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

Abstract

The invention relates to an applicator ( 1 ) comprising: a gripping member ( 5 ), a tip ( 10 ) attached to the gripping member ( 5 ), and an application member ( 15 ), the tip ( 10 ) comprising a heating member ( 25 ) for heating the application member ( 15 ), and a source of electricity ( 20 ) for powering the heating member ( 25 ), a unit ( 30 ) for controlling the source of electricity ( 20 ), a first temperature sensor ( 35 ), characterized in that the unit ( 30 ) 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 ( 25 ), and comparing the second parameter to at least one threshold value 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 ).

1 . 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 (C 1 , C 2 , C 3 , C 4 ) 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 (T) representative of the temperature of the heating member or of the tip,   
       wherein the unit is suitable for:
 producing, on the basis of the first parameter (T), a second parameter (T 1 , T 2 ) representative of the rate of the temperature rise (C 1 , C 2 , C 3 , C 4 ) of the heating member, and 
 comparing the second parameter (T 1 , T 2 ) to at least one threshold value (Tmax, Tmin) 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. 
 
     
     
         2 . Applicator according to  claim 1 , wherein:
 the threshold value (Tmax) is an upper threshold, and   the unit is suitable for detecting whether the second parameter (T 1 , T 2 ) is greater than or equal to the upper threshold, and, if so, switching off the electrical power supply of the heating member.   
     
     
         3 . Applicator according to  claim 1 , wherein:
 the threshold value (Tmin) is a lower threshold, and   the unit is suitable for detecting whether the second parameter (T 1 , T 2 ) is less than or equal to the lower threshold, and, if so, switching off the electrical power supply of the heating member.   
     
     
         4 . Applicator according to  claim 1 , wherein the second parameter (T 1 , T 2 ) 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 is powered by the source of electricity,   a time taken by the first parameter (T) to reach a given value, or   a time constant of the temperature rise (C 1 , C 2 , C 3 , C 4 ) of the heating member, or   combinations thereof, particularly linear combinations thereof.   
     
     
         5 . Applicator according to  claim 1 , which 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 (T 1 , T 2 ) being computed by the unit using the first parameter (T) and the third parameter. 
     
     
         6 . Applicator according to  claim 5 , wherein the second temperature sensor is situated substantially at a distal end of the tip relative to the gripping member. 
     
     
         7 . Applicator according to  claim 5  which further comprises a thermal insulator situated longitudinally between the second temperature sensor and the heating member. 
     
     
         8 . Applicator according to  claim 1 , wherein the application member is removable. 
     
     
         9 . Applicator according to  claim 1 , which 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. 
     
     
         10 . 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 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 (T) representative of the temperature of the heating member,   producing by the unit, on the basis of the first parameter (T), a second parameter (T 1 , T 2 ) representative of the rate of the temperature rise (C 1 , C 2 , C 3 , C 4 ) of the heating member, and   comparing, by the unit, the second parameter (T 1 , T 2 ) to at least one threshold value (Tmax, Tmin)-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.   
     
     
         11 . Applicator according to  claim 2 , wherein:
 the threshold value (Tmin) is a lower threshold, and   the unit is suitable for detecting whether the second parameter (T 1 , T 2 ) is less than or equal to the lower threshold, and, if so, switching off the electrical power supply of the heating member.   
     
     
         12 . Applicator according to  claim 2 , wherein the second parameter (T 1 , T 2 ) 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 is powered by the source of electricity,   a time taken by the first parameter (T) to reach a given value, or   a time constant of the temperature rise (C 1 , C 2 , C 3 , C 4 ) of the heating member, or   combinations thereof, particularly linear combinations thereof.   
     
     
         13 . Applicator according to  claim 3 , wherein the second parameter (T 1 , T 2 ) 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 is powered by the source of electricity,   a time taken by the first parameter (T) to reach a given value, or   a time constant of the temperature rise (C 1 , C 2 , C 3 , C 4 ) of the heating member, or   combinations thereof, particularly linear combinations thereof.   
     
     
         14 . Applicator according to  claim 2 , which 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 (T 1 , T 2 ) being computed by the unit using the first parameter (T) and the third parameter. 
     
     
         15 . Applicator according to  claim 3 , which 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 (T 1 , T 2 ) being computed by the unit using the first parameter (T) and the third parameter. 
     
     
         16 . Applicator according to  claim 4 , which 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 (T 1 , T 2 ) being computed by the unit using the first parameter (T) and the third parameter. 
     
     
         17 . Applicator according to  claim 6  which further comprises a thermal insulator situated longitudinally between the second temperature sensor and the heating member. 
     
     
         18 . Applicator according to  claim 2 , wherein the application member is removable. 
     
     
         19 . Applicator according to  claim 3 , wherein the application member is removable. 
     
     
         20 . Applicator according to  claim 4 , wherein the application member is removable.