Ink jet printing apparatus and ink jet printing method

An ink jet printing method which forms an image on a print medium by moving a print head having an array 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 method comprising:

• a nozzle information generation step for generating nozzle information representing an ejection characteristic of each nozzle according to a landing state on the print medium of the ink droplet ejected from each nozzle;
• an estimation step for estimating, based on the nozzle information generated by the nozzle information generation step and the print data, an effect that the ink droplet ejected from each nozzle has on the image to be formed;
• a correction information generation step for generating correction information to correct an ink ejection condition of each nozzle according to a result of estimation by the estimation step;
• and
• a control step for controlling a driving of the nozzles according to the print data and the correction information.

An ink jet printing apparatus which forms an image on a print medium by moving a print head having an array 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:

• a grayscale correction means for performing an ink dot grayscale correction according to density difference data representing a density difference between an actual density of an ink dot formed on the print medium and an ideal density of the dot;
• a deviation correction means for performing a dot deviation correction based on deviation data representing an amount of deviation, or a difference, between an actual landing position of an ink dot formed on the print medium by the ink droplet ejected from each nozzle and an ideal landing position of the ink dot;
• and
• a control means for controlling the grayscale correction means and the deviation correction means according to at least the density difference and the amount of deviation.

An ink jet printing method which forms an image on a print medium by moving a print head having an array 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 method comprising:

• a grayscale correction step for performing an ink dot grayscale correction according to density difference data representing a density difference between an actual density of an ink dot formed on the print medium and an ideal density of the dot;
• a deviation correction step for performing a dot deviation correction based on deviation data representing an amount of deviation, or a difference, between an actual landing position of an ink dot formed on the print medium by the ink droplet ejected from each nozzle and an ideal landing position of the ink dot;
• and
• a control step for controlling the grayscale correction means and the deviation correction means according to at least the density difference and the amount of deviation.