Tone-Level Correction in Digital Printers via Time-Position Vectors
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Solution Overview
Problem
Digital printing systems, particularly electrophotographic printers, face challenges in correcting tone-level non-uniformities that vary with time and position, leading to artifacts like image streaks, which existing methods fail to address effectively.
Innovation Solution
A method involving the use of digital image data and a data processing system to analyze tone-level errors in test targets, determining a tone-level correction function that specifies corrections based on cross-track position, pixel value, and time, and applying these corrections to input image data to reduce tone-level errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a tone-level correction function is stored in full resolution, then correction accuracy is improved, but memory storage requirements increase
Solution Approach 1:
The correction function is segmented into multiple component functions, each representing a specific aspect of tone-level variation (e.g., cross-track position dependence, in-track position dependence, time dependence). These segmented functions are stored separately and combined during correction, reducing individual storage requirements while maintaining overall correction accuracy.
Solution Approach 2:
The correction approach transitions from storing a single high-dimensional correction table to storing multiple lower-dimensional component functions. By decomposing the correction function into dimensions corresponding to different physical parameters (position, time, pixel value), the system achieves comparable correction accuracy with reduced storage requirements.
2Adaptability or versatility
If correction functions account for multiple variables (position, time, pixel value), then correction comprehensiveness is improved, but system complexity increases
Solution Approach 1:
The comprehensive correction function is segmented into multiple independent component functions, each handling a specific variable or interaction. This segmentation allows the system to manage complexity by treating each component separately while achieving comprehensive correction when components are combined.
Solution Approach 2:
The correction system is designed with universal component functions that can handle multiple correction scenarios. Each component function serves multiple purposes depending on the correction context, reducing the need for separate specialized functions for each correction case.
Data Source
AI summary
A method for correcting tone-level non-uniformities in a digital printing system includes printing a test target having a set of uniform test patches. The printed test target is automatically analyzed to determine tone-level errors as a function of cross-track position for each of the test patches. A tone-level correction function is determined and represented using a set of one-dimensional feature vectors which specifies tone-level corrections as a function of cross-track position, pixel value and time. Corrected image data is determined by using the tone-level correction function to determine a tone-level correction value for each image pixel responsive to the input pixel value, cross-track position and time. The corrected image data is printed using the digital printing system to provide a printed image with reduced tone-level errors.