Continuous Paper Printing Alignment Under Ink-Induced Web Stretch
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Solution Overview
Problem
Conventional ink-jet type color printing apparatuses experience misregistration of print positions among multiple print sections, leading to deteriorated print quality, especially in double-sided printing, due to ink attachment causing base material extension and deviation of print positions.
Innovation Solution
A printing apparatus that includes a transport section, print sections, an ink amount estimator, a deviation amount obtaining section using machine learning, and a print control section to adjust print positions based on estimated ink amounts and detected tension, ensuring precise alignment of print positions across multiple print sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple print sections are used to eject ink in turn, then color printing capability is improved, but print position deviation occurs among different colors
Solution Approach 1:
The system performs preliminary detection of print position deviations using detection charts before actual printing. The deviation amount is calculated in advance based on the detected positions, and correction values are pre-computed for each print section. This preliminary action allows the system to compensate for inevitable deviations when ink is ejected from multiple print sections in sequence.
Solution Approach 2:
The system incorporates feedback mechanisms where detection charts are printed and scanned to measure actual print positions. The measured deviations are fed back into the control system, which then adjusts the timing and positioning of subsequent ink ejection. This closed-loop feedback ensures continuous improvement of print position accuracy across all color layers.
2Adaptability or versatility
If ink is ejected from multiple print sections in sequence, then complete color images can be formed, but the base material extends due to ink attachment causing misregistration
Solution Approach 1:
The system calculates the extension amount of the base material in advance based on the ink ejection amounts from previous print sections. This preliminary calculation allows the system to compensate for the material extension before it causes misregistration, by adjusting the timing and position of subsequent ink ejection accordingly.
Solution Approach 2:
The system dynamically changes timing parameters and position parameters of ink ejection based on the detected extension amount. By modifying these parameters in response to the base material extension caused by ink attachment, the system maintains precise alignment across all color layers despite the physical changes in the base material.
3Device complexity
If conventional control methods are used, then device complexity is reduced, but print quality deteriorates due to uncorrected misregistration
Solution Approach 1:
The system introduces detection charts as intermediary elements that facilitate the measurement of print position deviations. These charts serve as mediators between the printing system and the quality control system, enabling precise measurement without requiring complex real-time monitoring of each print section's output.
Solution Approach 2:
The system replaces complex mechanical adjustment mechanisms with an information-based control approach. Instead of using complex mechanical systems to physically adjust print positions, the system uses detected deviation data to compute correction values and adjust timing parameters, substituting mechanical complexity with computational precision.
Data Source
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AI summary
A transport section transports a continuous printing paper in a predetermined transport direction. A first print section ejects first ink to the printing paper. A second print section is provided in a downstream side of the first print section in the transport direction, and ejects second ink to the printing paper. An ink amount estimating section estimates an amount of ink ejected to the printing paper from before printing by the first print section to before printing by the second print section, based on print data. A deviation amount obtaining section obtains a deviation amount between a print position by the first print section and a print position by the second print section at least based on the estimated ink amount. A print control section controls the print position by the second print section based on the deviation amount.