Print head motor control system for printer with moving print head.

摘要

The present invention relates to a printer of the type which comprises a print head (24) for performing printing operations on a print medium, a drive system for moving the print head across a print medium at a selected speed, and a print head control system. The control system includes generating means for generating print head movement signals (ENC A, ENC B) corresponding to print head movement, a processor (2, 10), responsive to the print head movement signals and a command signal representing a required print head movement speed, to generate a drive signal (PWM) for supplying to the drive system so as cause movement of the print head at the required speed.
<??>According to the invention the printer is characterised in that the processor comprises means (2) for repeatedly comparing the print head movement signals with the command signals at predetermined time intervals and for changing the drive signal by an equal amount, for each comparison operation that indicates that the print head movement speed differs from the command signal speed, until the print head attains the required speed.
<??>The present invention also relates to a method of controlling the movement of the print head of a printer utilising a print head control system as above.