Patent ID: 7770988

Claim:
A printing apparatus comprising: a plurality of ink cartridges each supplying ink; a print data generating means for generating print data for one or more inks based on input print data; a print data storage means for storing the print data generated by the print data generating means for each of said inks; a print head for discharging ink supplied from each ink cartridge from a nozzle group for each of said inks based on the print data for each ink stored in the print data storage means; and a print data supply means for supplying the print data from the print data storage means to the print head; wherein the print data supply means performs a first switching from supplying a portion of the print data using a first of said inks to the print head to using a second of said inks and performs a second switching from supplying another portion of the print data using the second of said inks to the print head to using the first of said inks so that ink in said plurality of ink cartridges is consumed substantially equally, wherein only one of said first and second switching occurs for each pass of the print head.