To prevent a belt for transferring photoprinting receiving papers from being extended when being sequentially pressed by a plurality of platen rollers, and effectively prevent colors from being shifted by a deflection of feed rollers without increasing costs.

In accordance with the plurality of platen rollers 14-16 being sequentially pressed to thermal heads 10-12, a transfer speed of the photoprinting receiving paper 18 is changed by a preliminarily determined amount. Alternatively, a line period of photoprinting control signals to be applied to the thermal heads 10-12 is changed by a preliminarily determined amount.