Patent ID: 7119821

Claim:
A color thermal printer for recording full color image by recording one color image at each of printing units during transportation of a long recording sheet by a couple of transporting rollers, a plurality of said printing units being disposed along the transporting path, each of said printing units including a platen roller for supporting said long recording sheet, and a thermal head for executing thermal recording of each color image by pressing said recording sheet which is supported by said platen roller, said color thermal printer comprising: a rotating speed detector disposed on at least one said platen roller for detecting rotating speed of the at least one said platen roller; and a controller for recording image by driving said thermal head of each printing unit when transporting quantity of said recording sheet transported by said transporting roller couple reaches target value corresponding to the recording start position, the controller calculating the transporting correction quantity of said recording sheet from the rotating speed fluctuation amount of the at least one said platen roller, to correct said target value so as to correspond to the recording start position of a directly downstream printing unit.