US Patent 7448721 Inkjet printing apparatus and inkjet printing method

In an inkjet printing apparatus having a plurality of printing modes with different scanning speeds, first and second preliminary discharge performing positions are provided within the moving area of a carriage as positions where preliminary discharge is performed to cause a printhead to discharge ink irrespective of printing, and a combination of positions where preliminary discharge is performed is set from the first and second preliminary discharge performing positions in accordance with the scanning speed in a set printing mode. This makes it possible to execute preliminary discharge at intervals within necessary intervals even if the scanning speed is decreased when high resolution printing is performed.