Ceramic Tile Printhead Calibration via Control Zone Anomaly Detection
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Solution Overview
Problem
Digital printing of ceramic tiles faces challenges in achieving uniformity among printheads, leading to incorrect color reproduction in calibration targets, which affects the quality of subsequent printed images.
Innovation Solution
A method involving the printing of control zones alongside colored zones on a ceramic tile, where control zones are measured for anomalies to determine print uniformity, and only if uniform, the colored zones' measurements are processed to create a describer or color profile for the printing device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple printheads are used to print the calibration target, then the printing coverage and efficiency are improved, but the uniformity of color reproduction deteriorates due to variations between individual printheads
Solution Approach 1:
The patent implements a feedback mechanism by measuring the actual printed values of control zones and comparing them against expected values. The system automatically detects deviations caused by printhead variations and generates corrective instructions to adjust ink application, thereby compensating for printhead non-uniformity and improving color reproduction consistency across multiple printheads.
Solution Approach 2:
The patent changes the parameters of ink application by dynamically adjusting the amount of ink applied by each printhead based on measured performance data. The system modifies printing parameters such as ink density and application volume to compensate for individual printhead variations, ensuring uniform color output across all printheads while maintaining high printing efficiency.
2Measurement precision
If control zones are added to the calibration target, then the detection of print anomalies is improved, but the complexity of the printing process increases
Solution Approach 1:
The patent segments the calibration target into distinct functional zones: control zones for monitoring printhead performance and colored zones for actual color reproduction. This segmentation allows the system to independently evaluate printhead uniformity through control zones before processing color calibration data, thereby improving anomaly detection without significantly complicating the overall printing workflow.
Solution Approach 2:
The patent performs preliminary evaluation of printhead performance by measuring control zones before processing the colored calibration zones. This preliminary action identifies and flags potential print anomalies early in the process, allowing the system to prevent erroneous color calibration while maintaining a straightforward sequential workflow that minimizes process complexity.
3Measurement precision
If measurements of all zones are processed to generate a describer, then the color calibration accuracy is improved, but the risk of propagating errors from defective printheads increases
Solution Approach 1:
The patent uses feedback from control zone measurements to validate the reliability of colored zone data before processing. The system compares measured values against expected ranges and automatically rejects or flags data from zones affected by defective printheads, thereby preventing error propagation while maintaining high color calibration accuracy through selective data processing.
Solution Approach 2:
The patent applies different processing quality standards to different zones based on their function. Control zones undergo strict validation against predefined tolerances to identify printhead defects, while colored zones are processed with adaptive quality control that depends on the validation results from control zones. This local quality approach ensures high calibration accuracy while minimizing the propagation of errors from defective areas.
Data Source
AI summary
A calibration target is printed by means of a printing device comprising a plurality of groups of printheads. The printheads of each group are fed with ink of the same color. The calibration target includes a plurality of colored zones that are intended to be subsequently processed. The printheads of each group further generate a series of control zones with the same nominal quantity of the corresponding ink. The control zones are free of overlapping between inks applied by different printheads. A parameter of each control zone is measured and the measured values of this parameter are compared to each other in order to assess whether the control zones exhibit print anomalies.