Patent Number: 6,166,828

Title: Clearing ink jet nozzles during printing

Abstract: In an ink jet printer having plural ink ejection nozzles on a print head, additional firings are added for each print element so as to ensure that the ink jet nozzles remain unclogged during printing. The extra firings are effected directly onto the recording medium in a controlled way so as to ensure that printout quality is not adversely affected. Particularly, extra firings of lighter-colored inks are effected over regions of darker colored ink, and any color shift caused thereby is compensated by changing printout data in the surrounding region.

Inventors: Yamada; Akitoshi (Irvine, CA), Hirabayashi; Hiromitsu (Irvine, CA)

Assignee: Canon Kabushiki Kaisha

International Classification: B41J 2/165 (20060101); G06K 15/02 (20060101); G06K 15/10 (20060101); H04N 1/52 (20060101); B41B 015/00 (); B41J 015/00 (); B41J 002/205 (); B41J 002/165 ()

Expiration Date: 12/26/2017