To prevent a stepping motor from becoming out of step by a method wherein the number of excitations for driving the stepping motor is made larger than the number of excitations corresponding to the minimum stroke necessary for the predetermined amount of the action of a shuttle.
By driving a pulley 16 through a stepping motor 20 by means of a shuttle driving circuit 50, a hammer bank 10 and a counter-balancer 14 are reciprocated to the direction of a crossbeam in phases opposite to each other. During this reciprocating motions of the hammer bank and of the counter- balancer, by means of a printing controlling device 30 through a shuttle controlling circuit 40, printing hammers are controlled so as to execute a printing through an ink ribbon 100 onto the predetermined position of a printing paper 200. In a dot line printer as mentioned above, the number of excitations for driving the stepping motor 20 is set to be larger than the number of excitations corresponding to the minimum stroke necessary for the predetermined amount of the action of a shuttle. As a result, the over-running of a rotor is absorbed by the inertia forces of the hammer bank 10 and of the counter-balancer, resulting in preventing the out of step of the stepping motor 20 from developing.
NAKAHARA SHINGO
NAMEKAWA MASAKAZU
HIRATSUKA MASABUMI
