Abstract: A printing mode setting portion outputs energizing time data corresponding to a selected printing mode when selecting the printing mode according to operation of the operation unit. Based on the energizing time data, the energizing time period of a head energizing signal which is output from a head driving portion to a driving coil of a dot printer head is controlled by the energizing time control portion 6. When printing mode having a high dot density is selected, printing energy is reduced and the energizing time period is refined for the driving coil 8, thus making it made possible to lower the noise level.

Abstract: Disclosed is a method for driving a printer carrier. One power source is connected via a constant current circuit to the carrier motor. Data storing means stores the current command data corresponding to the acceleration, constant speed printing and deceleration of the carrier motor. According to the method, the current command data from the data storing means is latched in synchronism with a clock signal. The latched data is converted to a current reference voltage. The output current of the constant current drive circuit is varied in accordance with the current reference voltage. Changing the current command data as desired makes it possible to adjust freely the torque of the carrier motor for acceleration and deceleration on a constant voltage from one power source.