Patent ID: 7201462

Claim:
An ink jet printing apparatus which forms an image on a print medium by moving a print head having an away of nozzles and the print medium relative to each other and at the same time ejecting ink droplets from the nozzles according to print data of the image to be printed, the ink jet printing apparatus comprising: nozzle information generation means for generating nozzle information representing an ejection characteristic of each nozzle according to a result of measuring a landing state of each of dots formed by the ink droplets which are ejected from the nozzles of the print head onto the print medium by measuring the landing state coffesponding to each of the nozzles; estimation means for estimating, for each nozzle of the plurality of nozzles based on the nozzle information, a degree of influence which affects the density of an image at a position of a dot to be formed by an ink droplet ejected from the nozzle, the degree of influence being affected by both the nozzle corresponding to the position of the dot to be formed and another nozzle in the neighborhood of the nozzle; correction information generation means for generating correction information to correct an ink ejection condition of each nozzle according to a result of estimation by the estimation means; and control means for controlling a driving of the nozzles according to the print data and the correction information, wherein the nozzle information generation means generates information which represents nozzle ejection characteristics according to a result of measuring an amount of deviation between an ideal landing position of the ink droplet ejected from each of the nozzles of the print head onto the print medium and an actual landing position of the ink droplet ejected from each of the nozzles of the print head onto the print medium, and wherein the estimation means obtains the degree of influence which affects the density of the image at the position of the dot by obtaining a dot area, present within a target area, of the dot formed by an ink droplet ejected from a nozzle corresponding to a predetermined position of the dot and a dot area, present within the target area, of the dot formed by an ink droplet ejected from the other nozzle, based on an amount of deviation corresponding to each of the plurality of nozzles.