Patent ID: 7815274
Filing Date: 2010-10-19
Classification: B41J

Abstract:
1. A method for visually detecting misdirecting nozzles of an inkjet printer, the method being suitable for detecting nozzles misdirecting in a first direction, the inkjet printer comprising a print head, the print head comprising at least one array of at least two nozzles, each nozzle being configured to eject an ink drop for generating a dot on a recording medium, the method comprising printing a test pattern, and for each of the at least one array, printing the test pattern comprises the steps of: selecting a nozzle of said at least one array to be investigated; identifying for said selected nozzle a number of compensating nozzles, each compensating nozzle being suitable to replace said selected nozzle for printing a dot; printing a row, the row extending in a second direction being different from the first direction and comprising at least two dot groups, each dot group comprising at least one dot, wherein at least one dot group is printed by said selected nozzle and at least one other dot group is printed by a compensating nozzle selected from said number of compensating nozzles identified in said step of identifying; visually comparing a position of a dot group in the row printed by said selected nozzle with a position of a dot group in the row printed by said compensating nozzle selected in said step of printing; and investigating a plurality of the at least two nozzles of said array by repeating said steps of selecting, identifying and printing, wherein the dot groups printed by the compensating nozzles are lying on a diagonal of a two-dimensional array of dot groups.