Patent ID: 7770991
Filing Date: 2010-08-10
Classification: B41J

Abstract:
1. A method for controlling the print quality in an inkjet printer containing a substantially closed ink duct in which ink is situated, said duct being operationally connected to an electro-mechanical transducer, the method comprising: (a) actuating the electro-mechanical transducer with an actuation pulse according to a predetermined actuation setting in order to eject an ink drop from the duct nozzle, whereby a pressure wave is generated in the duct by the actuated pulse, the pressure wave causing a deformation of the electro-mechanical transducer which, in turn, generates an electrical signal, (b) analyzing the electrical signal for determining the presence of air bubbles in the duct. (c) repeating steps (a) and (b) for a plurality of actuation settings, (d) based on the analyses in steps (b) and (c), determining an actuation setting which separates the plurality of actuation settings into a first regime of actuation settings, for which the ejection of an ink drop is a stable process, and a second regime of actuation settings, for which the ejection of an ink drop is an unstable process, (e) selecting an actuation setting from the first regime, and (f) printing with the ink jet printer by actuating the electro-mechanical transducer with an actuation pulse according to the selected actuation setting.