Abstract: A printing control system includes a recording head having a plurality of heating resistor elements and a head driver for driving the recording head and calculates printing data to be sent to the head driver according to logical calculations using printing data one and two steps ahead of the current step. A printing time of the data is divided into a plurality of time intervals. The logical operations are performed according to different algorithms every time interval. The printing data of the respective time intervals are printed. By combining the data printed during the previous time intervals, the density of the current printing data is determined.