Measurement of Frequency Characteristics of an Ink Circulation Supply System Considering System Constraints

Abstract

The application fields of inkjet printers have expanded, leading to a wider variety of inks and making ink compatibility a critical issue. To address this, devices equipped with ink circulation systems, designed to prevent ink drying and sedimentation, are increasingly adopted. This study investigates a method for measuring the frequency characteristics of a MIMO (multi-input multi-output) ink circulation system. The system controls pressure at multiple points using pumps and features cross-coupling between controlled variables. Importantly, it requires active control to function, presenting unique constraints. A frequency-response measurement method that accounts for these constraints is proposed, and its effectiveness is validated through application to a real-world system.