Patent ID: 7484831

Claim:
A printhead module having a plurality of rows of nozzles configured to extend, in use, across at least part of a printable pagewidth, each row including an offset row portion disposed at only one end of the printhead module, the nozzles in each row being logically grouped into at least first and second fire groups, the nozzles of each offset row portion being misaligned with respect to the other nozzles of that row, the printhead module being configured to sequentially fire, for each row, the nozzles of each fire group, such that each nozzle in the sequence from each fire group is fired simultaneously with respective corresponding nozzles in the sequence in the other fire groups, wherein: the rows are disposed in pairs extending generally transverse to a direction media is to be moved relative to the printhead module, the rows in each pair of rows being configured to print the same color ink as each other; the nozzles are fired row by row such that, for a first print line, the nozzles of one row of each pair of rows are fired, and for a sequential second print line, the nozzles of the other row of each pair of rows are fired; and the offset row portions of at least some of the rows are different in length than the offset row portions of at least some of the other rows.