Printing apparatus and method

摘要

The present invention provides a printing apparatus and method that can prevent the image grade from lowering. A print head is provided with a plurality of printing elements to print dots on N adjacent rasters and dots on M adjacent columns under different conditions by causing the print heads perform a plurality of (P) main-scanning operations in a main-scanning direction and transporting a printing medium at least once in a sub-scanning direction. A plurality of dot arrangement patterns used for the same level of image data are periodically changed. The plurality of dot arrangement patterns are such that within each period when the patterns are repeatedly used, the number of dots formed in each of said N rasters are equalized, whereas the number of dots formed in each of said M columns are equalized.