Patent ID: 7360856

Claim:
A printing apparatus which uses a printhead having a plurality of printing elements, divides the plurality of printing elements into a plurality of blocks, time-divisionally drives the plurality of printing elements, and prints a halftone image on a printing medium in accordance with a result obtained by performing digital-halftoning for input multi-valued image data in each matrix of a predetermined size, comprising: scanning means for reciprocally scanning the printhead; conveyance means for conveying the printing medium in a direction different from a scanning direction of the printhead; and printing control means for controlling to print a halftone image in each matrix, wherein an arrayed direction of the plurality of printing elements is a conveyance direction of said conveyance means, and said printing control means controls printing of the halftone image by shifting part of image data or shifting driving periods of part of the plurality of printing elements of the printhead in accordance with a relationship between a size of the matrix in the conveyance direction and a size of the block.