Patent ID: 6692096
Filing Date: 2004-02-17
Classification: B41J

Abstract:
A bi-directional printing apparatus that bi-directionally prints images on a print medium during forward and reverse main scanning passes in accordance with print image signals the printing apparatus comprising:a print head configured to print dots at each pixel position on the print medium; a main scanning drive mechanism configured to effect bi-directional main scanning by moving at least one of the print medium and the print head; a sub-scanning drive mechanism configured to effect sub-scanning by moving at least one of the print medium and the print head; a head driver configured to supply drive signals to the print head to effect printing on the print medium; and a controller configured to control bi-directional printing the controller including a printing position adjuster that uses an adjustment value to reduce printing positional deviation arising between the forward and reverse main scanning passes, wherein the printing position adjuster includes: a first memory configured to store a reference correction value for correcting the printing positional deviation arising between the forward and reverse main scanning passes with respect to specific reference dots formed by the print head, a second memory configured to store a relative correction value prepared beforehand for correcting the reference correction value, and an adjustment value determination section configured to determine the adjustment value, the adjustment value determination section having a first adjustment mode in which the adjustment value is determined by correcting the reference correction value with the relative correction value and a second adjustment mode in which the reference correction value is used as the adjustment value, and wherein the print head has a plurality of nozzle rows; the reference correction value is a correction value for correcting the printing positional deviation arising between the forward and reverse main scanning passes with respect to a reference row of nozzles; and the relative correction value is a correction value for correcting a relative printing positional deviation of another row against the reference row.