Patent ID: 6857716

Claim:
A method for controlling a printer that has a printing head for printing data, the method comprising the steps of: examining a relationship of a position, in each printing pass, of each of a plurality of pins provided in a vertical direction of the printing head to a plurality of raster lines to be printed in a predetermined printing range, based on a vertical resolution of the print data, when a unit of vertical transfer of the printing head is not a reciprocal of an integral vertical resolution of the print data, and a pitch of the pins of the printing head is not any one of an integral multiple of the vertical resolution and the reciprocal of the integral vertical resolution; preparing a raster-line/pin-relationship table in which pins to be actuated for printing the raster lines to be printed are determined in each printing pass based on the relationship between the position of the pins and the raster lines; determining a number of printing passes and a position of a print-starting raster line; consulting the raster-line/pin-relationship table according to the determination; and printing the predetermined printing range by actuating the pins in each printing pass based on the raster-line/pin-relationship table, the pitch of the pins of the printing head, the amount of the unit of vertical transfer of the printing head, the position of the print-starting raster line, and a number of passes in the horizontal direction required for printing the predetermined printing range.