Inkjet printing apparatus and carriage control method for controlling carriage speed

A printing apparatus which prints on a printing medium by discharging ink from an inkjet printhead while reciprocating, along a guide rail which guides and supports a carriage, the carriage to which the inkjet printhead is mounted, comprising:

• a carriage motor configured to supply a driving force for moving the carriage;
• a detection unit configured to detect a position of the carriage in a direction of the reciprocation;
• a calculation unit configured to calculate a carriage speed based on a position detection signal output from said detection unit;
• a feedback control unit configured to control drive of said carriage motor by feeding back the position detection signal obtained from the position of the carriage that has been detected by said detection unit and a speed signal indicating the carriage speed calculated by said calculation unit;
• a compensation unit configured to compensate for a loss due to friction generated between the carriage and the guide rail with respect to a motor instruction value used to control the drive of said carriage motor by said feedback control unit;
• and
• an identification unit configured to identify, based on the speed signal, whether the friction is static friction or kinetic friction, and determine a compensation value of said compensation unit in accordance with the identification,
• wherein said identification unit determines the compensation value of said compensation unit based on a speed signal of the carriage that has been obtained by preliminarily driving the carriage and a motor instruction value.

A carriage control method for a printing apparatus which prints on a printing medium by a printhead while reciprocating, by a driving force supplied from a carriage motor along a guide rail which guides and supports a carriage, the carriage to which the printhead is mounted, comprising:

• detecting a position of the carriage in a direction of the reciprocation;
• obtaining a moving speed of the carriage;
• controlling drive of the carriage motor by feeding back at least one of the detected position and the moving speed of the carriage;
• compensating for a loss due to friction generated between the carriage and the guide rail with respect to a motor instruction value used to feedback-control the drive of the carriage motor;
• and
• identifying, based on the moving speed, whether the friction is static friction or kinetic friction, to determine a compensation value for the compensation in accordance with the identification,
• wherein a motor instruction value corresponding to the static friction is used as the compensation value when the moving speed is in the vicinity of “0”, and a motor instruction value corresponding to the kinetic friction is used when the moving speed is higher than the vicinity of “0”.