Inkjet Line Head Module Switching for Overlap Uniformity
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Solution Overview
Problem
Single pass inkjet recording apparatuses experience image quality deterioration in overlapping regions due to differences in ink landing times and phase changes, leading to variations in dot height and gloss between overlapping and non-overlapping regions.
Innovation Solution
An inkjet recording apparatus with a line head comprising multiple overlapping head modules, where a recording controller coordinates ink ejection to ensure complementary operations by switching between adjacent head modules based on predetermined conditions, such as non-ejection sections of a certain length, to maintain consistent ink landing times and prevent image quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If ink ejection ports are arranged without overlapping in the conveying direction, then image quality in overlapping regions is improved, but the ejection rate decreases and recording duty increases
Solution Approach 1:
The patent dynamically switches between two head modules (first and second head modules) based on the position in the overlapping region. By alternately using different head modules for ejection in different sections, the system maintains consistent ink landing timing while utilizing all ink ejection ports, thus preserving both image quality uniformity and high ejection rate
Solution Approach 2:
The patent changes the operational parameters by switching which head module performs ejection based on position. In the overlapping region, it alternates between the first and second head modules, effectively changing the active ejection source parameter to maintain consistent ink landing characteristics while utilizing full port capacity
2Device complexity
If the time difference between ink landings on overlapping dots is large, then head module overlapping structure is simplified, but dot height and gloss uniformity deteriorate
Solution Approach 1:
The system dynamically selects which head module to use based on position within the overlapping region. By switching between first and second head modules at appropriate positions, it maintains consistent ink landing timing (small time difference) while preserving the simplified overlapping head structure, thus achieving both structural simplicity and dot height uniformity
3Manufacturing precision
If complementary ink ejection operations are implemented by switching between head modules, then image quality uniformity is improved, but control complexity increases
Solution Approach 1:
The patent applies different control strategies for different regions: in non-overlapping regions, standard ejection is used, while in overlapping regions, head module switching is implemented. This localized approach maintains image quality uniformity in the critical overlapping region while minimizing overall control complexity by not applying complex switching everywhere
Solution Approach 2:
The recording width direction is segmented into different regions (non-overlapping and overlapping regions), and different head modules are assigned to different segments. This segmentation allows systematic control of ink ejection to maintain uniformity while managing control complexity through structured regional division
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively prevents image quality deterioration in overlapping regions by ensuring consistent ink ejection and dot formation, reducing gloss differences and maintaining uniformity across the image, even with phase change inks.
Implementation Method 1
the phase change of ink proceeds during the time between 25 msec and 100 msec after ink landing on the recording medium
Data Source
AI summary
An inkjet recording apparatus includes: a recorder having a line head, the recorder ejecting ink through each of the ink ejection ports toward a recording medium; a mover that moves the recording medium and the line head relative to each other in a direction intersecting the arrangement direction of the ink ejection ports in the line head, and causes each pair of ink ejection ports of two adjacent head modules facing each other in the overlapping region to pass through a same place on the recording medium; and a recording controller that controls ink ejection operations of the plurality of head modules on the recording medium in accordance with dot data, and causes either of a pair of ink ejection ports of two adjacent head modules to eject ink to implement complementary ink ejection operations by the pair of ink ejection ports of the two head modules.