Color thermal printer having tension roller

Abstract

A color thermal printer has a feed roller set, a thermal head, and a tension roller set that are serially arranged along a transporting path. The feed roller set and the tension roller set are rotated by respectively a stepping motor and a DC motor. The stepping motor rotates forwards. Simultaneously, the DC motor rotates the tension roller set forwards, to apply a first transporting force to the continuous recording sheet at a level higher than a predetermined transporting force of the feed roller set. Also, the stepping motor rotates backwards. Simultaneously, the DC motor rotates the tension roller set backwards, to apply a second transporting force to the continuous recording sheet at a level lower than the predetermined transporting force. A torque limiter applies load to the tension roller set relative to an output shaft of the DC motor, to keep the tension roller set rotated at a speed according to the predetermined transporting force simultaneously with application of the first or second transporting force to the continuous recording sheet. Thus, transport of the continuous recording sheet is stabilized according to a difference between the predetermined transporting force and the first or second transporting force.