PURPOSE: To prevent the occurrence of unevenness in split recording boundary by controlling a speed-indicating means for a motor driving a carriage.

CONSTITUTION: A carriage 8 on which plural ink jet heads 11W14 are mounted is reciprocally moved on a recording paper 5 through a wire 10 and a pulley 12 by means of a motor 11 driven by a motor driving circuit 13. On the other hand, pulse oscillators 141W145 whose oscillating frequencies are increased little by little by as much as a given value are connected to the input side of OR gate, and timing pulse from its output side is put in the motor-driving circuit 13. In such a recorder, by a signal corresponding to the smoothness of a paper, obtained by a photosensor 18 provided on the recording paper 5, proper ones of relay contacts 151cW155c are closed and corresponding pulse oscillator (one of 141W145) is operated; that is, the frequency of timing pulse is decreased when smoothness is low or it is increased when the smoothness is high.