Inkjet Nozzle Back-and-Forth Motion for Streak Masking
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Solution Overview
Problem
Inkjet printing technologies face issues with streakiness and nozzle failures, particularly when producing raised coatings, due to nozzle deviations and manufacturing inaccuracies, which reduce productivity and image quality.
Innovation Solution
A method involving periodic or statistical back-and-forth movement of inkjet nozzles, combined with precise position detection and adjustment, to minimize streaks and compensate for nozzle failures, using a polymer coating applied with inkjet nozzles that can be moved individually or in groups, and cured to form a solid layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If inkjet printheads are used with fixed nozzle positions, then productivity is improved through single-pass printing, but streakiness and nozzle failure become more noticeable
Solution Approach 1:
The patent applies dynamics by moving the inkjet printhead in a back-and-forth motion during the printing process. This dynamic movement transforms the static nozzle positions into moving targets, causing streaks to appear discontinuous and masking the effects of individual nozzle failures. The printhead displacement is controlled to be within a specific range (0.1-10 times the nozzle spacing) to achieve this effect.
Solution Approach 2:
The patent implements periodic action through the systematic back-and-forth movement of the printhead at regular intervals during continuous substrate feeding. This periodic displacement creates a statistical distribution of droplet positions that prevents regular streaking patterns and compensates for nozzle imperfections over time.
2Manufacturing precision
If statistical nozzle selection is used to mask streaks, then image quality improves, but device complexity increases
Solution Approach 1:
Instead of using complex statistical selection algorithms, the patent employs a simple mechanical dynamic approach where the printhead physically moves back and forth during printing. This mechanical movement naturally creates statistical distribution of droplet positions without requiring complex control systems to select nozzles randomly or alternately.
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 streakiness and conceals nozzle failures, maintaining image quality and productivity by ensuring accurate drop placement and pattern formation, even with small nozzle movements.
Implementation Method 1
the inkjet nozzles dispense a fluid application material drop by drop
Implementation Method 2
the film is cured to form a solid polymer coating after application
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
In order to prevent streaks during the ink-jet paint coating of substrates, a method is provided for printing sheet-type substrates, in which - a substrate (3) is moved in a feed direction (4) past an application device (7) by means of a conveying device (5) and - as the substrate is being moved, the application device (7) applies a liquid application material (9) drop-by-drop to the surface (30) of the substrate (3) in a pattern (14) with a pre-defined contour (15), in particular leaving out regions (16), through multiple ink-jet nozzles (70) arranged in a row transversely to the feed direction, in response to computer-controlled activation signals, wherein - during the application of the pattern (14) and during the movement of the substrate (3) the ink-jet nozzles (70) are moved back-and-forth transversely to the feed direction (4), preferably in the longitudinal direction of the arranged row of ink-jet nozzles (70), such that the paths (72) travelled by the nozzles (70) over the substrate by the overlap of the back-and-forth movement with the movement in the feed direction (4) have direction components running perpendicular to the feed direction (4).