Patent ID: 6554390
Filing Date: 2003-04-29
Classification: B41J

Abstract:
A method for aligning ink-jet pens in a hard copy apparatus having a scanning carriage with a plurality of said ink-jet pens mounted therein, each of said pens having a printhead, each of said printheads having a plurality of ink drop firing nozzles, said pens being controlled by a printhead ink-jet nozzle-firing algorithm, said method comprising:printing a test pattern on a single sheet of print media, said test pattern including repetitious pairs of colored test objects wherein said pairs of colored test objects are respectively related to a plurality of error correction values for aligning said printheads such that in combination said values are defined for said algorithm; optically measuring actual offsets between the objects of each pair wherein offsets are indicative of respective printhead alignment aspects, including x-axis, y-axis, and z-axis alignments; calculating at least one printhead alignment error correction factor from said actual offsets; and providing a printhead alignment error correction factor to said nozzle-firing algorithm.