Patent ID: 6331038
Filing Date: 2001-12-18
Classification: B41J

Abstract:
A method of sensing directional aberrations among ink-jet printhead nozzles on the same printhead, comprising:mounting the printhead on a scanning carriage;selecting one group of nozzles on said printhead and printing from said one group of nozzles a first repeating pattern of blocks on a print medium as the carriage is scanned along a scan axis;advancing the print medium relative to the carriage along a media axis by an incremental distance relative to a swath height;printing from said one group of nozzles a second repeating pattern on the print medium as the carriage is scanned along the scan axis, the second pattern including second pattern blocks interleaved between the first pattern blocks;optically sensing the relative positions of the first and second patterns to record measurements for determining at least one directional deviation characteristic of the printhead.