US Patent 7441539 Multipoint ignition device

Respective heat values of a plurality of electrode pairs P1 to P8 are set individually such that the temperatures of all of the plurality of electrode pairs (P1 to P8) are kept within an appropriate temperature range in which a temperature no lower than a self-cleaning temperature is set as a lower limit temperature and a lower temperature than a pre-ignition temperature is set as an upper limit temperature.