AEROSOL GENERATING SYSTEM HAVING MEANS FOR DETERMINING DEPLETION OF A LIQUID SUBSTRATE

• US 20140020693A1
• Filed: 12/22/2011
• Published: 01/23/2014
• Est. Priority Date: 12/24/2010
• Status: Active Grant

• Current Assignee: Philip Morris Products SA (Philip Morris Limited)
• Original Assignee: Philip Morris Products SA (Philip Morris Limited)
• Inventors: Thorens, Michel, Flick, Jean-Marc, Cochand, Olivier, Degoumois, Yvan
• Granted Patent: US 9,814,263 B2
• Time in Patent Office: Days
• US Class Current: 131/273
• CPC Class Codes: A24F 40/10 Devices using liquid inhalable precursors
• CPC Class Codes: A24F 40/53 Monitoring, e.g. fault detection
• CPC Class Codes: A61M 11/041 using heaters
• CPC Class Codes: A61M 11/042 electrical
• CPC Class Codes: A61M 15/008 Electronic counters
• CPC Class Codes: A61M 15/06 Inhaling appliances shaped like cigars, cigarettes or pipes
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/3386 Low level detectors
• CPC Class Codes: A61M 2205/3389 Continuous level detection A61M2205/3393 takes precedence
• CPC Class Codes: A61M 2205/3653 by Joule effect, i.e. electric resistance
• CPC Class Codes: A61M 2205/8206 battery-operated

Abstract

There is provided an electrically operated aerosol generating system for receiving an aerosol-forming substrate. The system includes a liquid storage portion for storing liquid aerosol-forming substrate, an electric heater including at least one heating element for heating the liquid aerosol-forming substrate, and electric circuitry for determining depletion of liquid aerosol-forming substrate heated by the heater based on a relationship between a temperature of the heating element and power applied to the heating element. There is also provided a method in an electrically operated aerosol generating system including a liquid storage portion for storing liquid aerosol-forming substrate and an electric heater including at least one heating element for heating the liquid aerosol-forming substrate, the method including determining depletion of liquid aerosol-forming substrate heated by the heater based on a relationship between a temperature of the heating element and power applied to the heating element.

Claims

1-15. -15. (canceled)

16. An electrically operated aerosol generating system for receiving an aerosol-forming substrate, the system comprising:

a liquid storage portion for storing the liquid aerosol-forming substrate;

an electric heater comprising at least one heating element for heating the liquid aerosol-forming substrate; and

electric circuitry configured to determine depletion of the liquid aerosol-forming substrate based on a relationship between a power applied to the at least one heating element and a resulting temperature change of the at least one heating element.

17. The electrically operated aerosol generating system according to claim 16, wherein the electric circuitry is configured to estimate an amount of liquid aerosol-forming substrate in the liquid storage portion based on the determined depletion.

18. The electrically operated aerosol generating system according to claim 16, further comprising a temperature sensor for measuring the temperature of the at least one heating element, and wherein the electric circuitry is arranged to monitor the temperature of the at least one heating element as sensed by the temperature sensor and determine depletion of liquid aerosol-forming substrate heated by the heater based on the temperature as sensed by the temperature sensor.

19. The electrically operated aerosol generating system according to claim 16, wherein the electric circuitry is arranged to apply a predetermined power to the heating element.

20. The electrically operated aerosol generating system according to claim 16, wherein the electric circuitry is arranged to measure the electrical resistance of the at least one heating element, to ascertain the temperature of the heating element from the measured electrical resistance.

21. The electrically operated aerosol generating system according to claim 20, wherein the electric circuitry is arranged to measure the electrical resistance of the at least one heating element by measuring the current through the at least one heating element and the voltage across the at least one heating element, and determine the electrical resistance of the at least one heating element from the measured current and voltage.

22. The electrically operated aerosol generating system according to claim 18, wherein the electric circuitry is arranged to determine depletion of liquid aerosol-forming substrate heated by the heater by monitoring an increase of the sensed temperature over successive heating cycles as the liquid aerosol-forming substrate in the liquid storage portion is consumed.

23. The electrically operated aerosol generating system according to claim 20, wherein the electric circuitry is arranged to determine depletion of liquid aerosol-forming substrate heated by the heater by monitoring an increase of the ascertained temperature over successive heating cycles as the liquid aerosol-forming substrate in the liquid storage portion is consumed.

24. The electrically operated aerosol generating system according to claim 18, wherein the electric circuitry is arranged to determine depletion of liquid aerosol-forming substrate heated by the heater by monitoring the rate of increase of the sensed temperature over a portion of each heating cycle, over successive heating cycles as the liquid aerosol-forming substrate in the liquid storage portion is consumed.

25. The electrically operated aerosol generating system according to claim 20, wherein the electric circuitry is arranged to determine depletion of liquid aerosol-forming substrate heated by the heater by monitoring the rate of increase of the ascertained temperature over a portion of each heating cycle, over successive heating cycles as the liquid aerosol-forming substrate in the liquid storage portion is consumed.

26. The electrically operated aerosol generating system according to claim 18, wherein the electric circuitry is arranged to determine depletion of liquid aerosol-forming substrate heated by the heater by monitoring an increase in the value of an integral over time of the sensed temperature over a portion of each heating cycle, over successive heating cycles as the liquid aerosol-forming substrate in the liquid storage portion is consumed.

27. The electrically operated aerosol generating system according to claim 20, wherein the electric circuitry is arranged to determine depletion of liquid aerosol-forming substrate heated by the heater by monitoring an increase in the value of an integral over time of the ascertained temperature over a portion of each heating cycle, over successive heating cycles as the liquid aerosol-forming substrate in the liquid storage portion is consumed.

28. The electrically operated aerosol generating system according to claim 16, wherein the electric circuitry is arranged to limit the temperature of the heating element to a maximum temperature, and is arranged to determine depletion of aerosol-forming substrate heated by the heater by monitoring an amount of power applied to the heating element to maintain the maximum temperature.

29. The electrically operated aerosol generating system according to claim 16, further comprising a capillary wick for conveying the liquid aerosol-forming substrate from the liquid storage portion to the electric heater.

30. A method, comprising:

providing an electrically operated aerosol generating system comprising a liquid storage portion for storing a liquid aerosol-forming substrate, and an electric heater comprising at least one heating element for heating the liquid aerosol-forming substrate; and

determining depletion of the liquid aerosol-forming substrate heated by the heater based on a relationship between a power applied to the heating element and a resulting temperature change of the heating element.

31. Electric circuitry for an electrically operated aerosol generating system, the electric circuitry being configured to perform the method of claim 30.

32. A nontransitory computer readable storage medium encoded with a computer program product, which when run on programmable electric circuitry for an electrically operated aerosol generating system, causes the programmable electric circuitry to perform the steps of the method of claim 30.