Patent ID: 8287079
Filing Date: 2012-10-16
Classification: B41J

Abstract:
1. A landing position determining method for processing-liquid ejection nozzles used in an inkjet recording method of depositing transparent processing liquid and colored ink from the processing-liquid ejection nozzles and ink nozzles, respectively, one on top of another to form an image and fixing and recording the colored ink, the landing position determining method comprising: setting a processing liquid deposited pattern so that, by one processing-liquid ejection nozzle and a plurality of processing-liquid ejection nozzles located on both sides of the one processing-liquid ejection nozzle selected as landing position determination targets of the deposited processing liquid, a plurality of linear landing position determination target areas are formed in which the processing liquid is continuously deposited for a predetermined number of dots while gradually changing density of the processing liquid to be deposited to one of increase and decrease in one direction and a number of dots with one of high and low density of the processing liquid decreases farther away from centered linear landing position determination target area of the plurality of linear landing position determination target areas, and, by remaining processing-liquid ejection nozzles, the processing liquid is continuously deposited while the density of the processing liquid is changed in a direction opposite to a direction of the plurality of linear landing position determination target areas; ejecting the processing liquid from the processing-liquid ejection nozzles onto a recording medium to form the processing liquid deposited pattern on the recording medium according to the set processing liquid deposited pattern; depositing the colored ink from a plurality of ink nozzles, which include an ink nozzle corresponding to the selected processing-liquid ejection nozzle, and are selected, from ink nozzles on both sides of the ink nozzle, with a predetermined nozzle interval, onto the processing liquid deposited pattern, and recording a plurality of linear colored ink images to form a processing liquid landing position determination pattern on the recording medium; scanning the processing liquid landing position determination pattern formed on the recording medium with a detection sensor; detecting the plurality of linear colored ink images in the processing liquid landing position determination pattern scanned by the detection sensor; measuring at least one of densities and line widths of the detected plurality of linear colored ink images; and detecting presence/absence of a change in the at least one of the measured densities and line widths of the plurality of linear colored ink images, and determining, from at least one of density distribution and line width distribution in a linear colored ink image in which the change is present, a landing position of the processing liquid ejected from the processing-liquid ejection nozzle selected as the landing position determination targets.