Patent ID: 7201460

Claim:
In an ink ejection print head comprising a plurality of overlapping print head segments, wherein the spatial relationship between adjacent segments is variable with time, a method for controlling the firing of nozzles within the overlapped segments comprising the steps of: (a) determining a measure of the overlap between a first print head segment adjacent to a second print head segment, by measuring a temperature of the first print head segment and a temperature of the second print head segment to determine a relative displacement of the first print head segment and the second print head segment; (b) creating a half toning pattern for the nozzles in the region of overlap of the first print head segment and the second print head segment using a dither matrix with an interpolation function, such that at least one nozzle to be fired from the first print head segment and at least one nozzle to be fired from the second print head segment are coextensive in the region of overlap between the first print head segment and the second print head segment; and (c) adjusting said half toning pattern as a function of said measure in the overlap between the first print head segment and the second print head segment to reduce artifacts produced by the overlapping of the first print head segment and the second print head segment, such that V A +V B is greater than V where V A and V B are respective independent dither matrix values of the two adjacent segments and V is a continuous tone value to be represented.