Inkjet Printing Apparatus Nozzle Array Position Shift Correction
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Solution Overview
Problem
Inkjet printing apparatuses face challenges in maintaining consistent printing positions due to variations in the conveyance speed of the print medium, leading to shifts in printed dots, which existing methods struggle to address effectively.
Innovation Solution
The apparatus includes a correcting unit that determines a correction value based on an inspection pattern printed on the preceding region of the print medium, allowing for precise adjustment of printing positions between nozzle arrays to correct shifts in subsequent regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the amount of conveyance of the print medium per unit time is varied by conditions of the conveying unit and the print medium, then the printing position shift occurs between print heads, but the existing registration adjustment methods cannot effectively address this issue
Solution Approach 1:
The invention performs registration adjustment in advance by using inspection patterns printed before the actual image printing. The correction values are determined based on inspection patterns in preceding regions, and these correction values are applied to compensate for printing position shifts caused by conveyance variations during the actual printing process.
Solution Approach 2:
The invention implements a feedback mechanism where inspection patterns are printed and measured to determine actual printing positions, correction values are calculated based on the deviation from expected positions, and these correction values are then applied to adjust the timing of subsequent ink ejection. This closed-loop feedback system continuously adapts to conveyance variations.
2Ease of operation
If null data is added to print data to adjust ink ejection timing, then the ink ejection timing can be adjusted, but the interval in each nozzle array cannot be set in an arbitrary manner
Solution Approach 1:
The invention makes the null data addition dynamic rather than static. The amount of null data added is not fixed but is determined in real-time based on the actual printing position deviations measured from inspection patterns. This allows the system to adapt to different nozzle array intervals and conveyance conditions dynamically.
Solution Approach 2:
The invention changes the parameter of null data addition amount based on measured printing position deviations. By calculating correction values from inspection patterns and adjusting the number of null data entries accordingly, the system can achieve arbitrary nozzle array interval settings while maintaining precise ink ejection timing.
3Manufacturing precision
If registration adjustment is performed at the timing when a change in ink ejection speed is detected, then the ink ejection speed change can be addressed, but the printing position shift caused by conveyance variation cannot be effectively corrected
Solution Approach 1:
The invention performs the time-consuming inspection and correction value determination in advance, before the actual image printing begins. By measuring inspection patterns and calculating correction values beforehand, the system eliminates the need for time-consuming registration adjustments during the printing process, thus not losing time while achieving precise position correction.
Data Source
AI summary
A printing apparatus, including: printing unit; conveying unit; print control unit; correcting unit configured to determine, in printing an image on each of a plurality of sets of the same type of print medium, a correction value for correcting printing position shift between a plurality of nozzle arrays based on an inspection pattern printed on a preceding region of the print medium, and to correct the printing position between the plurality of nozzle arrays in the subsequent region of the print medium by using the determined correction value, wherein the correcting unit corrects, in printing on a leading end region of a set of print medium subsequent to the preceding set of print medium, the printing position shift by using the correction value used in printing on the preceding set of print medium.