Patent ID: 7118191

Claim:
A method of printing an image on a print medium by ejecting ink from a printhead in an ink jet printer, the printhead having a column of N nozzles on a printhead, where N is an integer greater than eight, for selectively ejecting ink drops onto a printing area of the print medium at a plurality of ink drop locations arranged in a grid, the print medium being movable in an advance direction, the method comprising: performing a series of at least three scanning passes of the printhead across the print medium, with the print medium being advanced between scanning passes, wherein each scanning pass comprises: moving the column of nozzles horizontally across the printing area in a plurality of raster lines for selectively addressing ink drop locations according to an addressing pattern for that pass, wherein each ink drop location is addressed in one of the series of scanning passes, and ejecting ink from a nozzle at an ink drop location during a particular scanning pass according to a corresponding desired image data bit and a corresponding bit of the addressing pattern for that scanning pass, using a first scanning pass having a first addressing pattern for a first contiguous portion of the raster lines addressed by the first scanning pass and a second addressing pattern for a second contiguous portion of the raster lines addressed by the first scanning pass, wherein the second portion of the raster lines addressed by the first scanning pass corresponds to a lower region of the first scanning pass, and the first addressing pattern of the first pass has an interlacing percentage that is greater than an interlacing percentage of the second addressing pattern of the first pass; using a second scanning pass having at least a first addressing pattern used for a first contiguous portion of the raster lines addressed by the second scanning pass; and, using the at least third scanning pass having a first addressing pattern for a first contiguous portion of the raster lines addressed by the at least third scanning pass and a second addressing pattern for a second contiguous portion of raster lines addressed by the at least third scanning pass, wherein the first portion of the raster lines addressed by the at least third scanning pass corresponds to an upper region of the at least third scanning pass, and the first addressing pattern of the at least third pass has an interlacing percentage that is less than an interlacing percentage of the second addressing pattern of the at least third pass, and further wherein the at least third scanning pass together with the prior scanning passes have addressed each ink drop location in the plurality of raster lines addressed by the first scanning pass, and the first scanning pass and the at least third scanning pass define an overlapping boundary region of raster lines.