Abstract: A method and a device for controlling the motion of a carriage in an ink jet apparatus. First, the printer receives a signal representing a command to replace the cartridge mounted on the carriage. Then, a paper detection device determines whether paper is present in the printing area of the printer. If paper is detected in the printing area, then the carriage is moved outside of the printing area. When no paper is detected by the paper detection sensor, the carriage is moved to the center of the printing area. Then, a user replaces the old ink cartridge with a new ink cartridge and sends a command to the printer indicating that the replacement process is completed. Then the carriage is returned to the position it occupied prior to the printer receiving the replace cartridge command.