Method for controlling nozzle firing in overlapped printhead segments
View Patent ↗A method of controlling the firing of nozzles within overlapped segments of a printhead is provided, in which temperatures of adjacent segments are measured to determine an overlapped region of the adjacent segments and a half toning firing pattern of a continuous tone image for coextensive nozzles of the adjacent segments within the determined overlapped region is adjusted such that V A +V B is greater than V, where V A and V B are respective independent dither matrix values of the adjacent segments and V is a continuous tone value to be represented.
1. A method of controlling the firing of nozzles within overlapped segments of a printhead, the method comprising the steps of:
measuring temperatures of adjacent segments to determine an overlapped region of the adjacent segments; and
adjusting a half toning firing pattern of a continuous tone image for coextensive nozzles of the adjacent segments within the determined overlapped region such that V A +V B is greater than V, where V A and V B are respective independent dither matrix values of the adjacent segments and V is a continuous tone value to be represented.
2. A method as claimed in claim 1 wherein, in the adjusting step, the firing pattern is adjusted so that the coextensive nozzles of the adjacent segments never both fire at the same time.
3. A method as claimed in claim 1 , wherein, in the adjusting step, the firing pattern is adjusted so that the coextensive nozzles of the adjacent segments never both produce an output.
4. A method as claimed in claim 1 , further including the step of assigning an output dot to one coextensive nozzle stochastically according to a probability given by a current interpolation factor of an interpolation function used to create the half toning firing pattern.
5. A method as claimed in claim 1 wherein the half toning firing pattern is created using a dither matrix with an interpolation function.
6. A method as claimed in claim 5 wherein, in the adjusting step, the output from the dither matrix and an overlap signal derived from the determined overlapped region are summed.
7. A method as claimed in claim 6 wherein, in the adjusting step, the summed output and signal are compared to continuous tone data to determine half tone data for the coextensive nozzles of the adjacent segments.
8. A method as claimed in claim 6 wherein the summed output and signal are subtracted from the continuous tone data to determine the half tone data.