Non-printed Encoder Marks for Web Press Dot Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In digital printing systems, especially web presses used in commercial applications, precise dot placement in the down-web direction is challenging due to media expansion and contraction caused by water content and tension changes, leading to inaccurate image quality, as existing techniques like metering rollers, virtual encoders, and calibration runs are either inaccurate or wasteful.
Innovation Solution
A printing system that uses an encoding station to form non-printed features like holes or bumps on the media, which serve as encoder marks and indicia, allowing downstream printing stations to detect these features and generate timing signals for precise dot placement, adjusting for media expansion and contraction to maintain desired print resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metering rollers are used to control dot placement, then some level of positioning control is achieved, but accuracy is insufficient for high-quality printing
Solution Approach 1:
The patent replaces mechanical measurement systems (metering rollers) with an optical encoding system. Non-printed features (holes or bumps) are optically detected by sensors, and timing signals generated from these detections control dot placement, eliminating the inaccuracies of mechanical roller-based positioning.
Solution Approach 2:
The patent introduces non-printed features (holes or bumps) as intermediary reference markers between the media and the detection system. These features serve as precise positional references that are detected optically, enabling accurate timing signal generation for dot placement without direct mechanical contact or measurement.
2Manufacturing precision
If printed marks are used as encoder marks, then dot placement can be controlled, but valuable printing space is consumed
Solution Approach 1:
The patent extracts the encoding function from the printable area by using non-printed features (holes or bumps) instead of printed marks. These physical features are formed on the media but do not consume ink or printable space, allowing full utilization of the media surface for actual content while maintaining precise positioning control.
Solution Approach 2:
The non-printed features serve as intermediary reference elements that provide positioning information without being part of the printed content. They are detected by optical sensors and used to generate timing signals, separating the positioning function from the printing function and eliminating space consumption.
3Manufacturing precision
If calibration runs are performed to adjust for media expansion, then print resolution can be maintained, but time and resources are wasted
Solution Approach 1:
The patent performs preliminary positioning by forming non-printed features on the media before the actual printing process. These features establish precise reference points that enable real-time timing signal generation, eliminating the need for separate calibration runs and allowing immediate high-resolution printing.
Solution Approach 2:
The system uses the media itself (with non-printed features) to provide positioning information, making the media self-referential for timing and placement control. This eliminates the need for external calibration processes, as the non-printed features continuously provide reference data for dot placement throughout the printing run.
4Measurement precision
If non-printed features are used for encoding, then precise timing signals can be generated, but additional processing steps are required
Solution Approach 1:
The patent replaces complex mechanical encoding mechanisms with a simpler optical detection system. Non-printed features (holes or bumps) are detected by optical sensors that generate timing signals based on light interaction, eliminating the need for complex mechanical encoding devices while achieving high measurement precision.
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 enables accurate and efficient down-web dot placement, maintaining high print resolution and image quality by accounting for media expansion and contraction, without the need for wasteful calibration runs or space-consuming printed marks, thus improving the perceived quality and efficiency of the printing process.
Implementation Method 1
The printing station detects the non-printed features on the patterned media
Implementation Method 2
media expansion and contraction to maintain desired print resolution
Data Source
AI summary
In one example, an encoding station of a printing system forms a pattern of non-printed features onto flowing print media. The non-printed features are detected, and timing signals generated from the detected features. The timing signals cause the media to be printed at a desired resolution in the direction of the flow.