摘要 |
PURPOSE:To uniformize a printing density even in a continuous printing of the same image or in a high-speed printing. CONSTITUTION:Based on an internal temp. T1 of a thermal head 8, a candidate for conduction time pattern is selected. Based on an temp. difference DELTAT between the internal temp. T1 of the thermal head 8 and an ambient temp. T2, the candidate for conduction time pattern is corrected. In the corrected conduction time pattern, a conduction time(t) to the thermal head 8 in accordance with a gradation number(n) is determined. In addition, based on both the internal temp. T1 and the temperature difference DELTAT, the ON/OFF operation and rotating speed of a cooling fan 22 are controlled. |