JPS6440345A - Wire dot printer - Google Patents

Abstract

PURPOSE:To enable change of printing density by allowing a printing head with each group of a plurality of printing wires, in a single row, connected to an electromagnetic drive mechanism and a plurality of groups of printing wires arranged sequentially at a shifted position with an equal space interposed in a subscan direction to control a printing signal selectively using every other group of printing wires. CONSTITUTION:For instance, when a printing signal of 48 dots is input from an external device 48, a control circuit causes dots of the 1+Nth line of a dot signal in a single row to be printed by the first row printing wire 191 by 1/4 of the dot data of said line, at a rate of every other four dots of a single line of a dot pattern data. Next, at the time when a printing head moves at every l interval of arrangement, dots of the 2+4Nth, 3+4Nth and 4+4Nth lines of a single row of dot data printed previously are printed by means of printing wires 192, 193, 194. Thus printing of the first line dots is completed. After this, printing of the second line dots is executed. When a printing signal of 24 dots is input from the external device, dots of the second and fourth lines are rendered inoperative, which results in printing at a dot density half as much as that when all printing wires are operative. Consequently, requirements for two kinds of printing densities, low and high, can easily be satisfied.