Inkjet Nozzle Inspection Control for Stable Droplet Landing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing apparatuses face issues with ink droplet adhesion instability and image quality degradation due to varying ejection speeds and unstable flying states, leading to poor image definition and reproducibility, especially in large-sized prints.
Innovation Solution
A printing apparatus equipped with a detection unit to assess the ejecting condition of ink droplets, a recovery unit to correct nozzle conditions, and a control unit to selectively perform inspections based on nozzle states, ensuring accurate ink landing on the printing medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the ejection speed of ink droplets changes, then the adhesion position of ink droplets varies between forward and backward directions, but the image definition and reproducibility of thin lines deteriorate
Solution Approach 1:
The system performs preliminary detection of the ejecting condition using a detection unit before actual printing. Based on the detected ejection speed and flying state, the control unit pre-adjusts the ejection timing to compensate for expected position deviations, ensuring accurate adhesion positions are achieved before printing begins
Solution Approach 2:
The detection unit continuously monitors the ejecting condition of ink droplets, providing real-time feedback to the control unit. The control unit adjusts the ejection timing based on this feedback, creating a closed-loop control system that maintains accurate image definition and reproducibility despite variations in ejection speed
2Reliability
If the flying state of ink droplets becomes unstable, then the landing on paper surface is not accurately performed, but the known type fails to detect image degradation
Solution Approach 1:
The detection unit is positioned to detect the flying state of ink droplets before they land on the paper surface. This preliminary detection allows the system to identify unstable flying states and potential image degradation issues before actual printing occurs, enabling preventive adjustments
Solution Approach 2:
The detection unit acts as an intermediary between the printing head and the paper surface, monitoring the flying state of ink droplets in the air. This intermediary detection capability allows the system to measure and detect image degradation potential without requiring actual paper printing, solving the difficulty of detecting flying state instability
3Measurement precision
If inspection of all nozzles is performed continuously, then accurate detection of ejecting condition is achieved, but printing productivity is reduced due to frequent inspections
Solution Approach 1:
The control unit selectively determines which nozzles require inspection based on their individual states. Instead of inspecting all nozzles continuously, only nozzles that need inspection are selected, performing partial inspection action that maintains detection accuracy while minimizing interruptions to printing productivity
Solution Approach 2:
The system performs preliminary assessment of nozzle states to determine which nozzles require inspection. This preliminary action allows the control unit to pre-identify nozzles that need attention and schedule their inspection during appropriate intervals, balancing detection accuracy with productivity requirements
Data Source
AI summary
A printing apparatus includes a detection unit that is arranged to face an ejecting surface on which a plurality of nozzles of a printing head that ejects liquid droplets are arrayed, and detects an ejecting condition of the liquid droplets; a recovery unit that recovers an ejecting condition of nozzles of the printing head; and a control unit that determines whether to perform or skip inspection of the ejecting condition by the detection unit based on a state of each of the nozzles of the printing head, and controls a nozzle for which the inspection of the ejecting condition is determined to be skipped so as to perform the inspection of the ejecting condition by the detection unit after the recovery unit recovers the ejecting condition of the nozzle.