EP3166442B1

EP3166442B1 - Applicator with a heating member for applying a cosmetic product on keratinous fibers

Info

Publication number: EP3166442B1
Application number: EP15734705.5A
Authority: EP
Inventors: Nicolas Duru; Frédéric Jollet
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2014-07-11
Filing date: 2015-07-10
Publication date: 2018-06-06
Anticipated expiration: 2035-07-10
Also published as: FR3023457A1; CN106659285A; JP2017519605A; JP6324611B2; KR20170012563A; WO2016005567A1; FR3023457B1; EP3166442A1; US20170196340A1

Description

The present invention relates to an applicator for applying a cosmetic product on keratinous fibers, the applicator comprising a gripping member, a tip attached to the gripping member, and a member for applying the cosmetic product intended to be rigidly connected to the tip during the application of the cosmetic product, the tip comprising a heating member for heating the application member so as to enable the application of the cosmetic product on keratinous fibers, and a source of electricity for electrically powering the heating member and inducing a temperature rise of the heating member, a unit for controlling the source of electricity, at least a first temperature sensor suitable for supplying the unit with at least a first parameter representative of the temperature of the heating member or of the tip. An example of such an applicator can be found in document FR2999886 . The cosmetic product is for example a mascara, a care product, or a cleansing product.
By "cosmetic product", in the sense of this invention, we more generally mean a product as defined in EC Regulation n°1222/2009 of the European Parliament and the Council of November 30, 2009, relating to cosmetic products.
The application member is for example a removable comb comprising the cosmetic product to be applied.
A user seeking to use the applicator activates the source of electricity to electrically power the heating member. This induces a temperature rise therein. The control unit serves to regulate the temperature of the heating member so as to reach a target temperature. The cosmetic product contained in the application member is heated by conduction, enabling the application thereof on keratinous fibers.
However, if the user omits to place the application member on the tip and nonetheless activates heating, electricity consumption takes place at a loss.
Similarly, if the application member is for example a pin intended to be extended into a reservoir containing the cosmetic product, and the user activates heating, the source of electricity is used at a loss.
The use of the source of electricity at a loss reduces the service life or the autonomy in terms of power of the applicator.
One aim of the invention is thus that of providing an applicator having an enhanced service life or autonomy in terms of power.
To this end, the invention relates to an applicator of the type described above, wherein the unit is suitable for producing, on the basis of the first parameter, a second parameter representative of the rate of the temperature rise of the heating member, and comparing the second parameter to at least one threshold value stored in memory in the unit and, on the basis of the result of the comparison, switching off the electrical power supply of the heating member.
According to particular embodiments of the invention, the applicator comprises one or several of the following features taken in isolation or in any technically possible combination:

the threshold value is an upper threshold, and the unit is suitable for detecting whether the second parameter is greater than or equal to the upper threshold, and, if so, switching off the electrical power supply of the heating member.
the threshold value is a lower threshold, and the unit is suitable for detecting whether the second parameter is less than or equal to the lower threshold, and, if so, switching off the electrical power supply of the heating member.
the second parameter is taken from a derivative of the first parameter over time, a value of the first parameter adopted by the first parameter after a given time during which the heating member is powered by the source of electricity, a time taken by the first parameter to reach a given value, or a time constant of the temperature rise of the heating member, or combinations thereof, particularly linear combinations thereof.
it comprises a second temperature sensor suitable for measuring at least a third parameter, the third parameter being representative of the ambient temperature when the application member is not rigidly connected to the tip, the second parameter being computed by the unit using the first parameter and the third parameter.
the second temperature sensor is situated substantially at a distal end of the tip relative to the gripping member.
it further comprises a thermal insulator situated longitudinally between the second temperature sensor and the heating member.
the application member is removable, and preferably has a comb general shape.
it comprises a reservoir suitable for receiving the cosmetic product, the application member being movable between an idle position, wherein the application member is situated in the reservoir, and a use position, wherein the application member is situated outside the reservoir, the application member preferably having a general brush shape.

The invention also relates to a method for applying a cosmetic product on keratinous fibers, the method comprising at least the following steps:

providing an applicator comprising: a gripping member; a tip attached to the gripping member; a member for applying the cosmetic product intended to be rigidly connected to the tip during the application of the cosmetic product, the tip comprising a heating member; a source of electricity; a unit for controlling the source of electricity; and at least a first temperature sensor,
supplying electrical power to the heating member by means of the source of electricity to induce a temperature rise of the heating member,
heating the cosmetic product by means of the heating member so as to enable the application of the cosmetic product on keratinous fibers,
supplying the unit, by means of the first temperature sensor, with at least a first parameter representative of the temperature of the heating member,
producing by means of the unit, on the basis of the first parameter, a second parameter representative of the rate of the temperature rise of the heating member, and
comparing, by means of the unit, the second parameter to at least one threshold value stored in memory in the unit, and, on the basis of the result of the comparison, switching off the electrical power supply of the heating member by the unit.

The invention will be easier to understand in view of the following description, provided solely as an example and with reference to the appended drawings, wherein:

figure 1 is a perspective view showing the external appearance of an applicator according to a first embodiment of the invention,
figure 2 is a cross-sectional view schematically representing the applicator shown in figure 1
figure 3 is a graph illustrating the temperature rise of the heating member of the applicator represented in figures 1 and 2,
figure 4 is a schematic, cross-sectional view of an applicator according to a second embodiment of the invention, and
figure 5 is a graph illustrating the temperature rise of the heating member of the applicator represented in figure 4,

With reference to figures 1 and 2, an applicator 1 according to the invention is described. The applicator 1 is intended to apply a cosmetic product (not shown) on keratinous fibers (not shown), for example eyelashes, of a recipient (not shown). In general, the recipient is the user of the applicator 1.
The applicator 1 has for example an elongated shape along a longitudinal direction L.
The applicator 1 comprises a base acting as a gripping member 5, a tip 10 attached to the gripping member, and an application member 15 suitable for applying the cosmetic product. The applicator 1 further comprises a source of electricity 20 (figure 2) for electrically powering a heating member 25, a unit 30 for controlling the source of electricity, and at least a first temperature sensor 35 suitable for supplying the unit 30 with at least a first parameter T representative of the temperature of the heating member.
Optionally, the applicator 1 also comprises a second temperature sensor 40 and a thermal insulator 45, advantageously situated at a distal end of the tip 10.
The cosmetic product is for example a mascara.
The gripping member 5 is suitable for handling by the user. The gripping member 5 comprises for example two half-shells assembled together and made of plastic.
The gripping member 5 advantageously comprises an on-off button 47. In the example shown, the gripping member 5 also comprises an operating light 49, for example a light-emitting diode.
The tip 10 has for example a general tubular shape. The tip 10 advantageously comprises a metal tube 51. The tip 10 extends for example along the longitudinal direction L. The tip 10 comprises a proximal end 53 relative to the gripping member 5.
The proximal end 53 is attached to the gripping member 5.
The metal tube 51 comprises for example an open distal end 55.
The application member 15 is advantageously removable. The application member 15 is movable between a position wherein it is removed from the tip 10 (figure 1), and an application position (figure 2) wherein the application member is connected to the tip 10. For example, the application 15 is attached to the tip 10 in the application position.
According to further embodiments not shown, the application member 15 is connected to the tip 10 by any means known to those skilled in the art. For example, the application member 15 is rotatably mounted on the tip 10, advantageously about the longitudinal direction L.
The application member 15 has for example a general comb shape. The application member 15 comprises teeth 57 suitable for applying the cosmetic product on keratinous fibers.
The application member 15 defines an inner recess suitable for receiving the tip 10 longitudinally in the application position.
The teeth 57 are advantageously oriented substantially radially from the longitudinal direction L. For example, the teeth 57 extend in a half-space defined by a median plane P of the application member 15.
The source of electricity 20 is for example a battery, advantageously rechargeable. The source of electricity 20 is advantageously situated inside the gripping member 5.
The source of electricity 20 is suitable for delivering a rated electrical power between 0.5 and 2 W.
The first temperature sensor 35 is for example a thermocouple.
According to alternative embodiments not shown, the first temperature sensor 35 is a Hall effect sensor or a switch.
The first temperature sensor 35 is for example situated inside the tip 10. The first temperature sensor 35 is advantageously situated in the vicinity of the heating member 25, i.e. for example at a distance from the heating member 25 less than 10 mm.
According to one advantageous embodiment, the first temperature sensor 35 is situated on the heating member 25.
The first parameter T representative of the temperature of the heating member 25 is advantageously the temperature of the heating member.
The heating member 25 is for example a resistive printed circuit board (PCB). The heating member 25 is electrically connected to the source of electricity 20.
The unit 30 is suitable for producing, on the basis of the first parameter T, a second parameter T1 or T2 (figure 3) representative of the rate of the temperature rise of the heating member 25. The heating member 25 extends longitudinally inside the tip 10. Advantageously, the heating member 25 has longitudinally an extension E substantially equal to that of the application member 15.
The unit 30 is also suitable for comparing the second parameter T1 or T2 to at least one threshold value Tmax stored in memory in the unit 30 and, on the basis of the result of the comparison, switching off the electrical power supply of the heating member 25 by the source of electricity 20.
In the example shown in figures 1 to 3, the threshold value Tmax is an upper threshold. The unit 30 is suitable for detecting whether the second parameter T1 or T2 is greater than or equal to the upper threshold, and, if so, switching off the electrical power supply of the heating member 25 by the source of electricity 20. Tmax is for example equal to approximately 55°C.
Again in the example represented in figure 3, the second parameter is for example defined as being a value of the first parameter T adopted by the first parameter after a given time during which the heating member 25 is electrically powered by the source of electricity 20. For example, the given time is 10 seconds.
According to further embodiments not shown, the second parameter is taken from: a derivative of the first parameter T over the time t, a time taken by the first parameter T to reach a given value, or, more generally, a time constant of the temperature rise of the heating member 25 at the start of heating.
According to one particular embodiment, the second parameter is a combination of the possibilities cited above, particularly a linear combination.
The second temperature sensor 40 is situated substantially at the distal end 55 of the metal tube 51 relative to the gripping member 5.
The second temperature sensor 40 is suitable for supplying the ambient temperature when the application member 15 is not present. When the application member 15 is in place, the temperature is slightly higher by approximately 4 degrees, due to more limited heat exchanges with the ambient. This is a second, less preferential, way of detecting the presence or absence of the application member 15.
The thermal insulator 45 is for example made of elastomer. The insulator 45 is situated longitudinally between the second temperature sensor 40 and the heating member 25.
The operation of the applicator 1 shall now be described.
To use the applicator 1, a user moves the application member 15 from the removed position represented in figure 1, to the application position represented in figure 2. The application member 15 is then in contact with the tip 10, in the vicinity of the heating member 25.
Then, the user presses the switch 47 to activate the electrical power supply of the heating member 25 from the source of electricity 20. This induces a temperature rise of the heating member 25, illustrated by a curve C1 in the graph in figure 3.
This graph shows the progression of the first parameter T, i.e. in this case the temperature of the heating member 25, as a function of the time t.
The cosmetic product contained in the application member 15 is heated by the heating member 25, enabling the application of the cosmetic product on keratinous fibers.
The first temperature sensor 35 measures the first parameter T and supplies same to the unit 30.
The unit 30, on the basis of the first parameter T, produces the second parameter T1 representative of the rate of the temperature rise of the heating member 25. The second parameter T1 is at the value of the first parameter T after 10 seconds for example. T1 is for example equal to approximately 50°C.
Then, the unit 30 compares the second parameter T1 to the threshold value Tmax, which is in this case an upper threshold. If the second parameter T1 is less than or equal to the threshold value Tmax, the unit 30 does not switch off the electrical power supply of the heating member 25 by the source of electricity 20. This is the case here, as T1 is 5°C less than Tmax.
The unit 30 further advantageously carries out a regulation function, known per se, enabling the first parameter T to reach a target temperature Tc. Tc is for example equal to approximately 80°C.
In this regulation function, the unit 30 is optionally required to switch off or modify the electrical power supply of the heating member 25, but the unit does not do so on the basis of a parameter representative of the temperature rise of the heating member 25 following the start-up of the applicator 1.
However, if the user omits to place the application member 15 on the tip 10 before use, the temperature rise of the member 25 recorded by the temperature sensor 35 is represented by a curve C2. The curve C2 shows a more rapid temperature rise than that of the curve C1 due to the lack of thermal dissipation of the heat generated by the heating member 25 in the application member 15.
In this case, the second parameter produced by the unit 30 adopts a value T2 greater than the threshold value Tmax. The unit 30 then switches off the electrical power supply of the heating member 25. Once again, this switching off is not suitable for regulating the first parameter T, but results from a comparison of the second parameter, representative of the rate of the temperature rise of the heating member 25, with a threshold value.
By means of the features described above, the applicator 1 is capable of detecting the absence of the application member 15 in contact with the tip 10, and of switching off the electrical power supply of the heating member 25. This makes it possible to prevent unnecessary heating by the heating member 25, and thus enhance the service life of the autonomy in terms of power of the application 1.
In addition, this also makes it possible to prevent the tip 10 from reaching a relatively high temperature potentially causing burning of the user if the latter were to apply the tip 10 directly onto keratinous fibers.
A further way of detecting the presence or absence of the application member 15 is that of measuring the difference in temperature between the ambient temperature and a reference temperature at the second temperature sensor 40. The reference temperature is the expected temperature in the absence of the application member 15. The temperature variation observed in the presence of the application member 15 is slight, in the region of approximately 4 degrees. For this reason, this method is not preferential.
With reference to figures 4 and 5, an applicator 100 according to a second embodiment of the invention is described. The applicator 100 is similar to the applicator 1 represented in figures 1 and 2. Similar elements bear the same reference numbers and shall not be described a second time. Only the differences shall be described hereinafter.
The applicator 100 comprises a reservoir 101 suitable for receiving the cosmetic product, for example a mascara.
The application member 15 is movable between an idle position (figure 4) wherein the application member is situated in the reservoir 101, and a use position (not shown) wherein the application member is situated outside the reservoir and which is suitable for applying the cosmetic product onto keratinous fibers.
The application member 15 has for example a general brush shape. The application member 15 comprises bristles 157 oriented substantially radially from the longitudinal direction L. The bristles 157 are for example distributed at an angle about the longitudinal direction L in a substantially regular manner.
The applicator 100 comprises a heating member 125 having a filament shape wound around the application member 15, for example in a spiral.
In the idle position, the gripping member 5 is for example screwed onto the reservoir 101.
The tip 10 has for example a rod shape.
In the example, the application member 15 is not removable. The application member 15 is advantageously situated at the end of the tip 10.
The operation of the applicator 100 shall now be described.
With reference to figure 5, the temperature sensor 35 of the applicator 100 supplies the first parameter T representative of the temperature of the heating member 125.
During normal use, i.e. when the application member 15 is in the use position, the temperature rise takes place according to a curve C3 seen in figure 5.
The unit 30 produces a second parameter T1, which is in the example the value adopted by the first parameter T after 10 seconds. The unit 30 compares the second parameter T1 to a threshold value Tmin, which is in this case a lower threshold.
T1 is for example equal to 50°C.
Tmin is for example equal to 40°C.
If the second parameter T1 is greater than or equal to the threshold value Tmin, which is the case herein, the unit 30 does not switch off the electrical power supply of the heating member 125. The temperature rise continues and the unit 30 carries out the function thereof for regulating the first parameter T at the target value Tc.
However, if the user activates heating while the application member 15 is in the idle position thereof, i.e. in the reservoir 101, the temperature rise, represented by a curve C4 in the figure 5, is much slower, or even non-existent.
The unit 30 produces a second parameter T2 which is then less than the value Tmin. The control unit 30 switches off the electrical power supply of the heating member 125 by the source of electricity 20.
T2 is close to the ambient temperature and for example is equal to approximately 25°C. By means of the features described above, the applicator 100 is suitable for preventing unnecessary heating of the heating member 125.

Claims

Applicator (1; 100) for applying a cosmetic product on keratinous fibers; the applicator (1; 100) comprising:
- a gripping member (5), a tip (10) attached to the gripping member (5), and a member (15) for applying the cosmetic product intended to be rigidly connected to the tip (10) during the application of the cosmetic product, the tip (10) comprising a heating member (25; 125) for heating the application member (15) so as to enable the application of the cosmetic product on keratinous fibers, and

- a source of electricity (20) for electrically powering the heating member (25; 125) and inducing a temperature rise (C1, C2, C3, C4) of the heating member (25; 125), a unit (30) for controlling the source of electricity (20), at least a first temperature sensor (35) suitable for supplying the unit (30) with at least a first parameter (T) representative of the temperature of the heating member (25; 125) or of the tip (10),
characterized in that the unit (30) is suitable for:
- producing, on the basis of the first parameter (T), a second parameter (T1, T2) representative of the rate of the temperature rise (C1, C2, C3, C4) of the heating member (25; 125), and

- comparing the second parameter (T1, T2) to at least one threshold value (Tmax, Tmin) stored in memory in the unit (30) and, on the basis of the result of the comparison, switching off the electrical power supply of the heating member (25; 125).
Applicator (1; 100) according to claim 1, characterized in that:
- the threshold value (Tmax) is an upper threshold, and

- the unit (30) is suitable for detecting whether the second parameter (T1, T2) is greater than or equal to the upper threshold, and, if so, switching off the electrical power supply of the heating member (25; 125).
Applicator (1; 100) according to claim 1 or 2, characterized in that:
- the threshold value (Tmin) is a lower threshold, and

- the unit (30) is suitable for detecting whether the second parameter (T1, T2) is less than or equal to the lower threshold, and, if so, switching off the electrical power supply of the heating member (25; 125).
Applicator (1; 100) according to any one of claims 1 to 3, characterized in that the second parameter (T1, T2) is taken from:
- a derivative of the first parameter (T) over time (t),

- a value of the first parameter (T) adopted by the first parameter (T) after a given time during which the heating member (25; 125) is powered by the source of electricity (20),

- a time taken by the first parameter (T) to reach a given value, or

- a time constant of the temperature rise (C1, C2, C3, C4) of the heating member (25; 125), or

- combinations thereof, particularly linear combinations thereof.
Applicator (1) according to any one of claims 1 to 4, characterized in that it comprises a second temperature sensor (40) suitable for measuring at least a third parameter, the third parameter being representative of the ambient temperature when the application member (15) is not rigidly connected to the tip (10), the second parameter (T1, T2) being computed by the unit (30) using the first parameter (T) and the third parameter.
Applicator (1) according to claim 5, characterized in that the second temperature sensor (40) is situated substantially at a distal end (55) of the tip (10) relative to the gripping member (5).
Applicator (1) according to claim 5 or 6, characterized in that it further comprises a thermal insulator (45) situated longitudinally between the second temperature sensor (40) and the heating member (25).
Applicator (1) according to any one of claims 1 to 7, characterized in that the application member (15) is removable, and preferably has a comb overall shape.
Applicator (100) according to any one of claims 1 to 8, characterized in that it comprises a reservoir (101) suitable for receiving the cosmetic product, the application member (15) being movable between an idle position, wherein the application member (15) is situated in the reservoir (101), and a use position, wherein the application member (15) is situated outside the reservoir (101), the application member (15) preferably having a general brush shape.
Method for applying a cosmetic product on keratinous fibers, the method comprising at least the following steps:
- providing an applicator (1; 100) comprising: a gripping member (5); a tip (10) attached to the gripping member (5); a member (15) for applying the cosmetic product intended to be rigidly connected to the tip (10) during the application of the cosmetic product, the tip (10) comprising a heating member (25; 125); a source of electricity (20); a unit (30) for controlling the source of electricity (20); and at least a first temperature sensor (35),

- supplying electrical power to the heating member (25; 125) by means of the source of electricity (20) to induce a temperature rise of the heating member (25; 125),

- heating the cosmetic product by the heating member (25; 125) so as to enable the application of the cosmetic product on keratinous fibers,

- supplying the unit (30), by means of the first temperature sensor (35), with at least a first parameter (T) representative of the temperature of the heating member (25; 125),

- producing by the unit (30), on the basis of the first parameter (T), a second parameter (T1, T2) representative of the rate of the temperature rise (C1, C2, C3, C4) of the heating member (25; 125), and

- comparing, by the unit (30), the second parameter (T1, T2) to at least one threshold value (Tmax, Tmin) stored in memory in the unit (30), and, on the basis of the result of the comparison, switching off the electrical power supply of the heating member (25; 125) by the unit (30).