 1 to 12, wherein the multilayer heater further comprises one or more of the following: ii) A lower dielectric layer disposed below the heater electrode layer; and iii) An auxiliary heater electrode layer, comprising one or more heater electrodes disposed below the heater electrode layer and a dielectric layer disposed between the heater electrode layer and the auxiliary heater electrode layer.

[0328] 14. The appliance according to any one of clauses 1 to 13, wherein one or more layers of the multilayer heater are bonded together using an adhesive, a thermal bond, a physical vapor deposition, a screen printing, or another coating process.

[0329] 15. The appliance according to any one of clauses 1 to 14, wherein one or more of the media layers comprise polyimide.

[0330] 16. The appliance according to any one of clauses 1 to 15, wherein the multilayer heater is flexible and bonded to a rigid structure to provide rigidity to the multilayer heater.

[0331] 17. The appliance according to any one of clauses 1 to 16, wherein the multilayer heater has a flat, curved and / or ribbed heating surface.

[0332] 18. The appliance according to any one of clauses 1 to 17, wherein the multilayer heater provides a flat heating surface and has curved edges that provide a curved heating surface.

[0333] 19. The appliance according to any one of clauses 1 to 18 further includes a controller configured to control the application of electricity to the multilayer heater to control the heat generated by the multilayer heater.

[0334] 20. The appliance according to any one of clauses 1 to 19, wherein the appliance is a single-arm or double-arm device including a handle.

[0335] 21. The appliance according to any one of the preceding clauses, wherein the multilayer heater is flexible and mounted to a rigid support, wherein the ends of one or more heater electrodes are disposed on at least one connecting protrusion folded under the rigid support.

[0336] 22. The appliance according to clause 21, wherein a rigid circuit board is disposed below the rigid support, and wherein a plurality of spring clips are disposed for forming an electrical connection between terminals on the rigid circuit board and terminals of the one or more heater electrodes disposed on the connecting protrusion.

[0337] 23. A method for manufacturing hair drying and / or styling appliances, the method comprising: A multi-layer heater with multiple functional layers bonded together is provided; The multi-layer heater is installed within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater is configured as follows: A heater electrode layer is provided, comprising one or more heater electrodes formed of a conductive material, which generate heat when current passes through them; and At least one upper dielectric layer is provided above the heater electrode layer to electrically isolate the heater electrode layer from the hair contact surface; The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 30 μm and 2 mm; and The upper surface of the dielectric layer and / or the coating applied to the upper surface of the dielectric layer provide the hair contact surface of the multilayer heater.

Claims

1. A hair drying and / or styling appliance comprising a multi-layer heater having multiple functional layers bonded together, wherein, The multi-layer heater is installed within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater comprises: A heater electrode layer comprising one or more heater electrodes formed of a conductive material, wherein the one or more heater electrodes generate heat when an electric current passes through them; and At least one upper dielectric layer is located above the heater electrode layer to electrically insulate the heater electrode layer; The upper surface of the dielectric layer provides the hair contact surface of the multilayer heater.

2. The appliance according to claim 1, wherein, The at least one dielectric layer is formed as a coating on the upper surface of the heater electrode layer.

3. The appliance according to claim 2, wherein, The coating is applied as a spray, paint, physical vapor deposition, sputtering, or evaporation.

4. The appliance according to any one of claims 1 to 3, wherein, The heater has a strength greater than 2 W / cm². 2 And less than 100 W / cm 2 Preferably greater than 8 W / cm 2 The power density.

5. The appliance according to any one of claims 1 to 4, wherein, The dielectric layer is directly mounted on the upper surface of the heater electrode layer.

6. The appliance according to any one of claims 1 to 5, wherein, One or more of the heater electrodes are formed of a conductive material whose resistance changes with the temperature of the heater, thereby allowing the temperature of the hair shrinkage surface to be determined by measuring the resistance of the one or more heater electrodes.

7. The appliance according to any one of claims 1 to 6, wherein, The heater electrode layer includes a plurality of independently controllable heater electrodes that define corresponding heating areas on the hair contact 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 one of claims 7 to 9, wherein, The multilayer heater also includes at least one heat dissipation layer disposed below the electrode layer of the heater.

11. The appliance according to claim 10, wherein, The second dielectric layer is disposed between the heater electrode layer and the heat dissipation layer.

12. The appliance according to claim 10 or 11, wherein, The heat dissipation layer includes multiple heat sinks, which regularize the heating provided in the heating area.

13. The appliance according to claim 12, wherein, when subordinate to claim 9, A heat sink is provided for each row of independently controllable heater electrodes.

14. The appliance according to claim 12, wherein, At least one heat sink is provided for each heater electrode.

15. The appliance according to any one of claims 12 to 14, wherein, Each radiator is formed as an island that does not contact adjacent radiators, in order to minimize heat diffusion from one heating area to adjacent heating areas.

16. The appliance according to any one of claims 12 to 15, wherein, Each radiator is made of metal.

17. The appliance according to any one of claims 12 to 16, wherein, The heat sinks are isolated from each other in a plane perpendicular to their thickness by solid or semi-solid materials, the thermal conductivity of which is less than 35 W / mK, and preferably less than 0.3 W / mK.

18. The appliance according to any of the preceding claims, wherein, The multilayer heater further includes an auxiliary heater electrode layer, which includes one or more heater electrodes disposed below the heater electrode layer and a dielectric layer disposed between the heater electrode layer and the auxiliary heater electrode layer.

19. The appliance according to any one of claims 1 to 18, wherein, The multilayer heater is flexible and bonded to a rigid structure to provide rigidity to the multilayer heater.

20. The appliance according to any one of claims 1 to 19, wherein, The multilayer heater has a flat, curved, and / or ribbed heating surface.

21. The appliance according to any one 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 one of claims 1 to 21, further comprising a controller configured to control the electrical application to the multilayer heater to control the heat generated by the multilayer heater.

23. The appliance according to any one of claims 1 to 22, wherein, The device is a single-arm or double-arm device including a handle.

24. The appliance according to any of the preceding claims, wherein, The multilayer heater is flexible and is mounted to a rigid support, wherein the ends of the one or more heater electrodes are disposed on at least one connecting protrusion folded under the rigid support.

25. The appliance according to claim 24, wherein, A rigid circuit board is disposed below the rigid support member, and a plurality of spring clips are provided therein for forming an electrical connection between terminals on the rigid circuit board and terminals of one or more heater electrodes disposed on the connecting protrusion.

26. The appliance according to any one of claims 1 to 25, wherein, The upper dielectric layer has a dielectric breakdown strength greater than 500 volts and a dielectric strength of 9.35 × 10⁻⁶ volts. -4 KW -1 cm 2 With 0.8 KW -1 cm 2 The thermal resistance between them.

27. A method for manufacturing a hair drying and / or styling appliance, comprising: A multi-layer heater with multiple functional layers bonded together is provided; The multi-layer heater is installed in the appliance such that during user use of the appliance, hair comes into contact with the hair contact surface of the multi-layer heater and is heated by conduction; wherein, the multi-layer heater is provided by: A heater electrode layer is provided, comprising one or more heater electrodes formed of a conductive material, the one or more heater electrodes generating heat when an electric current passes through the one or more heater electrodes; and At least one upper dielectric layer is provided on the heater electrode layer to electrically isolate the heater electrode layer from the hair contact surface; The upper surface of the dielectric layer provides the hair contact surface of the multilayer heater.

28. A hair drying and / or styling appliance comprising a multi-layer heater having multiple functional layers bonded together, wherein, The multi-layer heater is installed within the appliance such that, during user use of the appliance, hair comes into contact with the hair contact surface of the multi-layer heater and is heated by conduction. The multilayer heater includes: A heater electrode layer comprising a plurality of independently powered heater electrodes formed of a conductive material, wherein the plurality of heater electrodes generate heat when current passes through them, wherein the plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating regions arranged along the length of the hair contact surface of the multilayer heater; and At least one upper dielectric layer is located above the heater electrode layer to electrically isolate the heater electrode layer; and The number of heating zones per centimeter of the multilayer heater is between 0.6 and 2.

5.

29. The appliance according to claim 28, wherein, The upper dielectric layer has a dielectric breakdown strength greater than 500 volts and a dielectric strength of 9.35 × 10⁻⁶ volts. -4 KW -1 cm 2 With 0.8 KW -1 cm 2 The thermal resistance between them.

30. The appliance according to claim 28 or 29, wherein, The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 75 μm and 300 μm.

31. The appliance according to any one of claims 28 to 30, wherein, The average thermal conductivity of the layers constituting the multilayer heater is less than 300 W / mK and greater than 80 W / mK.

32. The appliance according to claim 31, wherein, The average thermal conductivity is the average of the thicknesses of the multilayer heater.

33. The appliance according to any one of claims 28 to 32, wherein, The heater electrode is configured to provide at 4 W / cm² -2 and 25 Wcm -2 The power density between the two is used to heat the hair passing through the hair contact surface.

34. The appliance according to any one of claims 28 to 33, wherein, The maximum permissible temperature of the heating zone is less than 250℃.

35. The appliance according to any one of claims 28 to 34, wherein, The multilayer heater further includes an auxiliary heater electrode layer, which includes one or more heater electrodes disposed below the heater electrode layer and a dielectric layer disposed between the heater electrode layer and the auxiliary heater electrode layer.

36. A method for manufacturing a hair drying and / or styling appliance, comprising: A multi-layer heater with multiple functional layers bonded together is provided; The multi-layer heater is installed in the appliance such that during the user's use of the appliance, the hair comes into contact with the hair contact surface of the multi-layer heater and is heated by conduction. The multi-layer heater includes: A heater electrode layer is provided, comprising a plurality of independently powerable heater electrodes formed of a conductive material, which generate heat when current passes through them. The plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define corresponding plurality of heating regions arranged along the length of the hair contact surface of the multilayer heater. At least one upper dielectric layer is provided, which is located above the heater electrode layer to electrically isolate the heater electrode layer; and The number of heating zones per centimeter of the multilayer heater is between 0.6 and 2.

5.

37. A multi-layer heater for hair drying and / or styling appliances, said multi-layer heater having multiple functional layers bonded together, wherein, The multi-layer heater provides a hair contact surface to heat the hair in contact with the multi-layer heater, wherein the multi-layer heater includes: A heater electrode layer comprising one or more heater electrodes formed of a first conductive material, wherein the one or more heater electrodes generate heat when an electric current passes through them; A heat dissipation layer comprising one or more heat sinks, each heat sink being formed of a second conductive material different from the first conductive material; and At least one dielectric layer is sandwiched between the heater electrode layer and the heat dissipation layer.

38. The multilayer heater according to claim 37, wherein, The heater electrode layer includes a plurality of independently powered heater electrodes formed of a conductive material. When current passes through the plurality of heater electrodes, the plurality of heater electrodes generate heat. The plurality of heater electrodes are arranged sequentially along the length of the multilayer heater and define a plurality of corresponding heating areas arranged along the length of the hair contact surface of the multilayer heater.

39. The multilayer heater according to claim 38, wherein, The heat sink layer includes multiple heat sinks.

40. The multilayer heater according to any one of claims 37 to 39, wherein, The multilayer heater has a thickness measured on all of the plurality of layers of the multilayer heater, the thickness being between 30 μm and 2 mm, and preferably between 75 μm and 300 μm.

41. The multilayer heater according to any one of claims 37 to 40, wherein, The first conductive material includes steel, and the second conductive material includes copper.

42. The multilayer heater according to any one of claims 37 to 41, comprising an upper dielectric layer disposed on the surface of the electrode layer of the heater, and said upper dielectric layer having a dielectric breakdown strength greater than 500 volts and a dielectric strength of 9.35 × 10⁻⁶ volts. -4 KW -1 cm 2 With 0.8 KW -1 cm 2 The thermal resistance between them.

43. A hair drying and / or styling appliance comprising a multi-layer heater having multiple functional layers bonded together, wherein, The multi-layer heater is installed within the appliance such that during user use of the appliance, hair contacts the hair contact surface of the multi-layer heater and is heated by conduction, wherein the multi-layer heater comprises: A heater electrode layer comprising one or more heater electrodes formed of a conductive material, wherein the one or more heater electrodes generate heat when an electric current passes through them; At least one dielectric layer is located above the heater electrode layer to electrically isolate the heater electrode layer; The heater is supported within the housing of the appliance by a rigid support member; the terminals of the one or more heater electrodes are disposed on a connecting protrusion folded below the rigid support member; a rigid circuit board is disposed below the rigid support member, the rigid circuit board carrying a drive and control circuit system for controlling the heating of the multilayer heater; and a plurality of spring clips are configured to form an electrical connection between the terminals on the rigid circuit board and the terminals of the one or more heater electrodes disposed on the connecting protrusion.

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