Patent ID: 8628176

Claim:
A method of driving an electromechanical converter of a print head of a continuous inkjet printer, the electromechanical converter being arranged to break up a continuous stream of ink into a plurality of drops, the method comprising: providing an ink that does not have a turning point in a characteristic of a gradient of a property at least indicative of a break up point of the continuous stream of the ink versus a modulation voltage; determining a characteristic of a gradient of a property at least indicative of a break up point of the continuous stream of the ink versus a modulation voltage; determining a modulation voltage to drive the electromechanical converter, a property of the modulation voltage being controlled to take into account movement of a break up point of the continuous stream of the ink, and to ensure that in the characteristic of the gradient of a property at least indicative of the break up point of the continuous stream of the ink versus the modulation voltage has a predetermined non-zero value, wherein the property at least indicative of the break up point of the continuous stream of the ink is one of a group comprising: a break up point; a break up length; a break up time; and a phase angle between a break up point and a signal used to give drops of the ink a charge; and driving the electromechanical converter at the determined modulation voltage, wherein the method is not dependent on the identification of a turning point in the characteristic of a gradient of a property at least indicative of a break up point of the continuous stream of the ink versus a modulation voltage.