Inkjet status monitoring using meniscus measurement

摘要

Meniscus motion measurement techniques have been developed such that the jetting condition in a piezo inkjet head can be monitored. Acquired CCD camera images, where a strobe light from an LED (Light Emitting Diode) was synchronized by the jetting signal, were used to measure the meniscus motion. For efficient image processing of the acquired images, a straight line near the nozzle in the jetting direction was used for defining the ROI (Region of Interest). Then, the meniscus location can be identified from the discontinuity that exists in the pixel intensities along the ROI in the image. Finally, it was shown from the experimental results that the measured meniscus can predict jetting behavior without actual jetting.