Two-Pass Inkjet Printing for Wind-Related Print Defects
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Solution Overview
Problem
Inkjet printers face wind-related print defects, such as swath contraction and non-uniform horizontal intraswath banding, due to aerodynamic and fluidic interactions, particularly in high-resolution printing where nozzles are spaced closer together and operate at higher frequencies, leading to severe print quality issues in monochromatic modes.
Innovation Solution
Implementing a two-pass print mode where only half of the nozzles in each column are utilized during a given pass, creating gaps for air flow and minimizing wind-related defects without reducing swath height, which would decrease print speed, by alternating nozzle usage in subsequent passes to cover the entire swath.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If nozzles are spaced closer together and operate at higher frequencies to increase resolution, then printing resolution is improved, but wind-related print defects worsen
Solution Approach 1:
The patent divides the array of nozzles into multiple groups, where each group contains a subset of nozzles. During printing, only one group is activated at a time while other groups remain inactive, creating temporal segmentation of nozzle operation. This segmentation reduces the number of simultaneously active nozzles, thereby reducing aerodynamic interactions and wind-related defects while maintaining high resolution capability when all groups are used across multiple passes.
2Object-affected harmful factors
If swath height is reduced to minimize wind-related defects, then print quality is improved, but print speed decreases
Solution Approach 1:
The patent introduces a temporal dimension to the printing process by implementing multi-pass printing with group-based nozzle activation. Instead of reducing swath height (spatial solution), the invention uses time-based segmentation where different nozzle groups are activated in different passes. This allows the full swath height to be utilized while maintaining quality, as the reduced number of simultaneously active nozzles per pass minimizes wind-related defects without sacrificing print speed.
3Productivity
If all nozzles are utilized simultaneously to maintain print speed, then productivity is maintained, but aerodynamic interactions increase
Solution Approach 1:
The patent implements periodic action by cycling through different nozzle groups across multiple printing passes. Each nozzle group is activated periodically rather than continuously, with the activation pattern repeating across passes. This periodic utilization ensures that all nozzles contribute to the final print output (maintaining productivity) while the staggered activation schedule reduces the number of simultaneously active nozzles, thereby reducing aerodynamic interactions and wind-related defects.
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 approach effectively reduces wind-related print defects by simulating a reduced swath height without slowing down the printing process, enhancing print quality by minimizing aerodynamic effects and maintaining high print speed.
Implementation Method 1
aerodynamic forces and fluidic interactions from neighboring nozzles more adversely affect nozzles that are spaced closer together
Implementation Method 2
aerodynamic forces and fluidic interactions from neighboring nozzles more adversely affect nozzles that are spaced closer together
Data Source
AI summary
A two pass print mode method and apparatus limits wind-related print defects produced during printing, utilizing a reciprocating carrier of a printer carrying a printhead having an array of columns of actuator-fired fluid-jetting nozzles along a bi-directional scanning path. Due to instructions from a controller, printing proceeds along an initial partial swath on a print medium during a first pass along the scanning path by firing actuators associated with a first plurality of segments of a given column of nozzles. Then, printing proceeds along a final partial swath on the print medium during a second pass along the scanning path by firing actuators associated with a second plurality of segments of the given column of nozzles. Each segment of nozzles of the first and second pluralities includes more than one consecutive nozzle so that gaps are created in the partial swath printing accommodating wind-related effects without causing wind-related print defects.