Patent ID: 7554691

Claim:
A printing device that prints an image on a printing medium, said printing device comprising: a raster formation assembly that is scanned in a raster-forming direction relative to the printing medium and completes each raster or each dot line on the printing medium by a preset number of multiple scans; a shift module that shifts the raster formation assembly in a perpendicular direction orthogonal to the raster-forming direction relative to the printing medium after every scan of the raster formation assembly in the raster-forming direction for raster formation; an image data receiving module that receives object image data representing an object image to be printed; a dot on-off state determination module that determines dot on-off state with regard to a number of pixels constituting the object image, based on the received image data; a determination result storage module that classifies determination results representing dot on-off state of plural pixels on each raster into multiple groups according to allocation of the preset number of multiple scans to raster formation in the plural pixels on the raster and stores the determination results classified in the multiple groups; and a determination result supply module that reads the determination results of each classified group from the classified storage of said determination result storage module synchronously with each scan of the raster formation assembly in the raster-forming direction, and supplies the read determination results of each classified group to the raster formation assembly, which then creates dots in dot-on pixels to complete each raster on the printing medium according to the supplied determination results of each classified group.