US Patent No. 9,579,889

METHOD OF EJECTING INK DROPLETS HAVING VARIABLE DROPLET VOLUMES


Patent No. 9,579,889
Issue Date February 28, 2017
Title Method Of Ejecting Ink Droplets Having Variable Droplet Volumes
Inventorship Vincent Patrick Lawlor, Dublin (IE)
Gregory John McAvoy, Dublin (IE)
Emma Rose Kerr, Dublin (IE)
Misty Bagnat, Dublin (IE)
Assignee Memjet Technology Limited, (IE)

Claim of US Patent No. 9,579,889

1. A method of ejecting an ink droplet from an inkjet nozzle device having an actuator and a meniscus pinned across a nozzle
opening, said method comprising the steps of:
delivering a sub-ejection pulse to the actuator for perturbing the meniscus from a quiescent state; and
subsequently delivering an ejection pulse to the actuator at an instant when the meniscus is perturbed from its quiescent
state, the ejection pulse ejecting the ink droplet from the nozzle opening,
wherein:
a time period between a trailing edge of the sub-ejection pulse and a leading edge of the ejection pulse controls a droplet
volume of the ejected ink droplet;

a relatively shorter time period produces a relatively larger droplet volume; and
a relatively longer time period produces a relatively smaller droplet volume.