Patent ID: 7758143

Claim:
A printhead module for use in a printhead having a plurality of printhead modules, the print head module comprising: a first row of contiguous and evenly spaced nozzles for ejecting ink of a first type or colour, the first row of nozzles extending in a direction transverse to a feed direction of print media past the printhead; and a second row of contiguous and evenly spaced nozzles for ejecting ink of a second type or colour different to the first type or colour, the second row of nozzles extending in the direction transverse to the feed direction of print media past the printhead, wherein each of the rows of nozzles includes an odd sub-row and an even sub-row, the nozzles in the odd sub-row being spatially offset with respect to the nozzles in the even sub-row in the direction transverse to the feed direction of print media past the printhead, the odd sub-row of nozzles includes a vertical alignment discontinuity, and the nozzles in the odd sub-row on one side of the vertical alignment discontinuity are displaced relative to nozzles in the same odd sub-row on an opposite side of the vertical alignment discontinuity in a direction of intended print media travel relative to the printhead, and the even sub-row of nozzles includes a vertical alignment discontinuity, and the nozzles in the even sub-row on one side of the vertical alignment discontinuity are displaced relative to nozzles in the same even sub-row on an opposite side of the vertical alignment discontinuity in a direction of intended print media travel relative to the printhead, wherein either the odd or even sub-row of nozzles of a row of nozzles on one side of the vertical alignment discontinuity is respectively overlapped with the even or odd sub-row of nozzles of the row of nozzles on the opposite side of the vertical alignment discontinuity in the travel direction of print media.