PURPOSE: To make it possible to always perform high quality recording by making it possible to prevent the recording of ink to a head roller by controlling the heat generating range of a heat generator on the basis of the width of recording paper, by detecting the width of the recording paper and controlling the heat generator corresponding to the detected result.

CONSTITUTION: The heat generator of a thermal head 5 is 8PEL/mm (PEL=printing element) (one dot) and, for example, when heat generation is possible to an A4 size, the number of the heat generators are 8×126mm=1728PEL. A recording data control part 48 takes out recording data (dot pattern) having the number of dots corresponding to a paper size from external machinery 50 in accordance with the transmission clock signal VCLK thereof and outputs the same to a head driving circuit 46. Therefore, the heat generator of the thermal head 5 is allowed to generate heat in accordance with the supplied dot pattern and the clock signal VCLK supplied from an I/O port 45. The number of the heat generators generating heat at this tims are 1,184 dots corresponding to the size of transfer paper P.