Aerosol-Generating Device and Method of Indicating an Operational State of an Aerosol-Generating Device

Abstract

An aerosol-generating device has thermochromic material visible from outside the device and extending in a longitudinal direction and a heat transfer structure inside the device relative to the thermochromic material and essentially extending in the same longitudinal direction as the thermochromic material and at least overlapping with it, wherein a thermal resistance of the heat transfer structure increases in the longitudinal direction. Further, a method of indicating at least one operational state of an aerosol-generating device by changing colour of thermochromic material visible from outside is presented, wherein at least two portions of thermochromic material are heated successively due to a thermal resistance of a heat transfer structure inside the device relative to the thermochromic material increasing in a longitudinal direction of the thermochromic material and the heat transfer structure.

1 . An aerosol generating device having:
 thermochromic material visible from outside the device and extending in a longitudinal direction,   a heat transfer structure inside the device relative to the thermochromic material and extending in substantially the same longitudinal direction as the thermochromic material and at least overlapping with it the thermochromic material,   wherein a thermal resistance of the heat transfer structure increases in the longitudinal direction.   
     
     
         2 . The aerosol generating device of  claim 1 , wherein the thermal resistance is highest at a mouthpiece end of the device. 
     
     
         3 . The aerosol generating device of  claim 1 , wherein the thermochromic material is filled in at least one recess formed on a surface of the device. 
     
     
         4 . The aerosol generating device of  claim 1 , wherein the thermochromic material is a Leuco dyes-based paint. 
     
     
         5 . The aerosol generating device of  claim 1 , wherein the heat transfer structure inside the device relative to the thermochromic material is adapted to reduce a temperature by at least 75%. 
     
     
         6 . The aerosol generating device of  claim 1 , wherein the heat transfer structure inside the device relative to the thermochromic material is shorter than an oven of the device in a longitudinal direction of the device. 
     
     
         7 . The aerosol generating device of  claim 6 , wherein the heat transfer structure fully overlaps with the oven in the longitudinal direction. 
     
     
         8 . The aerosol generating device of  claim 1 , wherein the heat transfer structure inside the device relative to the thermochromic material is adapted to be heated by an electrical resistance. 
     
     
         9 . The aerosol generating device of  claim 1 , wherein the thermochromic material is provided on at least one portion of a surface of the device. 
     
     
         10 . The aerosol generating device of  claim 1 , wherein the heat transfer structure is composed of at least two different materials, the content of which changes along the longitudinal direction. 
     
     
         11 . The aerosol generating device of  claim 10 , wherein the at least two different materials are provided with at least one step. 
     
     
         12 . The aerosol generating device of  claim 10 , wherein the at least two different materials are provided with at least two projections having different thicknesses measured in the longitudinal direction. 
     
     
         13 . A method of indicating at least one operational state of an aerosol generating device by changing a colour of thermochromic material visible from outside the device, wherein at least two portions of thermochromic material are heated successively due to a thermal resistance of a heat transfer structure inside the device relative to the thermochromic material increasing in a longitudinal direction of the thermochromic material and the heat transfer structure. 
     
     
         14 . The method of  claim 13 , wherein heat is transferred to the thermochromic material from an oven and/or an electrical resistance. 
     
     
         15 . The method of  claim 14 , wherein the oven and/or the electrical resistance is controlled by a controller. 
     
     
         16 . The aerosol generating device of  claim 1 , wherein the heat transfer structure inside the device relative to the thermochromic material is adapted to reduce a temperature by a maximum of 90%.