A timing signal generator generates an ejection timing signal each time a printing paper travels a predetermined distance relative to a head, and a driving signal generator inputs a driving signal based on writing data to the head each time an ejection timing signal is generated. In the course of printing, when an interval between two continuous ejection timing signals is equal to or longer than twice a basic time period of input of driving signal which is fixed for a head, a non-ejection driving signal which is a driving signal indicating a non-ejecting operation is input to the head between two driving signals respectively associated the two continuous ejection timing signals. Accordingly, it is possible to reliably and properly perform ejection of ink based on writing data with a time period equal to or longer than the basic time period.