Abstract: A carriage motor controller for a printer. The controller includes a drive mechanism for driving a carriage motor to thereby cause a carriage to travel; a detector for detecting a position and a speed of the carriage while the carriage is travelling; a measuring device for measuring characteristics of the carriage motor on the basis of the detected position and speed; storage for storing the measured characteristics; a first controller for controlling the drive mechanism and causing the carriage to travel for the purposed of taking the necessary measurements, the measurements being taken after a power switch has been turned on, after a sheet has been fed, or after a predetermined time has elapsed; and a second controller for controlling the drive mechanism upon reception of a print command on the basis of the print command and the stored characteristics to thereby cause the carriage to travel for printing.

Abstract: A printer controlling system which can perform printing at predetermined printing density even when the carriage is being accelerated or decelerated is disclosed. When the carriage is traveling, position pulses are generated at constant travel distance intervals. The carriage travel speed is measured on the basis of the time intervals during which the position pulses are generated. Further, the time at which the carriage reaches each predetermined printing position is estimated on the basis of the measured travel speed, and the actual printing is made when the current time matches the estimated arrival time.