Swapping Dot Data for High-Speed Monochrome Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-speed monochrome printheads using Memjet technology face limitations in achieving a wide range of print modes due to fixed nozzle firing frequencies and dot pitch variations when printing at different resolutions and speeds, resulting in noticeable artefacts and reduced print quality.
Innovation Solution
The method involves using printheads with trapezoidal-shaped dropped nozzle regions and implementing ramped dot data and mismatched nozzle rows to compensate for dot placement errors, allowing for improved alignment and reduced artefacts across different print modes by swapping dot data between main and dropped nozzle regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fixed vertical offset of dropped nozzle region is used, then seamless printing is achieved at 1600 dpi, but dot placement errors occur at other resolutions
Solution Approach 1:
The patent applies dynamics by making the offset compensation value variable rather than fixed. The dropped nozzle region's offset is dynamically adjusted based on the actual print resolution being used, allowing the system to adapt to different print modes (1600 dpi, 1200 dpi, 800 dpi, 400 dpi) while maintaining dot placement accuracy across all resolutions
Solution Approach 2:
The patent changes the parameter of offset compensation from a fixed value (10 dot pitches) to a variable value that depends on print resolution. By calculating and applying resolution-specific offset values, the system maintains manufacturing precision across multiple print modes, resolving the contradiction between fixed design and adaptive performance
2Productivity
If maximum firing frequency is used, then print speed is maximized, but print resolution flexibility is reduced
Solution Approach 1:
The system dynamically adjusts the relationship between firing frequency and offset compensation based on the desired print resolution. By making the compensation value variable rather than fixed, the system can operate at maximum firing frequency for high-speed printing while still achieving accurate dot placement at various resolutions through resolution-appropriate offset values
3Ease of manufacture
If dropped nozzle region is used, then print chip butting is enabled, but dot pitch variation occurs at join regions
Solution Approach 1:
The patent applies parameter changes by adjusting the offset compensation value based on print resolution to maintain dot pitch consistency across join regions. By calculating resolution-specific offset values, the system compensates for the physical separation in dropped nozzle regions, ensuring uniform dot pitch throughout the printed output regardless of print chip butting
Data Source
Figure 1~3
Figure 4~5B
AI summary
A method of printing an image from a printhead module having a plurality of horizontal nozzle rows. The method includes the steps of: allocating first dot data for an image line of the image to nozzles in a main row portion of a first nozzle row; allocating second dot data for the image line to nozzles in a dropped row portion of the first nozzle row; sending the first and second dot data to the printhead module and firing respective droplets. Some bits of the first dot data correspond to pixels of the image line aligned with the dropped row portion, and some bits of the second dot data correspond to pixels of the image line aligned with the main row portion.