A spring is bridged between a pair of press levers, and a pair of driven rollers is pressurized uniformly, so that clamping and conveying force of the sheet of paper P on the front side and rear side by conveying rollers and the driven rollers is made equal such as Pf=Pr, the sheet of paper P are prevented from being skewed, while the sheet of paper P are clamped and conveyed by a conveying device, and the good conveying of the sheet of paper P is improved, thus the image quality is improved.