Inkjet Printer Color Conversion Table Selection for Multipass Uniformity
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Solution Overview
Problem
Multipass printing in ink jet printers often results in color changes due to between-pass time gaps, which existing techniques struggle to fully suppress, leading to darker or uneven print quality.
Innovation Solution
A printing control device and method that utilizes multiple color conversion tables based on position data and scanning paths to select the appropriate color conversion table for each printing operation, allowing for interpolation to compensate for time gaps and prevent color changes, thereby ensuring consistent print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multipass printing is performed with a between-pass time gap, then the printing process can be completed, but color change occurs and print quality becomes uneven
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing multiple color conversion tables corresponding to different between-pass time gaps before printing. The control device determines the actual time gap in advance and selects the appropriate color conversion table to compensate for color changes, rather than attempting correction after the fact.
Solution Approach 2:
The patent changes the parameter of color conversion by using multiple color conversion tables with different conversion characteristics. Each table is optimized for a specific between-pass time gap, allowing the system to adjust the color conversion parameters based on the actual time gap measured during printing.
2Manufacturing precision
If a single color conversion table is used for multipass printing, then the device complexity is low, but color change cannot be suppressed
Solution Approach 1:
The patent segments the color conversion function by dividing it into multiple discrete color conversion tables, each handling a specific between-pass time gap range. This segmentation allows the system to address different color change scenarios with specialized conversion tables rather than using a single generic table.
Solution Approach 2:
The patent implements feedback by measuring the actual between-pass time gap during printing and using this information to select the appropriate color conversion table. The control device continuously monitors the time gap and adjusts the color conversion table selection accordingly, creating a closed-loop system that adapts to actual printing conditions.
3Quantity of substance
If the amount of jetted ink is uniformly reduced, then the print darkness can be controlled, but color change due to between-pass time gap cannot be suppressed
Solution Approach 1:
The patent applies local quality by adjusting the color conversion specifically for regions affected by between-pass time gaps rather than uniformly reducing ink amount across the entire print. The color conversion tables are designed to compensate for color changes in the specific areas where time gaps occur, maintaining ink amount while correcting color consistency.
Data Source
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AI summary
In S200 after the first halftone, a scanning path is determined. In S205, a printing region to undergo multipass printing is fragmented. In S210, a printing time gap between the first printing time and the second printing time is calculated in the printing position. In S215, the position of the scanning path is associated with information on a color conversion table corresponding to the time gap. In the subsequent second color conversion, the color conversion table for use in color conversion is switched to the color conversion table corresponding to the time gap by using information on the pre-specified position of the scanning path and information on the color conversion table.