Field of the Invention

The present invention relates to a hair roller and to a hair roller kit.

Background of the Invention

Hair rollers are commonly used for treating or styling hair, for instance to shape or curl the hair. When rolled into a person’s hair, the hair can be heated to change the internal structure of the hair and cause the hair to curl. Hot hair rollers are pre-heated before being rolled into the hair where the heat stored in the thermal mass of the hot hair roller is transferred to the hair.

Summary of the Invention

According to a first aspect of the present invention there is provided a hair roller. The hair roller comprises: a housing, a thin-film heater, and an electrical connector. A section of hair can be wrapped around the housing and, in use, the thin-film heater heats the hair roller to transfer heat to the hair wrapped around the housing. The electrical connector is connectable to an external electrical energy supply. In use, connecting the electrical connector the external electrical energy supply enables electrical energy to be delivered to the thin-film heater to cause heating of the hair roller. The thin-film heater is an electrically-powered heater.

According to a second aspect of the present invention there is provided a hair roller. The hair roller comprises: a housing, an electrically-powered heater, and an electrical connector. A section of hair can be wrapped around the housing and, in use, the electrically-powered heater heats the hair roller to transfer heat to the hair wrapped around the housing. The electrical connector is removably connectable to an electrical supply connector of a power applicator. In use, the electrical connector is to receive electrical energy from the electrical supply connector for delivery to the electrically-powered heater. The power applicator is configured so that the electrical energy can supplied to the electrical connector from the electrical supply connector when the hair is wrapped around the housing of the hair roller.

The electrically-powered heater may comprise a resistive heater. In other embodiments, the electrically-powered heater may comprise an inductive heating system comprising an inductor and a susceptor where the susceptor heats the hair roller, for instance by heating the housing. The resistive heater may comprise a thin-film heater wrapped around the portion of housing around which the hair is rolled.

Where the hair roller comprises a thin-film heater, the thin-film heater may comprise one or more resistive heating elements. The thin-film heater can provide a large contact area with the housing relative to the size of the heater.

The resistive heating element(s) may be supported on, or embedded within, a superstructure of the thin-film heater. The resistive heating element(s) may be supported on an insulating substrate. The insulating substrate may comprise a polyimide substrate. The resistive heating element(s) may be sandwiched between layers of an insulating material.

The heating element(s) of the thin-film heater may comprise: a cut metal shim, an etched foil resistor, or a printed resistor. The heating element(s) may be connected to terminals at each end. The heating element(s) may have an electrical resistance of between 0.2 ohm and 5 ohms. The heating element(s) may be laid out in parallel lines that are connected at the ends. The heating element(s) lines may be spaced apart from each other by between 0.3mm and 5mm. The small spacing between the heating element(s) lines means the heating element can cover a larger surface area of the housing. The thin-film heater may have a thickness of less than 50p.m. The thin-film heater may weigh less than 3 grams. The thin-film heater may be is wrapped around the housing. The thin-film heater may have electrical connections that pass through the housing.

The thin-film heater may use more than 250W. The thin-film heater may use approximately 270W. The thin-film heater 14 may use up to 400W. The thin-film heater may heat the hair roller to a temperature of 120 °C over a period of approximately 10s.

The hair roller may comprise an insulator wrapped around the housing to encapsulate the thin-film heater. The insulator may define an external surface of the hair roller. The insulator can protect the electrically-powered heater from damage and prevent a user contacting a heating element of the electrically-powered heater.

The hair roller may comprise a temperature monitoring unit to measure or react to the temperature of the housing or of the electrically-powered heater. The temperature monitoring unit allows the hair roller to be heated to, and controlled at, a specified temperature or temperature profile over a period of heating the electrically-powered heater. The temperature monitoring unit may comprise a thermal switch. The thermal switch may comprise a bimetallic strip.

The hair roller may comprise a water retaining layer configured to release moisture to the hair as the hair roller is heated. The water retaining material may be understood as a material capable of absorbing and holding liquid water as the hair roller is handled and fixed in the hair and gradually releasing the water as moisture as the hair roller is heated by the power applicator. In some examples, the water retaining material may be referred to as a water absorbing or water adsorbing material.

During a styling session, the user may add liquid water to the water retaining layer, wrap the hair around the hair roller, and thereafter heat the hair roller. The heating causes the water in the retaining layer to start diffusing into the hair as hot vapour. The hot vapour penetrating the wrapped hair allows for a more efficient and even heating of the hair layers arranged around the roller, which hence are both heated and provided with moisture. The phase transition of the water from liquid to vapour phase may be understood as a constanttemperature process, which at atmospheric pressure generally takes place at approximately 100°C. Hence, the water retaining capability of the hair roller allows for an improved temperature control and a reduced risk of overheating and thermal damage of the hair.

It will be appreciated that the water may be added to prior to arranging the hair roller in the hair, or after. Similarly, the roller may be pre-heated, that is, heated before it is arranged in the hair, or after, as discussed above.

Further, it is understood that the water retaining layer may be combined with the abovedescribed temperature monitoring unit to further reduce the risk of overheating. The temperature monitoring unit, such as the thermal switch, may for example be employed to control the temperature after consumption of the liquid water, i.e., after a complete phase transition into vapour.

The water retaining layer may be fixed to the housing, i.e., attached in a non-removable way. Alternatively, the layer may be detachable, allowing the user to replace the water retaining layer with a fresh one after use.

In an example, the water retaining layer is provided as a sleeve configured to at least partly encapsulate a portion of the housing of the hair roller. The water retaining layer, such as a sleeve, may be fixedly attached to the housing or detachably attached and replaced after use. The water retaining layer may be formed of a stretchable or elastic material to facilitate a good fit with the shape of the housing.

The water retaining layer may comprise a fibrous material, such as woven or non-woven fabrics, or a pulp-based material such as, for example, paper. In an example, the water retaining layer comprises a hygroscopic material. Such a material is capable of attracting and holding water molecules from the surrounding environment and includes salts, such as calcium chloride and lithium chloride. The hygroscopic material may be added to the water retaining material as discussed above, such as a fibrous or paper sleeve. The hygroscopic material may attract atmospheric moisture, thereby reducing the need for the user to actively add water to the water retaining layer.

The hair roller may further comprise a cover layer arranged to at least partly encapsulate the hygroscopic material. The cover layer may be configured to repel water and allow water vapour to pass through the cover layer, into the hair wrapped around the housing. Such a cover may be referred to as a waterproof, breathable membrane. The cover layer may be employed to encapsulate the liquid held by the water retaining material and give the user the experience of a dry surface when handling the hair roller. At the same time, the cover layer may allow for water molecules, or moisture, to pass from the surrounding environment into the water retaining layer and be released into the hair upon heating. After use, the water retaining layer may re-absorb moisture from the surrounding air until the hygroscopic material is saturated and ready for use.

The cover layer may, for example, be formed of a non-woven polypropylene or polyester fabric.

In some examples, the housing comprises a hydrophobic surface portion. The hydrophobic surface portion may be arranged to repel water from parts of the hair roller that are not intended to retain water, thereby reducing the risk for deposits, such as limescale, to accumulate on the hair roller. Further, the hydrophobic surface may assist in concentrating the water to the water retaining layer, thereby providing a feeling of a dry surface improving the user experience.

The housing may conform to a hollow tube, with the hydrophobic surface arranged on the inner surface of the housing. The hydrophobic surface allows excess water in the inner surface to form beads and fall off the hair roller, thereby concentrating the water to the water retaining material. A relatively dry inner surface may be of particular interest for configurations in which the hair roller is heated by a heating wand that is inserted into the tubular housing, as this may reduce the vapour generated at the interface between the heating wand and the housing and improve the heat transfer efficiency.

Heating the hair roller allows a user to have free hands once the hair roller is fixed in the user’s hair. Using a thin-film heater allows the hair roller to be made lightweight in comparison with a pre-heated hair roller that relies on a substantial thermal mass, which can be very heavy, to store the energy from the pre-heating station. Due to the low thermal mass of a thin-film heater, the hair roller can be heated up rapidly. The rapid temperature increase of a low thermal mass heater makes heating the hair rollers on a user’s head easier. Moreover, the hair roller can be cold on insertion into the hair that is to be treated meaning that there is no cause for discomfort to a hair roller user or burning of their fingers. The rapid heat up and the ease of insertion can mean that the total styling time for a user will be lower. As no pre-heat is required before insertion, the initial temperature to which the hair roller is heated can be lower meaning the treated hair will not be as damaged by the treatment.

According to a third aspect of the present invention there is provided a hair roller power applicator for applying electrical energy to a hair roller comprising an electrically- powered heater. The power applicator comprises: an electrical supply connector, an electrical energy source to supply electrical energy to the electrical supply connector, and a control system to control the supply of electrical energy to the electrical supply connector. The electrical supply connector is removably connectable to an electrical connector of the hair roller. The electrical supply connector is to, in use, deliver electrical energy to the electrical connector for delivery to the electrically-powered heater. The power applicator is configured so that the electrical energy can be supplied to the electrical connector when a section of hair on a user’s head is wrapped around the hair roller. The electrical supply connector may be configured to guide the electrical supply connector to connect with the electrical connector of the hair roller. The electrical supply connector may be shaped to guide the electrical supply connector to connect with the electrical connector of the hair roller. The electrical supply connector and/or the electrical connector may comprise a magnet to aid the connecting of the electrical supply connector to the electrical connector.

The hair-heating temperature of the hair roller can be controlled with the power applicator in the present invention making the hair roller more versatile. Accordingly, a variety of heating profiles (heating to a range of temperatures over a heating period) can be implemented in the hair roller. In this way, the hair roller can accommodate different volumes of hair rolled onto the hair roller of the present invention. The hair roller can also accommodate different amounts of water content in hair rolled onto the hair roller of the present invention. The hair roller of the present invention can be heated to and maintained at a range of temperatures over a longer period than for a pre-heated hair roller that relies on having enough thermal mass to store the required thermal energy before insertion into hair. For pre-heated hair rollers, the temperature passively decreases once the pre-heated hair roller is removed from its heating source; in contrast, the hair roller of the present invention can be heated to a desired temperature by the power applicator after the hair rollers have been inserted into the hair. The maximum temperatures to which the hair roller of the present invention can be heated to can be lower than the initial heated temperature of a pre-heated hair roller because the hair roller of the present invention is already in the hair before being heated. Accordingly, the treated hair will not be as damaged by the treatment when the hair roller of the present invention is used. Additionally, being able to control the hair-heating temperature means that the user’s fingers are not burnt during use of the hair roller in the hair, for instance if manipulation in situ is required. Alternatively, or additionally, the control of the hair-heating temperature may be improved by adding water to a water retaining layer as outlined above. By adding water, the power used for heating the hair roller can be increased without risking overheating the hair. Because the electrical supply connector is removably connectable to an electrical connector of the hair roller and the power applicator is configured so that the electrical energy can be supplied to the electrical connector when the hair roller is inserted into a user’s hair on their head, the electrically-powered heater of the hair roller can be powered once the hair roller has been inserted but still permit a user to move around freely. There is no need to rely on power cables fixed to the hair rollers to supply the electrical energy to power the hair rollers, which can make the hair rollers uncomfortable to use and prevent a user with performing other tasks at the same time as treating their hair. Thus, the hair rollers of the present invention are less cumbersome and awkward to use. The hair rollers of the present invention are more comfortable for a user to wear. Furthermore, the hair roller of the present invention is also tidier than a hair roller with fixed power cables, which can be messier as part of a set of cabled hair rollers inserted in a user’s hair.

The electrical energy source may comprise a less than 40V power supply. The electrical energy source may comprise a DC power supply. The electrical energy source may comprise an AC power supply.

The electrical energy source may comprise a lithium-ion battery. The electrical energy source may comprise a lithium-ion battery pack containing two, three, or four cells, or any suitable number of cells. In one example envisioned by the Applicant, the lithium- ion battery pack contains four cells. The battery may provide a voltage of 6V or higher. In one example, the battery provides a voltage of 12V or higher. The battery may have a capacity of at least 5000mAh. In one example, the battery has a capacity of at least lOAh. The battery may deliver at least 180W continuous power. In one example, the battery delivers at least 350W continuous power.

The power applicator may comprise a second electrical connector and a charging unit, the charging unit to deliver electrical energy from a second electrical connector to the battery to recharge the battery. The power applicator may comprise a base unit and a probe. The electrical energy source may be located within the base unit. The probe may comprise the electrical supply connector be connected to the base unit by a power supply cable.

The control system may comprise a user interface through which a user can set a heating duration and a heating temperature for the electrically-powered heater. The control system may comprise an on/off switch. The on/off switch may be incorporated in the user interface. The user interface may comprise a power application switch.

The control system may be connectable to the temperature monitoring unit in use. The connection may be through the electrical supply connector. Connecting to the temperature monitoring unit allows the hair roller to be heated to, and controlled at, a specified temperature or temperature profile over a period of heating the electrically-powered heater.

The control system may comprise a timer unit to control the duration for which electrical energy is supplied to the electrically-powered heater.

The control system may comprise a processor to control the supply of electrical energy to the electrically-powered heater from the electrical energy source.

According to a fourth aspect of the present invention there is provided a hair roller kit comprising: one or more hair rollers according to the first aspect of the invention or the second aspect of the invention, and a power applicator according to the third aspect of the invention to apply electrical energy to the hair rollers.

According to a fifth aspect of the present invention there is provided a hair roller kit comprising: one or more hair rollers according to the first aspect of the invention or the second aspect of the invention, a power applicator, according to the third aspect of the invention, having a battery and a second electrical connector as described herein, and a charging device. The charging device comprises: a second electrical energy supply to deliver electrical energy to the to the power applicator to recharge the electrical energy source; and a charging connector through which the electrical energy from the second electrical energy source is deliverable to the second electrical connector of the power applicator. The charging connector is electrically connectable with the second electrical connector.

The hair roller kits of the fourth or fifth aspects of the present invention may comprise a plurality of hair rollers, each according to the first aspect of the invention or the second aspect of the invention.

According to an embodiment, the power applicator may comprise a heating rod, or heating wand, configured to be inserted into a tubular housing of a hair roller. The heating rod may be used in combination with, or as an alternative to, the above-described electrically powered heater of the hair roller. The hair roller may comprise a hollow interior into which the heating rod can be inserted for transfer of thermal energy to the hair roller. The hair roller may, for instance, have a hollow, tubular shape. It will be appreciated that the heating rod may have a shape corresponding to the shape of the hollow interior of the housing to facilitate insertion as well as heat transfer. Put differently, the heating rod and the hollow interior of the housing may have a matching size and shape. In some examples, the heating rod and the hollow interior of the housing may have matching frustum or conical shapes improving the fit and hence the thermal contact between the rod and the housing.

The heating rod may form a rod-shaped distal part of the power applicator adapted to be inserted into the hair roller. The rod may be attached to a proximal handle part adapted to be gripped by the user. The distal part may further be detachable and replaced with differently sized parts matching hair rollers of various diameters.

A temperature control arrangement may be provided for reducing the risk of overheating the hair during the styling. The temperature control system may, for example, be configured to monitor the time during which heat is applied to a roller. After a predetermined heating duration, the temperature control arrangement may indicate to the user that it is time to remove the heating rod from the roller or switch off the heating of the rod. The timer may start counting when the rod has been inserted in the hair roller (e.g., in response to a detector indicating physical contact between the two), or when manually activated by the user (e.g., by triggering a switch activating the heating).

Alternatively, or additionally, the temperature control arrangement comprises a temperature sensor monitoring a temperature of the hair roller, or the hair wrapped around the hair roller, and a control circuit arranged to either indicate to the user that a predetermined temperature has been reached or cause the heating of the rod to be switched off.

The indication to the user may for example be provided by means of tactile feedback, such as a vibrator, audible feedback, such as a buzzer, or a visual indicator.

Optional features of aspects of the present invention may be equally applied to other aspects of the invention, where appropriate. of the Drawings

Figure l is a schematic view of a hair roller according to the present invention;

Figurea 2a and b are schematic cross-sectional views through hair rollers according to the present invention 1 ;

Figures 3 a and b are schematic views of hair roller kits according to the present invention, each kit comprising a hair roller and an embodiment of a hair roller power applicator according to the present invention;

Figure 4 is a schematic diagram of a hair roller power applicator according to the present invention; Figure 5 is a schematic view of a hair roller kit according to the present invention comprising a plurality of hair rollers, a hair roller power applicator, and a charging device;

Figure 6 is a schematic view of a hair roller kit according to the present invention comprising a hair roller and an embodiment of a hair roller power applicator according to the present invention;

Figure 7 is a schematic diagram of a hair roller power applicator according to the present invention; and

Figure 8 is a schematic view of a hair roller kit according to the present invention comprising a hair roller and an embodiment of a hair roller power applicator.

Detailed Description of the Invention

A hair roller 10 according to the present invention is shown schematically in Figure 1. Hair can be rolled around the hair roller 10 so that the hair can be curled. The hair roller 10 is heatable so that heat is transferable to the hair rolled around the hair roller 10 thereby curling the hair and to fixing the hair in a curled shape. The hair roller 10 may be heated either by supplying electrical energy to an electrically-powered heater arranged in the hair roller 10, or by transferring thermal energy inserting a heating rod or heating wand into an interior of the hair roller 10.

In the embodiment shown in the figures, the hair roller 10 is generally cylindrical or tubular in shape and extends from a first end 24 to a second end 26. In some embodiments the hair roller 10 has a frustum shape or a conical shape, with a first end 24 being slightly wider than the second end 26. The outer surface 22 of the hair roller 10, which hence may be a cylindrical surface 22, is configured to contact hair rolled around the hair roller 10. When the hair roller is heated, heat is transferred to the hair from the surface 22, which may be referred to as the working surface. Optionally, as in the embodiment shown in Figure 1, the hair roller 10 comprises a plurality of bristles 28 that aid in gripping the hair rolled onto the hair roller 10. Each bristle of the plurality of bristles 28 projects in an outwardly direction of the surface 22. In another embodiment, the hair roller 10 is covered with a fibrous material forming the cylindrical surface 22 to reduce hair slipping around when wrapping hair around the hair roller 10. The hair roller 10 may, or may not, comprise the plurality of bristles 28 in the embodiment where the hair roller 10 is covered with a fibrous material. In further embodiments, the hair roller 10 is at least partly covered with a water retaining layer configured to release moisture to the hair when the hair roller 10 is heated. The water retaining layer is described in more detail in connection with Figure 2b.

The hair roller comprises a housing 20 that defines the general shape of the hair roller 10 around which a section of hair is wrappable, in this instance the cylindrical shape of the hair roller 10.

Figure 2a schematically illustrates a cross-sectional view through a hair roller 10, which may be similarly configured as the hair roller of Figure 1. The housing 20 defines an enclosure 21 for containing and protecting certain components of the hair roller 10. In the illustrated embodiment, the housing 20 comprises a substantially hollow tube and an end cap located each of the first 24 and second 26 ends. The housing 20 may have a diameter of between 25mm and 50mm. The housing 20 may have a wall thickness of between 0.3mm and 2mm. The housing 20 comprises a material that can sustain being held at a temperature suitable for heat treating hair, for example a temperature of more than 150°C. The housing 20 may comprise a plastics material.

The hair roller 10 according to the present embodiment comprises an electrically-powered heater. The electrically-powered heater is to heat the hair roller 10 so that the hair roller transfers heat to hair rolled around the hair roller 10. Alternatively, or additionally, the hair roller 10 is configured to be heated by a heating rod 125 or wand in thermal contact with the hair roller 10. An example of such an embodiment is shown in Figure 3b. The electrically-powered heater of the embodiment in Figure 2a may comprise a resistive heater. As explained above, other electrically-powered heater configurations than a resistive heater may be implemented to heat the hair roller 10. In the embodiment shown in Figure 2a, the electrically-powered heater comprises a resistive thin-film heater 14. The thin-film heater 14 may comprise one or more resistive heating elements. The heating element(s) may be connected to terminals at each end that, in turn, permit connection of the thin-film heater 14 to other electrical components of the hair roller 10. Thin-film heaters include lightweight and flexible heaters that have a high tensile strength and a high resistance to tearing despite having a thickness that may be a fraction of a millimetre. For example, the thin-film heater 14 may have a thickness of less than 50pm. Being thin permits the thin-film heater 14 to be lightweight, for example less than 3 grams. Thin- film heaters can have a low thermal mass thereby reducing the overall weight of the hair roller 10, which can make the use of the hair roller 10 more comfortable for a user. Thin- film heaters have a resistive heating element(s) that is supported on, or embedded within, a superstructure of the thin-film heater. For example, the resistive heating element may be supported on an insulating substrate, such as a polyimide substrate. The resistive heating element may be sandwiched between layers of an insulating material, such as layers of polyimide.

The heating element of the thin-film heater 14 may comprise a cut metal shim, an etched foil resistor, or a printed resistor. The heating element may have an electrical resistance of between 0.2 ohm and 5 ohms. The heating element circuit may have a tortuous, or snaking, path that allows control of the heat emitted by the thin-film heater 14. For instance, the heating element may emit more, or less, heat in one heating zone than in another zone thereby permitting the hair roller to be heated with a desired heating pattern. The heating element circuit may be laid out so that the hair roller 10 is heated evenly across the whole of the cylindrical surface 22. In one example, the heating element may be laid out in parallel lines that are connected at the ends. The heating element lines may be spaced apart from each other by between 0.3mm and 5mm, for example spaced apart by 0.4mm. The heating element of the thin-film heater 14 may comprise a single strip wrapped around the housing 20 with small gap, such as 0.3mm, between each turn. The heating element of the thin-film heater 14 may comprise a shim that can substantially cover the area of the housing 20 working surface and have small slots, such as 0.3mm, cut into the shim. The thin-film heater 14 is a low-temperature heater, that is the heater is not configured to cause combustion by generating heat. The thin-film heater 14 may use more than 250W. For example, the thin-film heater may use 270W. In some examples, the thin-film heater 14 may use up to 400W. The thin-film heater 14 may heat the hair roller 10 to a temperature of 120°C over a short period - for example, the thin-film heater 14 may heat the hair roller 10 to this temperature in 10s or less at a power supply of270W. The thin-film heater 14 is generally cylindrically shaped to match the housing 20. For instance, the flexible thin-film heater 14 is wrapped around the tubular housing 20. In some examples, the thin-film 14 is securely fixed to the housing 20, for example on the cylindrical surface of the housing 20. The thin-film heater 14 has electrical connections that pass through the housing 20 wall into the enclosure 21.

An insulator 16 is wrapped around the housing 20 thereby encapsulating the thin-film heater 14 between the insulator 16 and the housing 20. The insulator 16 protects the thin- film heater 16 from damage and helps prevent a user contacting the heating element of the thin-film heater 14. The insulation 16 may be in addition to an insulating layer on top of the heating element of the thin-film heater 14. Alternatively, the insulator 16 may be the only insulating layer between the heating element of the thin-film heater 14 and external surface of the hair roller 10. The insulator 16 forms the external cylindrical surface 22 of the hair roller 10. Heat generated in the heater is therefore transferred through the insulator 16 to hair rolled onto the hair roller. The insulator may comprise any suitable material that can sustain being held at a temperature suitable for heat treating hair. The insulator 16 may comprise a plastics material, a metal, or a metal alloy, or a fibrous material, for example. It will be understood that in some embodiments, the insulator 16 is not present and the thin-film heater 14 can form the outer surface of the hair roller 10. Thus, heat will be transferred from the hair roller 10 directly from a surface of the thin-film heater 14. A thermally conductive layer, which is to act as a thermal spreader layer, may be placed between the thin-film heater 14 and the insulator 16. For example, the thermally conductive layer may comprise an aluminium shim. The thermally conductive layer may be located between the insulation 16 and any insulating layer on top of the heating element of the thin-film heater 14. A second thermally conductive layer, which is also to act as a thermal spreader layer, may be placed between the thin-film heater 14 and the housing 20. For example, the second thermally conductive layer may comprise an aluminium shim. The first and second thermally conductive layers may be electrically insulated from the thin-film heater 14. As thermal spreader layers, the first and second thermally conductive layers assist the heat distribution evenly across the hair roller surface.

As illustrated in Figure 2a, the hair roller may comprise a temperature monitoring unit 34 that is mounted to the inside of the tubular housing 20 and that measures, or reacts to, the temperature of the housing 20, which is heated by electrically-powered heater in use. In some embodiments, the temperature monitoring unit is instead mounted to, or incorporated in, the electrically-powered heater itself. For example, the temperature monitoring unit may be a surface-mounted component of the thin-film heater 14. In some embodiments, the temperature monitoring unit 34 is a temperature sensor that provides a temperature measurement signal. In other embodiments, the temperature monitoring unit 34 is a thermal switch, for example a bimetallic strip, that opens and cuts off the supply of electrical energy to the heater when the desired heating temperature for hair on the hair roller has been exceeded.

Figure 2b schematically illustrates a cross-sectional view through a hair roller 10, which is similarly configured as the hair roller shown in Figure 2a. As indicated in the present figure, the hair roller 10 comprises a water retaining layer 17 for releasing moisture, in the form of water vapour, to the hair as the hair roller 10 is being heated. Since the vaporisation of water is known to be an isothermal process, the presence of water in the water retaining layer 17 reduces the risk of overheating the hair. The water retaining layer 17 may hence replace the above-mentioned temperature monitoring unit 34. However, it is also possible to combine the water retaining layer 17 and the temperature monitoring unit 34 to further improve the temperature control.

The water retaining layer 17 may be formed of a fibrous material, such as woven or nonwoven fabrics, or a pulp-based material such as, for example, paper. Specific examples of materials for the water retaining layer 17 include elastic nylon, nylon combined with other stretchable materials such as spandex, and non-stretchable fabrics such as plain- woven fabric which can be bonded with a strip of elastic fabric to attach the layer 17 around the hair roller 10. The water retaining material may have relatively good wicking properties to facilitate fast and even water uptake when exposed to water.

The water-retaining layer 17 is provided in the shape of a sleeve that can be fitted over the housing, and may further be fixed to the housing, for instance by means of an adhesive, or floating, facilitating removal and replacement of the sleeve 17 after use.

As shown in Figure 2b, the housing comprises fitting means, such as flanges or shoulders 23 arranged at one or both of the end portions 24, 26 of the housing 20 to prevent the sleeve 17 sliding off the housing 20 during handling and use. The flanges 23 may protrude approximately 5mm from the outer surface of the housing and may be attached to the outer surface by means of an adhesive such as silicone.

The water retaining layer 17 is arranged to at least partly cover the outer surface of the housing 20, for example as a piece of fabric that is wrapped around the housing 20 and whose edges are secured to each other, or as a textile-based sleeve 17 that is pulled over the fitting means 23 and around the housing 20. The sleeve 17 may in some embodiments be elastic or stretchable to facilitate attachment and removal of the sleeve 17.

The water retaining layer 17 is arranged on an insulator 16 and/or a thermally conductive layer, as mentioned above. As shown in the example illustrated in Figure 2b, the water retaining layer 17 forms the outermost layer of a structure comprising a thin-film heater 14 arranged around the housing 20, and an insulator 16 wrapped around the thin-film heater 14.

During use, i.e., a styling session, the water retaining layer 17 may be wetted by spraying water onto the layer 17 or immersing the entire hair roller 10 in water. The water may be de-ionised. The absorbed amount of water may lie in the range of 0.5-1.2g, depending on the size of the hair roller 10 and the size of the hair tress that is to be styled. It will be appreciated that the hair roller 10 may be wetted before it is installed in the hair. However, it is also possible to wet the hair roller 10 after it has been installed, for instance by spraying.

In some examples, the water retaining layer 17 comprises a material or substance arranged to attract and hold water molecules from the surrounding environment, such as moisture in the ambient air, thereby allowing the water retaining layer 17 to accumulate water without being actively wetted by the user. In Figure 2b, the water retaining layer 17 is provided with a hygroscopic substance, such as a salt comprising calcium chloride or lithium chloride, for harvesting moisture from the surrounding air. An additional cover layer 19 may be provided around the housing 20, at least partly covering the water retaining layer 17 and preventing it from inadvertent touching by a user handling the hair roller 19. The cover layer 19 may be adapted to repel liquid water while allowing passage of water vapour (i.e., moisture to be captured from the air and released into the hair during heating). In different words, the cover layer 19 may be referred to as a waterproof, breathable membrane giving user, touching the cover layer 19, the impression of a dry surface. In the present example, the cover layer 19 comprises a non-woven propylene fabric. The cover layer 19 may be provided as a separate component that is fitted onto the water retaining layer 17, such as the sleeve, after the water retaining layer 17 has been arranged around the housing 20. Alternatively, the cover layer 19 may be attached to the water retaining layer 17 prior to mounting around the housing 20. The cover layer 19 and the water retaining layer 17 may hence form a composite structure that is attachable to the housing 20. In one test, a water retaining layer 17 comprising a fibrous absorption paper (0.22grams, 40 grams per square metre) was soaked in a calcium chloride solution (comprising 0.83grams calcium chloride and 1.55grams water) and wrapped around the housing 20 of the hair roller 10. Thereafter, a cover layer 19 of nonwoven polypropylene (27 grams per square metre) was wrapped around the water retaining layer 17. During the styling process, a tress of hair was wrapped onto the hair roller 10 and the roller 10 was heated. During heating, water in the water retaining layer 17 was found to evaporate and diffuse through the hair tress, thereby facilitating transfer of heat and moisture to the hair.

In a further example, a hydroscopic polymer film 17 formed of, e.g., konjac glucomannan (KGM) and hydroxypropyl (HPC) may be used as a hybrid polymer matrix holding a dispersed lithium chloride solution. The polymer film 17 may be sprayed onto the surface of the hair roller 10 wrapped by a cover layer 19 of waterproof, breathable fabric. The hydroscopic polymer film 17 may absorb water from the air and, when heated during styling, release the water as vapour.

In the embodiments shown in Figures 2a and b, the hair roller 10 comprises a circuit board 50 that supports circuitry connecting certain electrical components of the hair roller 10. Wire harnesses may be used to connect some components to each other and/or the circuit board. For instance, the temperature monitoring unit 34 may be wired to the circuit board.

The hair roller 10 comprises an electrical connector 18 as shown in Figures 1 and 2a-b. The electrical connector 18 is located at the first end 24 of the hair roller 10 but could be located in another suitable position on the hair roller 10. The electrical connector 18 is removably connectable to a supply of electrical energy external to the hair roller 10 so that electrical energy can be supplied to the hair roller 10 through the electrical connector 18 and then delivered to the electrically-powered heater to cause heating of the electrically-powered heater. The electrical connector 18 is electrically connected to the electrically-powered heater so that the supplied electrical energy can be delivered to the electrically-powered heater. Thus, the electrically-powered heater is powered by the external supply of electrical energy. In some embodiments, as shown in Figure 2, the electrical connector 18 is mounted on the circuit board 50, although the electrical connector may instead be separate component.

The electrical connector 18 is configured to cooperate with, and electrically connect with, an electrical supply connector through which electrical energy is deliverable to the electrical connector 18. In cooperating with one another, the electrical connector 18 and electrical supply connector may respectively comprise complementary male and female shapes that facilitate removably connecting the electrical connector 18 and electrical supply connector together. As explained further below, the electrical supply connector may be provided in an energy delivery device. The energy delivery device is configured such that the electrical energy can be supplied when the hair roller is inserted into a section of hair on a user’s head. The electrical connector 18 and electrical supply connector may comprise one or more electrical energy transfer pins through which the electrical energy can be transmitted. In some embodiments, the electrical connector 18 and electrical supply connector may comprise additional connector pins that provide for the transmission of other electrical signals, such as control signals that may be exchanged between the hair roller 10 and an energy delivery device as described herein and/or temperature control signals from the temperature monitoring unit 34.

Figure 3a schematically illustrates a cross-sectional view through an embodiment of a hair roller power applicator 100 according to the present invention. As also shown in Figure 3a, the hair roller power applicator 100 may be part of a hair roller kit 200, according to the present invention, and comprising at least one hair roller 10 as described herein and the hair roller power applicator 100. The hair roller kit 200 may comprise a plurality of hair rollers 10. The hair rollers 10 may be similarly configured as the ones discussed above with reference to Figures 2a and b.

The power applicator 100 is an energy delivery device and comprises a housing 120 that defines an enclosure 121 for containing and protecting certain components of the power applicator 100. The housing 120 has a shape that makes it easy for a user to handle the power applicator 100, for instance to apply electrical energy to a hair roller 10 as described further below. In this instance, the housing 120 has a generally cylindrical shape. The housing 120 may have a diameter of between 25mm and 50mm, for example to match the hair roller 10 diameter. The housing 20 may have a wall thickness of between 0.3mm and 2mm. The housing 20 may comprise a plastics material.

The power applicator 100 comprises an electrical supply connector 102. The electrical supply connector 102 is removably connectable and electrically engageable with the electrical connector 18 of the hair roller 10. For example, the electrical supply connector 102 may comprise a male shape that is connectable with a complementary female shape of the electrical connector 18 to form an electrical connection and electrical supply connector 102 together. Alternatively, the electrical supply connector 102 may comprise a female shape that is connectable with a complementary male shape of the electrical connector 18 to form an electrical connection and electrical supply connector 102 together. The power applicator 100 is configured so that electrical energy can be supplied to the electrical connector 18 through the electrical supply connector 102 when the hair roller 10 is inserted into the hair on a user’s head, for example when a section of the user’s hair is be wrapped around the housing 20 of the hair roller 10. The electrical supply connector 102 may be configured or shaped so that it is easy for a user to guide the electrical supply connector to connect with the electrical connector 18 when the hair roller 10 is on a user’s head, for instance where the hair roller 10 has been inserted into hair at the back of the user’s head. In one embodiment, the electrical supply connector 102 and/or the electrical connector 18 may comprise a magnet to aid the connecting of the electrical supply connector 102 to the electrical connector 18. Once the electrical connector 18 is electrically connected to the electrical supply connector 102, the electrical connector 18 can then receive the electrical energy from the electrical supply connector 102 for delivery to the electrically-powered heater.

The power applicator 100 comprises an electrical energy source located within the housing 120 and is arranged to, on demand, supply electrical energy to the electrical supply connector 102. The electrical energy source may be an AC or DC power supply. The power supply may be a low voltage power supply, for example less than 40V. The In the embodiment illustrated in Figure 3, electrical energy source is at least one battery 112 mounted within the enclosure 121 of the housing 120. There may be two or more batteries forming the electrical energy source. A battery holder is provided in the enclosure 121 to secure the battery 112. In one embodiment, the battery 112 is a high- voltage, high-capacity lithium-ion battery. The battery 112 may comprise a lithium-ion battery pack containing two, three, or four cells, or any suitable number of cells. The battery 112 may provide a voltage of 6V or higher. In one example, the battery 112 provides a voltage of 12V or higher. The battery 112 may have a capacity of at least 5000mAh. In one example, the battery 112 has a capacity of at least lOAh. The battery 112 may deliver at least 180W continuous power. In one example, the battery 112 delivers at least 350W continuous power.

Figure 3b schematically illustrates a cross-sectional view of a power applicator 100 and a hair roller 10, which may be similarly configured as the power applicator 100 and hair roller 10 in Figure 3a. The power applicator 100 however differs in that is comprises a heating rod 125 and a handle 126, by means of which a user can heat the hair roller 10 by thermal contact conductance rather than transfer of electrical energy to heaters of the hair roller 10. The housing 20 of the hair roller 10 may hence be configured as a hollow tube having an open end configured to receive the heating rod 125. It is understood that the heating rod 125 and the hollow interior of the tube-shaped housing 20 may be shaped and sized to allow the heating rod 125 to be fitted inside the housing 20. The rod 125 and the housing 20 may be form-fitted with each other to promote efficient thermal contact between the abutting surfaces, i.e., the interior surface of the hollow housing 20 and the exterior surface of the rod 20. The power applicator 100 in the present figure may also be referred to as a heating wand.

In the present example, each of the heating rod 125 and the housing 20 of the hair roller 10 is provided with matching frustum shapes, such as conical shapes, to facilitate insertion of the rod 125 and providing tight fit of the housing 20 on the rod 125. The rod 125 may hence be inserted into the housing 20 until the outer surface of the rod 125 abuts the inner surface of the hollow interior of the housing 20, thereby allowing for an improved heat transfer efficiency to the hair roller 10.

As mentioned above, the illustrated power applicator 100 comprises a handle 126 by which the power applicator 100 can be gripped and handled by the user. Further, the handle 126 comprises a control system 110. The control system 110 controls the supply of electrical energy to heating elements of the heating rod 125. The control system 110 also comprises a user interface 132 through which a user may interact with the control system 110 of the power applicator 100. The control system 110 and the user interface is discussed in further detail below. It will however be appreciated that it is also possible to arrange the control system 110, or parts thereof, such as the user interface 132, at a location separate from the handle 126. The user interface 132 may, for example, be arranged in a separate unit communicating with the heating rod 125 either wirelessly or by a wired communication channel.

The heating rod 125 forms a distal part of the power applicator 100 and the handle 126 a proximal part. The heating rod 125 may be configured to be detached from the handle 126 and replaced with differently sized rods 125 matching the size of the hair rollers 10 being used. Hence, a kit of parts may be provided, comprising a plurality of heating rods 125 that can be fitted with a handle 126 to form the power applicator 100. This allows for a more flexible power applicator 100 that is compatible with a broader variety of hair rollers 10.

As indicated in the present figure, the distal end portion of the heating rod 125 may have a rounded shape for facilitating insertion of the rod into the hollow interior of the hair roller 10.

The heating rod 125 is powered by a battery 112 as discussed above in connection with Figure 3a, which is arranged in the handle 126, or by means of a power supply cord that permits the power applicator 100 to be connected to a mains power supply (i.e. an electrical energy supply), for instance the mains power supply of a user’s residence or place of business, to provide the electrical energy source or deliver energy for the electrical energy source. A transformer may be used to bring voltage from mains voltage down, for instance to below 40V.

The hair roller 10 may comprise a hydrophobic coating 25. In an example, at least a portion of the inner surface of the housing 20 may be hydrophobic to reduce the amount of water accumulated on the surface and hence the amount of steam generated in the interface between the heating rod 125 and the inner surface of the hair roller 10. The coating may further be abrasion resistant to reduce wear as the hair roller is being used. The housing 20 may, for example, be formed of a thermally conductive sheet material, such as a 0.1mm thick copper sheet, which is rolled into a frustum shape or a cylinder having a length of about 70mm. In case of a frustum shape, the larger end may have a diameter of about 25mm and the smaller end a diameter of about 23mm.

The hydrophobic and possibly abrasion resistant coating may be provided on both sides or the housing 20, i.e., both in the inner surface and the outer surface of the hollow, tubular housing 20. In some embodiments, only the inner surface of the housing 20 is hydrophobic. In case the hair roller 10 comprises a water retaining layer 17 as described above, the water retaining layer 17 may be wetted by dipping the entire hair roll in water. The hydrophobic characteristics of the surface(s) of the housing may cause the water to concentrate to the water retaining layer 17 and reduce the amount of water present on the inside of the hair roller 10.

Examples of hydrophobic coatings include polymer-based coatings known in the art, such as the commercially available products Gentoo Coating (at the time of filing provided by UltraTech International, Inc.) and Nanomyte SuperCN (at the time of filing provided by NEI Corporation).

In one test, a hair roller 10 was formed of a 0.1mm thick copper sheet that was rolled into a frustum shaped hollow tube. A wet-laid pulp-based sheet material was used as a water retaining layer wrapped around the housing 20 of the hair roller 10. The hair roller was installed by wrapping a segment of a user’s hair around the housing 20. Thereafter, a shape matching heating rod 125 was heated to a set temperature of 200°C and inserted into the hair roller 10. Due to the latent heat of water, the surface of the water retaining material reached and maintained a temperature of 93 °C, whereas the temperature of the outer surface of the hair segment wrapped around the hair roller 10 reached a maximum of 53°C as the water was vapourised and penetrating the hair. After the heating rod 125 was removed from the hair roller 10, the hair was left on the roller and allowed to cool down for at least 3minutes or more to allow the hair roller 10 and hair to cool down.

It will be appreciated that other temperatures of the heating rod 125 also as possible. The heating rod can e.g. be maintained at a surface temperature of about 80°C. This may require longer heating times to reach the same hair temperature, such as heating times of 1 or 2 minutes or more.

It will further be appreciated that the heating of the roller 10 is not necessarily limited to heating rods 125 that are inserted into the housing 20, thus heating the hair roller 20 from the inside. On the contrary, the heat roller 10 may as well be heated by an electrically powered heater, removably connectable to a power applicator by means of an electrical connector as discussed above.

Figure 4 is a schematic diagram of the hair roller power applicator 100 according to the present invention. The power applicator 100 may for example be similarly configured as the embodiments illustrated in Figures 3a or b, and may hence comprise a housing 120 and an electrical supply connector 102 shown in Figure 3a, or a heating rod 125 and a handle 126 shown in Figure 3b.

According to the present embodiment, the power applicator 100 comprises a control system 110, which may be similarly configured as the one discussed above with reference to Figure 3b. The control system 110 may be configured to control the temperature of the heating rod 125 or the supply of electrical energy to the electrical supply connector 102 and thus to the electrically-powered heater. The control system 110 may further comprise a user interface 132 through which a user may interact with the control system 110 of the power applicator 100.

As shown in Figures 3a and b, the user interface 132 may be located on an outer surface of the power applicator 100. The user interface 132 may comprise a set of buttons that allow a user to select such control settings as heating duration and heating temperature for the heating rod 125 or the electrically-powered heater of the hair roller 10. For instance, the user interface 132 may comprise one or more of an on/off switch, a hair roller power application switch, heating temperature setting buttons, temperature indicators, timer selection buttons, and a display to convey information about the functional status of the hair roller 10 or the heating rod 125. In some embodiments, the user interface 132 comprises a graphical user interface.

As illustrated in Figure 4, the control system 110 may be connectable to the temperature monitoring unit 34, that may be part of the hair roller 10 or the heating rod 125. In other words, when the electrical connector 18 of the hair roller 10 in, e.g., Figures 2a-b and 3a is connected to the electrical supply connector 102, the temperature monitoring unit 34 is connected to the control system 110. The connection may be through the electrical supply connector 102. Signals from the temperature monitoring unit 34, such as a temperature measurement signal, may be delivered through the electrical supply connector 102 to the control system 110. The signals may be delivered through additional connector pins.

In embodiments in which the power applicator 100 comprises a heating rod 125, the temperature monitoring unit 34 may be arranged in the heating rod 125 instead of in the hair roller 10. Hence, it is understood that the electrical supply connector 102 shown in Figure 4 is an optional feature, which may be omitted in embodiments in which the hair roller 10 is heated by means of a heating rod 125 rather than by electrically-powered heaters arranged in the roller 10.

The control system may comprise a timer unit that is configured to control the duration for which electrical energy is supplied to the electrically-powered heater, or the duration for which the heating rod 125 is inserted in, or heating, the hair roller 10, thereby controlling the heating period of the hair roller. The user interface 132 may comprise a timer interface that allows the user to select the desired heating period. The timer unit may comprise a cut-off switch that opens and cuts off the supply of electrical energy to the heater once the heating period has elapsed. Alternatively, or additionally, the control system 110 may comprise a user indication system instructing the user to either switch off the heating or remove the power applicator, such as the heating rod 125, from the hair roller 10. The user indication may for example comprise tactile feedback, such as a vibrator, audible feedback, such as a buzzer, or a visual indicator.

In one embodiment, the user interface 132 is a power application switch in which placing the switch in an on position allows electrical energy to be supplied to the to the electrical supply connector 102 and thus to the electrically-powered heater. In another embodiment, the control system may comprise the power application switch and a connection to the thermal switch of the hair roller 10. In another embodiment, the control system comprises the power application switch, the thermal switch, and a timer cut-off switch. In a further embodiment, the power application switch controls the power supply to the heating rod 125.

As illustrated in Figure 4, the control system 110 may comprise a processor 136 that can execute instructions that cause the processor 136 to control certain functions of the power applicator 100, such as the supply of electrical energy to the electrical supply connector 102 (and thus the electrically-powered heater) from the battery 112, and the temperature of the heating rod 125, as well as the duration of the heating of the hair. The processor 136 may control and manage the battery 112. In some examples, the control system 110 comprises a storage module 138 that is encodable with instructions executable by the processor 136. The storage module 138 may comprise non-transitory machine-readable storage medium encoded with the instructions in machine readable form. The storage medium 138 may store additional data such as pre-determined desired heating temperatures and durations for hair. The storage medium 138 may store additional data such as desired heating temperatures and durations as set by a user through the user interface 132. The user interface 132 and, when a hair roller 10 is connected via the electrical supply connector 102, the temperature monitoring unit 34 may be connected to the processor 48 so that the processor 136 can send and receive signals to control the functions of the power applicator 100. The processor 136 may comprise timer modules, comparative temperature modules (to compare the actual temperature of the heater with a desired temperature), and electrical energy control (i.e. cut-off control) modules that control the function of the power applicator 100.

As shown in Figure 3a, the power applicator 100 may comprise a circuit board 150 that supports circuitry connecting certain electrical components of the power applicator 100. Wire harnesses may be used to connect some components to each other and/or the circuit board. For instance, the user interface may be wired to the circuit board.

The power applicator 100 may comprise a charging unit 116 that delivers and controls the flow of electrical energy to the battery 112, for recharging the battery 112, upon connection of a second electrical connector 118 to a charging connector. The charging unit 116 may supply electrical energy to the battery 112 as soon as an electrical connection is made between the second electrical connector 118 and the charging connector. In some embodiments, the control system 110 of the power applicator 100 may detect an electrical connection has been made between the second electrical connector 118 and the charging connector and then control the supply of electrical energy to the battery 112 through charging unit 116.

A charging device may be provided to charge the hair roller power applicator 100 when not in use. In some cases, the power applicator 100 and the charging device may be provided separately of any hair rollers 10. In other examples, the hair roller kit 200 may comprise the charging device, the power applicator 100, and a plurality of hair rollers 10. The charging device comprises a second electrical energy source to deliver electrical energy to the power applicator 100 to recharge the electrical energy source. The charging device comprises the charging connector, as described above, through which the electrical energy from the second electrical energy source is deliverable to the second electrical connector 118.

The charging device may be a docking station 300 as shown in Figure 5. Figure 5 is a schematic view of a hair roller kit 200 according to the present invention comprising a plurality of hair rollers 10, the power applicator 100, and a docking station 300. The docking station 300 comprises a receptacle 302 that is able to removably receive the power applicator 100 for charging. The receptacle 302 comprises a charging connector as described herein. The receptacle 302 may be configured to guide the power applicator 100 into a secure position and cause the second electrical connector 118 of the power applicator 100 to electrically engage with the charging connector. For example, the power applicator 100 may be inserted into the receptacle 302 so that the second electrical connector 118 electrically connects to the charging connector and can then receive the electrical energy from the charging connector. The docking station 300 may comprise a power supply cord 322 that permits the docking station 300 to be connected to a mains power supply (i.e. an electrical energy supply), for instance the mains power supply of a user’s residence or place of business, to provide the second electrical energy source. The second electrical energy source may be an AC power supply, for example. The docking station 300 may comprise a charging module that distributes electrical energy from the electrical energy supply to the charging connector.

In some embodiments, the docking station 300 may comprise a controller to control the functions of the docking station 300. The controller may comprise a processor that can execute instructions that cause the processor control certain functions of the docking station 300, such detecting the presence of the power applicator 100 in the receptacle and the supply of electrical energy to the charging connector. The controller may comprise a storage module that is encodable with instructions executable by the processor. The storage module may comprise non-transitory machine-readable storage medium encoded with the instructions in machine readable form. In certain embodiments, the controller may control the charging module to control delivery of electrical energy to the charging connector and therefore the delivery of electrical energy to the power applicator 100 for recharging the battery 112. Control signals may be exchanged between the control system 110 and the controller of the docking station 300 so that the control system 110 cooperates with the controller. In some embodiments, the controller of the docking station 300 may control the charging of the battery 112, for instance by controlling the charging unit 116 of the power applicator 100.

The docking station 300 comprises a plurality of docks 302 that are each able to removably receive one hair roller 10. The docking station 300 is also able to store the plurality of hair rollers 10 when not in use. For instance, the docking station 300 may include a lid, not shown in Figure 5, that secures the hair rollers 10 and the power applicator 100 in place in the docking station 300 when the hair rollers 10 are not in use. In one embodiment, each dock 302 comprises a socket into which a hair roller 10 may be inserted. The socket may be configured to guide the hair roller 10 into a secure docking position.

Figure 6 schematically illustrates a cross-sectional view through another embodiment of a hair roller power applicator 100 according to the present invention. As also shown in Figure 6, the hair roller power applicator 100 may be part of another embodiment of a hair roller kit 200, according to the present invention, comprising at least one hair roller 10 as described herein and the hair roller power applicator 100. The hair roller kit 200 may comprise a plurality of hair rollers 10.

The power applicator 100 is an energy delivery device and comprises a base unit 108 and a probe 104, which may comprise an electrical supply connector similar to the one in Figure 3 a or a heating rod 125 similar to the one inFigure 3b. Thebase unit 108 comprises a housing 120 that defines an enclosure 121 for containing and protecting certain components of the power applicator 100. The housing 20 may comprise a plastics material. As with the earlier described embodiment, the power applicator 100 may comprise a circuit board 150 to support certain electrical components and wire harnesses may be used to connect some components to each other and/or the circuit board. As already mentioned, the power applicator 100 may comprise an electrical supply connector 102 located in the probe 104, or a heating rod 125 configured to be inserted into the hair roller 10. The probe 104 is connected to the base unit 108 by a power supply cable 106. The probe 104 is therefore easily moved and manipulated, for instance around a user’s head, because the probe 104 is not weighed down by the bulkier base unit 108. The probe 104 has a shape that makes it easy for a user to handle the probe 104, for instance to apply electrical energy to a hair roller 10 as described further below. For instance, the probe 104 may have generally cylindrical shape or handle-like shape at one end and the electrical supply connector 102 located at the opposing end of the probe 104. The probe 104 may comprise a plastics material.

In some embodiments, the electrical supply connector 102 on the probe 104 is removably connectable and electrically engageable with the electrical connector 18 of the hair roller 10. In a similar manner to the previously described embodiment, the electrical supply connector 102 may comprise a male shape that is connectable with a female shape of the electrical connector 18 to form an electrical connection and electrical supply connector 102 together. The power applicator 100 is configured so that electrical energy can be supplied to the electrical connector 18 through the electrical supply connector 102 when the hair roller 10 is inserted into the hair on a user’s head. The electrical supply connector 102 may be configured or shaped so that it is easy for a user to guide the electrical supply connector 102 to connect with the electrical connector 18 when the hair roller 10 is on a user’s head, for instance where the hair roller 10 has been inserted into hair at the back of the user’s head. In one embodiment, the electrical supply connector 102 and/or the electrical connector 18 may comprise a magnet to aid the connecting of the electrical supply connector 102 to the electrical connector 18. Once the electrical connector 18 is electrically connected to the electrical supply connector 102, the electrical connector 18 can then receive the electrical energy from the electrical supply connector 102 for delivery to the electrically-powered heater.

The power applicator 100 comprises an electrical energy source located within the housing 120 and is arranged to, on demand, supply electrical energy to the electrical supply connector 102 through the power supply cable 106. The electrical energy source may be an AC or DC power supply. The power supply may be a low voltage power supply, for example less than 40V. In certain embodiments, the power applicator 100 may comprise a power supply cord 122 that permits the power applicator 100 to be connected to a mains power supply (i.e. an electrical energy supply), for instance the mains power supply of a user’s residence or place of business, to provide the electrical energy source or deliver energy for the electrical energy source. A transformer may be used to bring voltage from mains voltage down, for instance to below 40V. In some embodiments, as illustrated in Figure 6, the electrical energy source can comprise at least one battery 112 mounted within the enclosure 121 of the housing 120. The at least one battery 112 can be charged from the mains power supply so that the power applicator 100 can be used in a variety of settings, such as when a mains power supply is temporarily unavailable. It will be understood that the electrical energy source may comprise one or other of the mains power supply or the battery, or a combination of both of these. In one embodiment, the battery 112 is a high-voltage, high-capacity lithium-ion battery. The battery 112 may comprise a lithium-ion battery pack containing two, three, or four cells, or any suitable number of cells. The battery 112 may provide a voltage of 6V or higher. In one example, the battery provides a voltage of 12V or higher. The battery 112 may have a capacity of at least 5000mAh. In one example, the battery 112 has a capacity of at least lOAh. The battery 112 may deliver at least 180W continuous power. In one example, the battery 112 delivers at least 350W continuous power.

Referring also to Figure 7, which is a schematic diagram of the hair roller power applicator 100 according to some embodiments of the present invention, the power applicator 100 comprises a control system 110. The control system 110 controls the supply of electrical energy to the electrical supply connector 102 and thus to the electrically-powered heater. The control system 110 comprises a user interface 132 through which a user may interact with the control system 110 of the power applicator 100. As shown in Figures 3a and b, the user interface 132 may be located outer surface of the power applicator 100. The user interface 132 may comprise a set of buttons that allow a user to select such control settings as heating duration and heating temperature for the electrically-powered heater of the hair roller 10. For instance, the user interface 132 may comprise one or more of an on/off switch, a hair roller power activation switch, heating temperature setting buttons, temperature indicators, timer selection buttons, and a display to convey information about the functional status of the hair roller 10. In some embodiments, the user interface 132 comprises a graphical user interface.

As with the embodiment described hereinbefore, the control system 110 may comprise a connection to the temperature monitoring unit 34 that may be part of the hair roller 10 or the heating rod 125. As illustrated in Figure 7, the connection may be through the electrical supply connector 102. Signals from the temperature monitoring unit 34, such as a temperature measurement signal, may be delivered through the electrical supply connector 102 to the control system 110.

The control system may comprise a timer unit that is configured to control the duration for which electrical energy is supplied to the electrically-powered heater thereby controlling the heating period of the hair roller. The user interface 132 may comprise a timer interface that allows the user to select the desired heating period. The timer unit may comprise a cut-off switch that opens and cuts off the supply of electrical energy to the heater or the heating rod 125 once the heating period has elapsed. In an embodiment, the timer unit is configured to trigger the generation of a signal to the user, indicating that the user may remove the power applicator 100 from the hair roller 10 or cut off the supply of electrical energy to the electrically-powered heater or heating rod. The signal may be a tactile signal, an audible signal, or a visual signal.

In one embodiment, the user interface 132 is a power activation switch in which placing the switch in an on position allows electrical energy to be supplied to the to the electrical supply connector 102 and thus to the electrically-powered heater or, in case the power applicator 100 is a heating wand, to the heating rod. As illustrated in Figures 6 and 7, the power activation switch 133 may be located on the probe 104 so a user can easily activate the power supply to the hair roller 10. In another embodiment, the control system may comprise the power activation switch and a connection to the thermal switch of the hair roller 10. In another embodiment, the control system comprises the power activation switch, the thermal switch, and a timer cut-off switch.

As with the embodiment described hereinbefore, and as illustrated in Figure 7, the control system 110 may comprise a processor 136 that can execute instructions that cause the processor 136 control certain functions of the power applicator 100, such as the supply of electrical energy to the electrical supply connector 102 from the mains supply or the battery 112. In some examples, the control system 110 comprises a storage module 138 that is encodable with instructions executable by the processor 136. The storage medium 138 may also store additional data such as that described previously herein. The user interface 132 and the temperature monitoring unit 34 may be connected to the processor 48 so that the processor 136 can send and receive signals to control the functions of the power applicator 100. The processor 136 may comprise various modules as described previously herein

Where necessary, the power applicator 100 may comprise a charging unit 116 that delivers and controls the flow of electrical energy to the battery 112, for recharging the battery 112. The charging circuit 116 may supply electrical energy to the battery 112 from the mains supply, for instance when the power applicator 100 is not in use. In some embodiments, the control system 110 may control the charging of the battery 112, for instance by controlling the charging unit 116 of the power applicator 100.

The base unit 108 may be a docking station as shown in Figure 8. Figure 8 is a schematic view of a hair roller kit 200 according to the present invention comprising a plurality of hair rollers 10 and the power applicator 100. The base unit 108 comprises a receptacle 124 that can removably receive the probe 104 for storage purposes. The base unit 108 comprises a plurality of docks 102 that are each able to removably receive one hair roller 10. The base unit 108 is also able to store the plurality of hair rollers 10 when not in use. For instance, the base unit 108 may include a lid, not shown in Figure 8, that secures the hair rollers 10 and the power applicator 100 in place in the base unit 108 when the hair rollers 10 are not in use. In one embodiment, each dock 102 comprises a socket into which a hair roller 10 may be inserted. The socket may be configured to guide the hair roller 10 into a secure docking position.

As noted above, the hair roller 10 may one of a plurality of hair rollers 10. A user may use one, or any desired number of, hair rollers 10 to shape hair. In use, a user wraps a section of hair around the hair roller 10. Where present, the bristles 28 help to hold the section of hair in place on the hair roller 10. Where present, the fibrous material helps to hold the section of hair in place on the hair roller 10. Where present, water has been added to a water retaining layer 17 of the hair roller 10. In some cases, the user my use a clip to secure the section of hair to the hair roller 10. The hair roller 10 may be cold and, in some cases, wetted when inserted into the hair. The hair roller 10 may be one of a plurality of hair rollers 10 that the user inserts into the hair. The user then heats the hair roller 10 either by connecting the electrical supply connector 102 of the power applicator 100 to the electrical connector 18 of the hair roller 10 to deliver electrical energy from the electrical supply connector 102 to the electrically-powered heater of the hair roller 10, or by inserting a heater rod 125 of the power applicator 100 into a hollow interior of the hair roller 10. In embodiments wherein the hair roller 10 comprises a water retaining layer 17, water contained in the water retaining layer 17 may evaporate to moisturise and heat the hair.

In the embodiments where the heat is provided via the heater rod 125 or where the electrical supply connector 102 is in the probe 104, the heater 125 or probe 104 are manoeuvrable around a user’s head therefore making it easy to deliver the heat or electrical energy to a hair roller 10 on the user’s head. In the embodiment where the electrical supply connector 102 is in the battery powered power applicator 100 as shown in Figures 3a, 4 and 5, there is no power cable restricting the delivery of the electrical energy to a hair roller 10 on the user’s head. The user may use the power applicator 100 once all hair rollers 10 are inserted into the hair or after each of the hair rollers 10 are inserted. Once connected, and where a further activation process is used, such as turning on the power application switch, the electrical energy source supplies electrical energy to the heater.

Once the hair roller 10 has been heated, the electrical supply connector 102 can be separated from the electrical connector 18. The power applicator 100 can then be used on another hair roller 10, if desired. Similarly, in case the power applicator 100 comprises a heating rod 125, the heating rod 125 can be removed from the hair roller 10 once the hair roller 10 has been heated.

In embodiments wherein the hair rollers 10 comprises electrically-powered heaters, the electrical energy may be supplied to provide a predetermined heating profile over a heating period. For example, the predetermined heating profile may comprise heating each hair roller 10 by delivering the electrical energy through the electrical supply connector 102 to heat each respective electrically powered heater for between 5s and 12s. For instance, each hair roller 10 can be heated to between 80°C and 125°C for between approximately 10 seconds and 20 seconds. Once heated and the electrical supply connector 102 is separated from the electrical connector 18, the hair roller 10 retains residual heat that continues to heat the section of hair for a period as the hair roller 10 cools down.

In embodiments wherein the hair rollers 10 are configured to be heated by a heating rod 125 inserted into their hollow interior, the heat may be supplied to each hair roller 10 to provide a predetermined heating profile over a heating period. For example, the predetermined heating profile may comprise heating each hair roller 10 by allowing the heating rod 10 to be inserted in the hair roller 10 for between 5s and 15s. For instance, each hair roller 10 can be heated to between 80°C and 100°C for between approximately 10 seconds and 20 seconds. Once heated and the heating rod 125 is removed from the hair roller 10, the hair roller 10 may retain residual heat that continues to heat the section of hair for a period as the hair roller 10 cools down. The presence of water in the water retaining layer 17 allows for even higher roller temperatures to be used without overheating the hair. In an experiment, the housing of the hair roller 10 was heated to a temperature between 200°C and 230°C, while the temperature at the contact interface between the water retaining layer 17 and the hair was maintained below 100°C due to the latent heat of the liquid water. The relatively high temperature of the housing was observed to increase the evaporation rate of the water and hence the pressure of the generated vapour. The increased evaporation rate and pressure, in turn, resulted in a more efficient vapour penetration of the hair layers wrapped around the roller 10.

The user may wait to remove the hair roller 10 until the hair roller 10 cools down over a cooling period that commences once the heating period has elapsed and the supply of electrical energy is disconnected from the electrically-powered heater, or the heating rod 125 is removed from the hair roller 10. For example, the user may wait between 10 and 20 minutes before removing the hair roller 10 from the hair. In one test, it was found that a hair roller 10 wrapped with a 6 grams’ section of hair, which was 360mm long and 30mm wide, could be heated to 120°C in 10s by applying 270W of power (DC) to the electrically-powered heater of the hair roller 10. After leaving the hair roller 10 in the section of hair for 10 minutes, a good curl was produced.

The control system 110 may control the supply of electrical energy to heat the electrically- powered heater thereby providing the predetermined heating profile over the heating period. In some embodiments, the control system 110 may control the temperature or heating of the heating rod 125. For instance, the control system 110 may control the supply of electrical energy to the heating rod 125 or the electrically-powered heater to deliver a certain power level to cause heating over a certain heating period.

For the embodiment of the power applicator 100 shown in Figures 3 to 5, a user may insert the power applicator 100 into the receptacle 302 thereby connecting the second electrical connector 118 of the power applicator 100 with the corresponding charging connector of the docking station 300. Upon electrical connection, electrical energy may be supplied through the second electrical connector 118 to recharge the battery 112 as described herein. The user may insert the power applicator 100 into the receptacle 302, for example, after treating hair with the hair rollers 10. The docking station 300 may be provided with an indicator that indicates when the power applicator 100 is present in the receptacle 302 and the battery 112 of the power applicator 100 is charging. In another embodiment, the user interface 132 of the power applicator 100 may comprise an indicator that indicates when the battery 112 of power applicator 100 is charging. Once charged, a user may remove the power applicator 100 from the receptacle 302 and apply electrical energy to a hair roller 10 to shape a section of hair wrapped around the hair roller 10 to shape the section of hair.

The invention is not limited to the detailed description given above. Variations will be apparent to the person skilled in the art.