Inkjet printer, printing method, method for producing print deliverable, and print deliverable

A printing method in which an ink dot size formed on a medium by ejecting an ink droplet is modulated in plural levels to perform multi-gradation printing, comprising:

• ejecting ink droplets from inkjet head nozzles while moving the inkjet head nozzles in a line direction with respect to the medium;
• and
• supplying an ejection control signal to one of the nozzles for controlling ejection of the ink droplets from the one of the nozzles;
• wherein the inkjet head forms lines of ink dots in a direction perpendicular to the line direction in a juxtaposed manner, and the inkjet head forms the ink dots in each of the lines having the same color by ejecting the ink droplets from one of the nozzles corresponding to a respective line of ink dots;
• wherein the ejection control signal corresponds to a level of the ink dot size supplied to the one of the nozzles, and the one of the nozzles ejects the ink droplets depending on the ejection control signal;
• wherein control of ejection of the ink droplets is changed depending on whether the one of the nozzles for forming the respective line is an abnormal nozzle, which is characterized by an ejection error representing a difference between a volume of the ink droplet ejected and a predetermined standard value selected from a permitted range, or control of ejection of the ink droplets is changed depending on whether the one of the nozzles for forming the respective line is a normal nozzle, which is characterized by an ejection error within the permitted range;
• wherein the ejection control signal corresponding to the ink dot size for a part of the ink dots juxtaposed each other in the respective line supplied for the abnormal nozzle is different from the ejection control signal corresponding to the ink dot size for a part of the dots juxtaposed each other in the respective line formed by the normal nozzle;
• and
• wherein the ejection control signal supplied for the abnormal nozzle is different from the normal nozzle that is characterized by an average value in the respective line of the ejection errors that is minimized close to zero in comparison with a case that the ejection control signal for the normal nozzle is supplied as the ejection control signal corresponding to all of the dots in the respective line.

A manufacturing method for a printed product in which an ink dot size formed on a medium by ejecting an ink droplet is modulated in plural levels to perform multi-gradation printing in an inkjet method to manufacture a printed product, comprising:

• ejecting ink droplets from inkjet head nozzles while moving the inkjet head nozzles in a line direction with respect to the medium;
• and
• supplying an ejection control signal to one of the nozzles for controlling ejection of the ink droplets from the one of the nozzles;
• wherein the inkjet head forms lines of ink dots in a direction perpendicular to the line direction in a juxtaposed manner, and the inkjet head forms the ink dots in each of the lines having the same color by ejecting the ink droplets from one of the nozzles corresponding to a respective line of ink dots;
• wherein the ejection control signal corresponds to a level of the ink dot size supplied to the one of the nozzles, and the one of the nozzles ejects the ink droplets depending on the ejection control signal;
• wherein control of ejection of the ink droplets is changed depending on whether the one of the nozzles for forming the respective line is an abnormal nozzle, which is characterized by an ejection error representing a difference between a volume of the ink droplet ejected and a predetermined standard value selected from a permitted range, or control of ejection of the ink droplets is changed depending on whether the one of the nozzles for forming the respective line is a normal nozzle, which is characterized by an ejection error within the permitted range;
• wherein the ejection control signal corresponding to the ink dot size for a part of the ink dots juxtaposed each other in the respective line supplied for the abnormal nozzle is different from the ejection control signal corresponding to the ink dot size for a part of the dots juxtaposed each other in the respective line formed by the normal nozzle;
• and
• wherein the ejection control signal supplied for the abnormal nozzle is different from the normal nozzle that is characterized by an average value in the respective line of the ejection errors that is minimized close to zero in comparison with a case that the ejection control signal for the normal nozzle is supplied as the ejection control signal corresponding to all of the dots in the respective line.