Methods of ejecting droplets from an array of pulsed droplet ejectors

Claim 1

A method of ejecting droplets from an array (A) of pulsed droplet ejectors with minimum cross talk, said array comprising an array of channels (15) for containing fluid (13), and a transducer (1) for each said channel (15) in a position such that when said transducer (1) is energized by application of a drive pulse, said transducer (1) applies pressure to said channel (15) to eject a fluid droplet (20) therefrom, said method being characterised in that said drive pulse has a pulse width selected to minimize cross talk between said channels (15).

Claim 2

A method of ejecting droplets from an array (A) of pulsed droplet ejectors with minimum cross talk, said array comprising an array of channels (15) for containing fluid (13), and a transducer (1) for each said channel (15) in a position such that when said transducer (1) is energized by application of a drive pulse, said transducer (1) applies pressure to said channel (15) to eject a fluid droplet (20) therefrom, said method being characterised in that said drive pulse has a pulse width selected to minimize cross talk between said channels (15).

Claim 4

A method of operating an array (A) of pulsed droplet ejectors (E), characterized by the steps of (a) determining the velocity of ink droplets ejected from a first selected ejector (E) in the ejector array (A) when said first ejector is operated alone at a first preset drive pulse width; (b) determining the velocity of ink droplets ejected from said first selected ejector (E) when at least one adjacent ejector (E) is operated at the same time as said first ejector, said ejectors (E) being driven by a drive pulse of the same width as said first preset drive pulse width; (c) determining the difference in droplet velocities obtained from steps (a) and (b); (d) selecting a drive pulse having a different pulse width than previously used in steps (a)-(c) and repeating steps (a)-(c) using said different pulse width; (e) repeating steps (a)-(d) a sufficient number of times until a drive pulse width can be selected that provides acceptable image quality both when said first ejector (E) is operated alone and when said first ejector (E) is operated at the same time as adjacent ejectors (E); and (f) operating an ejector array (A) using a drive pulse having the drive pulse width selected in step (e).

Claim 5

A method of operating an array (A) of pulsed droplet ejectors (E), characterized by the steps of (a) determining the velocity of ink droplets ejected from a first selected ejector (E) in the ejector array (A) when said first ejector is operated alone at a first preset drive pulse width; (b) determining the velocity of ink droplets ejected from said first selected ejector (E) when at least one adjacent ejector (E) is operated at the same time as said first ejector, said ejectors (E) being driven by a drive pulse of the same width as said first preset drive pulse width; (c) determining the difference in droplet velocities obtained from steps (a) and (b); (d) selecting a drive pulse having a different pulse width than previously used in steps (a)-(c) and repeating steps (a)-(c) using said different pulse width; (e) repeating steps (a)-(d) a sufficient number of times until a drive pulse width can be selected that provides acceptable image quality both when said first ejector (E) is operated alone and when said first ejector (E) is operated at the same time as adjacent ejectors (E); and (f) operating an ejector array (A) using a drive pulse having the drive pulse width selected in step (e).