Patent ID: 9085169
Filing Date: 2015-07-21
Classification: B41J

Abstract:
1. An inkjet printing apparatus configured to perform printing by discharging ink droplets onto a print medium, the apparatus comprising: a printing head having a plurality of inkjet heads and configured to perform printing by discharging the ink droplets from the plurality of inkjet heads onto the print medium; a chart printing device configured to print a step-shift correcting chart with the printing head, the step-shift correcting chart having a plurality of lines orthogonal to the transportation direction and a blank area separating the plurality of lines and being used for correcting step shift as printing shift of the plurality of inkjet heads in a transportation direction; a reading device configured to read the step-shift correcting chart printed on the print medium; a print medium-processed portion detecting device configured to detect a processed portion of the print medium formed in a direction orthogonal to the transportation direction of the print medium in accordance with the blank area; an uninfluenced step-shift correcting-chart generating device configured to eliminate an influence of the processed portion of the print medium detected by the print medium-processed portion detecting device from the step-shift correcting chart read by the reading device, thereby generating an uninfluenced step-shift correcting chart; and a shift-amount calculating device configured to calculate a shift amount for correcting the step shift in accordance with the uninfluenced step-shift correcting chart.