Continuous Web Registration Correction via Dynamic Line Spacing
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Solution Overview
Problem
Inkjet printing systems face challenges in maintaining accurate color-to-color registration, especially when printing multiple documents consecutively without gaps, leading to visible artifacts and registration errors due to physical properties of the print medium, conveyance methods, ink application, and drying processes.
Innovation Solution
A method for correcting image plane registration errors in multi-channel printing systems by measuring and adjusting the in-track line spacing of printheads in real-time, allowing for continuous printing without gaps between documents, using a combination of nominal and adjusted line spacings to maintain registration accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If registration corrections are made by shifting the start position of image planes, then registration accuracy is improved, but visible artifacts appear at document seams when printing multiple documents consecutively without gaps
Solution Approach 1:
The patent applies dynamics by transitioning from static registration correction (fixed start position shift) to dynamic correction (continuous adjustment of line spacing during printing). The system dynamically modifies the in-track line spacing of affected color planes during the printing process itself, allowing registration correction to occur mid-document without creating visible artifacts at document boundaries.
Solution Approach 2:
The patent changes the parameter being adjusted from start position offset to in-track line spacing. By modifying the line spacing parameter continuously during printing rather than applying a fixed positional shift, the system achieves registration correction without creating discontinuities or visible artifacts at document seams.
2Manufacturing precision
If conventional registration correction methods are used with intervening non-print gaps, then registration accuracy is improved, but productivity decreases due to required gaps between documents
Solution Approach 1:
The patent enables continuous printing without intervening non-print gaps by performing registration correction dynamically during the printing process itself. This eliminates the need to stop printing and insert gaps for registration adjustments, maintaining continuous useful action and thereby improving productivity while preserving registration accuracy.
3Manufacturing precision
If in-track line spacing is adjusted during correction time interval, then registration errors are corrected without artifacts, but device complexity increases due to real-time spacing adjustment mechanism
Solution Approach 1:
The patent implements feedback by measuring in-track registration errors and using this information to dynamically adjust the in-track line spacing of affected color planes. The system continuously monitors registration accuracy and modifies printing parameters in real-time based on measured errors, enabling artifact-free correction without requiring complex mechanical intervention.
Solution Approach 2:
The patent replaces potential mechanical adjustment mechanisms with digital control of printing parameters. Instead of physically adjusting printhead positions or spacing mechanisms, the system uses software-controlled modification of line spacing data, substituting mechanical complexity with computational control.
Data Source
AI summary
Image plane registration errors are corrected for a multi-channel printing system that prints on a continuous web of media. Nominal in-track line spacing are defined for each image plane, and are used to print lines of image data for each image plane. An in-track registration error is measured for a misregistered image plane in the printed image, and is used to determine an adjusted in-track line spacing that will bring the misregistered image plane back into registration in the in-track direction over a predefined correction time interval. Additional image data is then printed using the adjusted in-track line spacing during the correction time interval, after which image data is printed using a new in-track line spacing that is different from the adjusted in-track line spacing.