Patent ID: 7465007

Claim:
A printhead for an inkjet printer, the printhead comprising: a series of printhead segments, each segment having an array of nozzles for printing on a print media substrate, the printhead segments positioned relative to each other such that they have a spatial relationship that varies with temperature while maintaining regions of overlap between adjacent printhead segments where part of the printing from one segment overlaps with part of the printing from the adjacent segment such that the extent of the regions of overlap likewise vary with temperature; one or more temperature sensors for measuring the temperature of the printhead segments to determine the extent of the regions of overlap; a printhead controller for providing the printhead segments with print data for printing a continuous tone image and creates a half tone patterns for the nozzles within each of the regions of overlap using a dither matrix with an interpolation function; wherein during use, the printhead controller adjusts the half tone patterns in response to the determined extent of the regions of overlap such that V A +V B is greater than V where V A and V B are the respective independent dither matrix values of a pair of adjacent printhead seaments and V is the continuous tone value to be represented in order to reduce artefacts in the printing on the print media substrate.