Print Engine Pixel Array Compensation for Failing Nozzles
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Solution Overview
Problem
Existing reproduction apparatuses face delays and productivity losses due to the need for extensive image processing when detecting failing print elements, leading to printed images with artefacts.
Innovation Solution
Deriving arrays of pixel values in advance to replace failing print elements, using adjacent or redundant print elements for compensation, and arranging these arrays in matrices for efficient retrieval and printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If image processing is performed during printing to detect and compensate for failing print elements, then print quality is improved, but printing speed and productivity deteriorate due to processing delays
Solution Approach 1:
The patent pre-calculates and stores compensation pixel values in lookup tables before printing begins. When a print element failure is detected, the system simply retrieves pre-computed compensation data from memory rather than performing real-time image processing during printing. This eliminates processing delays while maintaining print quality correction.
2Manufacturing precision
If real-time image processing is performed to correct failing print elements, then print artefacts are reduced, but processing time increases causing productivity loss
Solution Approach 1:
Compensation pixel values are pre-computed and stored in lookup tables before printing operations begin. The system performs the computationally intensive image processing work in advance, then only requires simple memory retrieval during printing. This eliminates processing time delays while maintaining artefact reduction.
Solution Approach 2:
The patent creates lookup tables that contain pre-computed compensation data representing corrected pixel values. Instead of performing complex image processing during printing, the system copies pre-prepared compensation data from the lookup tables into the print buffer, significantly reducing processing time while maintaining correction effectiveness.
3Manufacturing precision
If extensive image processing is performed during printing to compensate for failing print elements, then compensation accuracy is improved, but device complexity and processing overhead increase
Solution Approach 1:
The system pre-computes compensation pixel values and stores them in lookup tables before printing begins. During printing, the system only needs to retrieve pre-computed values based on detected failure patterns, significantly reducing processing complexity while maintaining compensation accuracy.
Solution Approach 2:
The patent uses lookup tables that contain pre-computed compensation data. Instead of performing complex real-time calculations, the system copies pre-prepared compensation values from the lookup tables into the print buffer, simplifying the printing process while maintaining accurate compensation.
Data Source
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AI summary
The invention concerns a reproduction apparatus for printing a digital image comprising a control unit and a print engine, where the digital image is constituted of pixels, each pixel having assigned a pixel value; the print engine comprising print elements for ejecting an amount of marking material on a receiving material according to a pixel value, the reproduction apparatus further comprising detection means for detecting a failing print element and the control unit comprising derivation means for deriving from the digital image before printing of the digital image for a print element at least one array of pixel values to be printed upon detection of a failing of said print element by the detection means by at least one other print element, and merging means for merging at least one of said at least one array of pixel values with the digital image upon detection of a failing print element for creating a corrected digital image to be printed. The invention also concerns a method for printing a digital image on a reproduction apparatus according to the invention.