Patent ID: 7571998

Claim:
A printing method for an inkjet printer containing a substantially closed ink duct provided with a nozzle, said duct being operationally connected to an electro-mechanical transducer, which is configured to be actuated with an actuation pulse having an actuation frequency and an actuation amplitude for generating a pressure wave in the duct, the pressure wave having a pressure frequency and a pressure amplitude, said method comprising the steps of: a) determining a presence of an air bubble in the ink duct, b) determining a size of the air bubble, c) determining an equilibrium frequency associated with the air bubble in equilibrium with said size the air bubble, d) actuating the transducer with at least one actuation pulse, having a frequency which is lower than the frequency determined in step c) and having an amplitude which is so large that ink drops are ejected from the nozzle for eliminating the air bubble.