Nozzle Array Halftone Data Assignment for Inkjet Printers
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Solution Overview
Problem
Ink jet printers face image degradation due to nozzle clogging, leading to missing dots, which existing technologies struggle to fully address and improve image quality during complementation.
Innovation Solution
A printing apparatus that divides a nozzle array into groups and assigns halftone data using preset ratios to ensure that ink is discharged from multiple nozzles, allowing for effective complementation of missing dots and uniform image quality across the print substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If halftone data is assigned to each nozzle group using a preset ratio, then image quality is improved through uniform distribution, but missing dots cannot be complemented when abnormal nozzles are present
Solution Approach 1:
The patent dynamically adjusts the halftone data assignment ratio based on the operational status of nozzles. When an abnormal nozzle is detected, the system automatically modifies the assignment ratios for remaining nozzles to compensate for the missing dots, transitioning from a static preset ratio to a dynamic adaptive ratio system.
Solution Approach 2:
The system changes the assignment ratio parameter from a fixed preset value to a variable value that adapts based on nozzle performance. By detecting abnormal nozzles and recalculating the assignment ratios, the system optimizes ink distribution to maintain image quality while compensating for nozzle failures.
2Device complexity
If a single nozzle group is used for printing, then the printing process is simple, but image quality deteriorates due to missing dots from abnormal nozzles
Solution Approach 1:
The patent merges multiple nozzle groups to work together on the same printing task. When an abnormal nozzle is detected in one group, the system redistributes its assigned halftone data to other functional nozzle groups, effectively combining their output to compensate for the defective nozzle and maintain image quality.
Solution Approach 2:
Nozzle groups are designed to perform multiple functions - their primary function is normal printing, but they also serve as backup compensators when other nozzles fail. This multi-functionality allows any functional nozzle group to compensate for abnormalities in other groups, improving system reliability.
3Reliability
If halftone data is redistributed to compensate for abnormal nozzles, then missing dots are complemented, but image quality may deteriorate due to uneven distribution
Solution Approach 1:
The patent applies local quality adjustment by modifying halftone data assignment specifically for regions affected by abnormal nozzles, while maintaining normal assignment ratios for unaffected areas. This localized compensation approach ensures that image quality is maintained uniformly across the entire print output without introducing new artifacts.
Data Source
AI summary
A printing apparatus includes a printing head that includes a nozzle array, and a discharging control unit. The nozzle array is divided into a plurality of nozzle groups that is configured by a predetermined number of nozzles. The discharge control unit, when an abnormal nozzle having abnormal function of discharging the ink is included in any of the plurality of nozzle groups in a case of discharging the ink to a band area from the nozzle of each of the plurality of nozzle groups by assigning halftone data to the nozzle of each of the plurality of nozzle groups, assigns the halftone data assigned to the abnormal nozzle to the nozzle that is included in other pluralities of nozzle groups which are not the nozzle group including the abnormal nozzle according to a ratio that is a preset assignment ratio for each of the other pluralities of nozzle groups.