Ink Jet Nozzle Detection via Image Collation
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Solution Overview
Problem
Existing image inspection techniques for ink jet printing systems fail to accurately specify defective nozzles during continuous printing, leading to reduced productivity and potential degradation of image quality due to excessive correction, and are unable to effectively detect and correct streak defects caused by nozzle issues.
Innovation Solution
An image inspection device and method that acquires and analyzes data from both defective nozzle detection patterns and printed images, utilizing a history of detection results to accurately specify defective nozzles and perform targeted image quality corrections, thereby preventing unnecessary correction processes and improving defect detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If defective nozzle detection is performed using ladder pattern printing, then defective nozzle position can be identified, but productivity decreases due to time required for detection and correction processes
Solution Approach 1:
The system performs preliminary detection of defective nozzles by incorporating ladder patterns in the printed matter, allowing identification before the defective nozzles cause widespread quality issues. This enables proactive correction while maintaining continuous printing operations.
Solution Approach 2:
The system establishes a feedback loop where detection results from ladder pattern analysis are fed back to correct the defective nozzles in real-time during continuous printing. This feedback mechanism allows the system to adapt and correct issues dynamically without stopping production.
2Manufacturing precision
If image quality correction is performed for detected defective nozzles, then image quality improves, but unnecessary corrections may degrade overall image quality and increase processing time
Solution Approach 1:
The system uses feedback from streak defect detection to verify whether correction is actually needed. By continuously monitoring the printed matter for streak defects and comparing them with detection results, the system can confirm whether a nozzle is truly defective before applying correction, avoiding unnecessary corrections that would degrade image quality.
Solution Approach 2:
The system replaces manual inspection and correction processes with automated image analysis algorithms that can detect streak defects and determine correction necessity. This substitution of mechanical inspection with optical and computational methods enables more precise and efficient decision-making about corrections.
3Measurement precision
If streak defect detection is performed on printed matter, then defect identification accuracy improves, but the system cannot reliably specify which nozzle caused the defect
Solution Approach 1:
The system merges two detection approaches: ladder pattern analysis for nozzle-level identification and streak defect detection for quality verification. By combining these methods, the system achieves both the ability to specify defective nozzles and the accuracy to confirm actual defects, resolving the information loss problem.
Solution Approach 2:
The ladder pattern serves as an intermediary element that bridges the gap between nozzle operation and visible defects. It provides a direct link between the physical nozzle state and the visual output, enabling the system to trace streak defects back to specific nozzles with high reliability.
Data Source
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AI summary
An image inspection device analyzes data of a first read image obtained by reading a defective nozzle detection pattern which is recorded in a first region of a recording medium by a single pass ink jet printing apparatus to detect a defective nozzle of a line-type ink jet head used to record the defective nozzle detection pattern and stores a history of the detection result of the defective nozzle in a history information storage unit. The image inspection device analyzes data of a second read image of a printed image recorded in a second region of the recording medium to detect an image defect of the printed image and collates information about the detected image defect with history information stored in the history information storage unit to specify a defective nozzle causing the image defect.