US Patent 9516899 Aerosol generating device with improved temperature distribution

There is provided an aerosol generating device configured to receive an aerosol-forming substrate and configured to heat the aerosol-forming substrate using both an internal heater, positioned within the substrate, and an external heater positioned outside of the substrate. The use of both an internal and an external heater allows each heater to operate at a lower temperature than would be required when using either an internal or external heater alone. By operating the external heater at a lower temperature than the internal heater, the substrate can be heated to have a relatively uniform temperature distribution while the external temperature of the device can be kept to an acceptably low level.