Patent ID: 8000884

Claim:
A device for controlling ignition timing of an internal combustion engine, comprising an operation unit, wherein said operation unit calculates knock magnitude related to magnitude of vibration due to knocking, based on magnitude of vibration occurring in said internal combustion engine, said operation unit controls ignition timing of said internal combustion engine, based on a result of comparison between said knock magnitude and a predetermined determination value, said operation unit corrects said determination value, based on an occurrence frequency of said knocking, said operation unit sets a correction amount of said determination value to a value corresponding to a degree of change of the determination value as a result of the determination value being corrected a plurality of times, the degree of change of said determination value being calculated as a difference between a first determination value and a second determination value, the second determination value being temporally different from the first determination value, said operation unit calculates, at a first timing, a first value based on an average of a number of determination values calculated immediately prior to the first timing, said operation unit calculates, at a second timing later than said first timing, a second value based on an average of the number of determination values calculated immediately prior to the second timing, and the degree of change of said determination value is calculated as a difference between said first value and said second value.