Selective Inkjet Defect Detection via Image Sensor

The patent applies local quality by differentiating treatment for different inkjets based on their individual failure probabilities. Instead of uniform testing of all inkjets, the system identifies specific inkjets with higher failure probabilities (through monitoring drop characteristics, ejection frequency, and operational history) and targets those for testing. This localized approach ensures reliable defect detection for at-risk inkjets while avoiding unnecessary testing of reliable inkjets, thereby reducing waste of system resources and ink.

The patent utilizes parameter changes by dynamically adjusting testing frequency and scope based on monitored parameters such as drop mass, drop velocity, directionality, and ejection frequency. When parameters indicate an inkjet is approaching failure thresholds, testing frequency increases. When parameters show stable performance, testing frequency decreases. This adaptive parameter adjustment maintains detection reliability while optimizing resource consumption.

The patent implements local quality by assigning different testing frequencies to different inkjets based on their individual failure probabilities. Inkjets with higher failure probabilities receive more frequent testing, while those with lower failure probabilities are tested less frequently. This differentiated approach maintains detection consistency for at-risk components while improving overall testing efficiency by avoiding redundant testing of reliable inkjets.

The patent applies dynamics by making the testing schedule adaptive rather than static. The system continuously monitors inkjet performance parameters and dynamically adjusts testing frequencies based on real-time conditions. When an inkjet's performance deteriorates, testing frequency increases automatically. When performance is stable, testing frequency decreases. This dynamic adjustment maintains detection consistency where needed while optimizing productivity overall.

The patent applies parameter changes by using monitored parameters (drop characteristics, ejection frequency, operational history) to predict failure probabilities. These parameters enable the system to adjust testing timing strategically - performing tests when parameters indicate approaching failure thresholds rather than at fixed frequent intervals. This maintains inkjet reliability through timely detection while reducing unnecessary testing time and resources.

The patent implements preliminary action by using performance parameter monitoring to predict potential failures before they occur. The system identifies inkjets that are likely to fail based on trends in drop mass, velocity, and ejection frequency, and schedules testing in advance for these at-risk inkjets. This proactive approach ensures reliability is maintained through early detection while avoiding the time waste of reactive testing after failures occur.