Continuous Inkjet Drop Velocity Adjustment for Synchronization Band Reduction
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Solution Overview
Problem
Continuous inkjet printers face challenges in maintaining consistent drop spacing and synchronization with pixel rates at varying print speeds, leading to visible synchronization bands due to inconsistent air drag on print drops, which affects print quality.
Innovation Solution
The method involves adjusting the velocity of print drops relative to catch drops using velocity modifying pulses to align print drops within pixel locations, reducing the visibility of synchronization bands by altering the impact position of drops through changes in activation pulse energy and timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous inkjet printers operate at varying print speeds, then productivity is improved, but drop placement precision deteriorates due to inconsistent air drag and synchronization bands
Solution Approach 1:
The patent applies dynamics by making the drop generation frequency variable rather than fixed. The system continuously adjusts the drop generation frequency to match the pixel rate at different print speeds, allowing the printer to maintain synchronization between drop formation and media movement across varying productivity levels, thereby preventing synchronization bands while preserving drop placement precision
Solution Approach 2:
The patent changes the parameter of drop generation frequency dynamically. By adjusting this frequency parameter in response to varying print speeds and corresponding pixel rates, the system maintains optimal drop placement precision across different productivity conditions, eliminating the synchronization bands that would otherwise appear at certain speed thresholds
2Device complexity
If drop generation frequency is fixed, then device complexity is reduced, but adaptability deteriorates because synchronization bands appear at certain print speeds
Solution Approach 1:
The system transitions from a static drop generation frequency to a dynamic one that adapts to different print speeds. This dynamic adjustment allows the printer to maintain synchronization across a wide range of print speeds without requiring complex mechanical adjustments, achieving high adaptability through electronic control while keeping the overall device complexity manageable
Solution Approach 2:
The patent changes the operational parameter of drop generation frequency to enable adaptability across different print speeds. This parameter change allows the system to avoid synchronization bands at various speeds while maintaining a relatively simple device architecture, as the adjustment is achieved through control logic rather than mechanical complexity
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 ensures consistent drop placement and reduced visibility of synchronization bands, enhancing print quality by maintaining uniform drop spacing across different print speeds.
Implementation Method 1
stimulation devices perturb the liquid streams emanating from the associated nozzle or nozzles in response to drop formation waveforms supplied to the stimulation devices
Implementation Method 2
A drop deflection means applies a force to the drops to cause the drop trajectories to separate based on the size of the drops
Data Source
AI summary
A method for providing drop placement adjustment of drops deposited on a print media by a printhead in a continuous inkjet printer, the method comprising the steps of providing the printhead with a drop generator having at least one nozzle; moving the printhead relative to the print media; causing the printhead to form drops from the at least one nozzle with a drop formation period being the time between consecutive drop formations; wherein a portion of the formed drops are allowed to strike pixel locations on the print media for forming print drops, while other drops are directed toward a catcher and do not strike the print media for forming catch drops; creating a series of the print drops to print on a series of consecutive pixel locations; and adjusting a velocity of a portion of the formed print drops relative to a velocity of other print drops to adjust the placement of the print drop within the pixel locations.