PURPOSE: To make it possible to compensate an irregularity in printed position at a recording head driven by a pulse motor, by deciding a current value for an excitation phase of the pulse motor according to the determination of a pulse-motor excitation state.

CONSTITUTION: While a current is carried from I1 to I2, transistors(Tr) Q1 and Q4 are turned on, and transistors Q2 and Q3 are turned on while a current is carried from I2 to I1. A previous excited state of each PM phase is determined after initialization of power-on state. Consequently, a present excited state of each phase is detected to determine whether one-phase excitation or two- phase excitation. In the case of one-phase excitation, the circuit generates one as an output at a terminal Is, while zero is generated as an output in the case of two-phase excitation, because the current value becomes 1/√2. By these operations, an irregularity in torque of the pulse motor, namely an irregularity in movement, can be eliminated, and thereby an irregularity in printing position can be reduced.