Abstract: The timing signal generated by the paper sending-out roller or the paper detector outputs a signal with synchronously the paper sending-out cycle. The flash lamp photoflashes with synchronously the output signal. The photoflash is generated in accordance with length of carrying direction of the paper. The paper sending-out roller sends out one of a plurality of the papers in accordance with a predetermined timing signal, and the flash lamp photoflashes at a predetermined number of times and stops the flashlight at a predetermined time in accordance with the predetermined timing signal as an index. The paper detector is installed at a position close to the paper carrying apparatus line from the flash fusing apparatus, and a delay circuit is provided so as to delay the detection output of the paper detector with a predetermined time. No photoflash irradiates the gap between a precede paper and a next paper at the continue printing the a plurality of cut sheets.