Patent ID: 7866779

Claim:
A printing system comprising a controller and a memory unit, wherein the controller is configured to execute a routine stored in the memory unit to control a printhead having a first set of nozzles and a second set of nozzles, wherein controlling the printhead comprises: causing the printhead to print with the first set of nozzles and not with the second set of nozzles, when printing at a first horizontal resolution, and causing the printhead to print with both the first set of nozzles and the second set of nozzles when printing at a second horizontal resolution, the second horizontal resolution being greater than the first horizontal resolution; and replacing a defective nozzle in the first set of nozzles by, when printing is performed with just the first nozzles at the first resolution, not using the second set of nozzles for printing except for a plurality of nozzles in the second set of nozzles that are located in a horizontal position close to a horizontal position of the defective nozzle, the plurality of nozzles in the second set of nozzles being used to replace output from the defective nozzle.