PURPOSE: To give a function that can control accumulated heat to a character memory side and to stabilize its density by making character constitution provided with data that corrects the heat history in correspondence to the direction of scanning.

CONSTITUTION: One dot is constituted of a heating section (a) and a recording section (b). In the case where white dots become black dots in (1), remaining heating and recording are performed. When black dots continue in (2), heating is not made and only recording is performed. In this case, the time of energizing in remaining heating information is set according to main scanning time. By this constitution, the density can be stabilized even in high-speed recording.