Patent ID: 6450608
Filing Date: 2002-09-17
Classification: B41J

Abstract:
A method of printing with a set of scanning ink-jet printheads, the method comprising:receiving a first set of data indicative of a printed image to be rendered; parsing the data into swaths subsets; determining printhead nozzle firing requirements for a next swath to be printed; prior to printing the next swath on a sheet of print media, firing nozzles determined as required for the next swath at a drop detection target located within a print zone of the printheads and having a matrix of detecting elements sized as a function of size of pixels to be printed wherein the elements are arranged in a like plane and in like orientation as the pixels to be printed and located adjacently to the sheet of print media in the print zone; based upon electrostatic detecting elements struck by a single drop from each of said nozzles determined as required, determining if any of the nozzles is malfunctioning and if any of the nozzles has a firing trajectory error; and correcting for any detected malfunctioning nozzles and any firing trajectory errors prior to printing the next swath.