There is provided a printhead for an ink jet printer, including a primary
and a secondary array of nozzles in the printhead, the nozzles in the
primary array of nozzles being in alignment with the nozzles in the
secondary array of nozzles in a printing process direction; detection
system for detecting defective nozzles in both the primary array of
nozzles and in the secondary array of nozzles; a first mode operation
having means for selectively activating nozzles in the secondary array of
nozzles that are in alignment with defective nozzles in the primary array
of nozzles; and a second mode of operation having means, responsive to
the detecting means, for translating the secondary array of nozzles in
relation to the primary array of nozzles along a path to a first position
to realigned the nozzles in the primary array of nozzles to nozzles in
the secondary array of nozzles if defective nozzles are aligned in both
the primary and the secondary array of nozzles.