Abstract: A dot line printer with a paper feed time controlling capability includes a hammer bank accommodating a plurality of print hammers, a shuttle mechanism for shuttling the hammer bank back and forth along a print line, and a sheet feeding mechanism for feeding a sheet of paper in a direction perpendicular to the direction in which the hammer bank shuttles. When a first predetermined amount of a line space feeding is to be carried out after completion of one line printing, a hammer bank reversing time is prolonged. When more than the first predetermined amount of the line space feeding but less than a second predetermined amount of line space feeding is to be carried out, it is carried out during an extended period of time including both the hammer bank reversing time and the subsequent hammer bank scanning time without prolonging the hammer bank reversing time.

Abstract: In a printer of the type arranged to fire print hammers in accordance with the result of comparison between character codes and print data such that a plurality of subscans are effected during an interval in which a type carrier moves by a distance corresponding to character pitch, a flag bit storing region is provided to a character code memory and/or a print data memory. Data indicative of numerical order of subscans from a print control circuit is added to several lower bits of data used to designate the address of the character code memory, and the resultant sum is compared with the flag bits read out from the flag bit storing region to see whether the addresses of the character code memory are correctly accessed. Another flag bit storing region is provided to a print data memory, and these flag bits are read out and compared with the data indicative of the numerical order of subscans to see if the addresses of the print data memory are correctly accessed.

Abstract: An improved printing magnet drive device for use in a printing apparatus, such as line printer, is disclosed. The improvement comprises a constant voltage control means in which an output terminal voltage of a transistor is compared with a reference voltage and the comparison result is fed back to the transistor so as to control the output terminal voltage of the transistor to a predetermined value, whereby the voltage applied to the printing magnets is substantially maintained unchanged.