Method for actuating an ink-jet print head

A method for actuating an inkjet print head (1), comprising at least one printing system (11) having a nozzle (8) on the side of an ink chamber (12) which faces a substrate to be imprinted, and which is delimited at least in areas, preferably in its area facing away from the print substrate, by a diaphragm (15) that is movable away from the ink chamber (12) by electrically actuating a piezo element (16) that is mechanically coupled to the diaphragm (15), so that ink is drawn into the ink chamber from an ink reservoir (14), and the diaphragm is movable toward or into the ink chamber so that an ink drop (24) is ejected from the ink chamber through the nozzle (8), wherein the printing system (11) made up of the ink chamber (12), diaphragm (15), piezo element (16), and the control circuit (18) thereof represents an oscillatable structure which, when actuated at high energy, is excited to oscillate at a natural frequency fres that exhibits resonance;

• i.e., the oscillation with the period Tres=1/fres undergoes little or no attenuation, and wherein the color intensity of a pixel to be printed is varied in that, for each pixel, a sequence of multiple ink drops (24) is ejectable in succession from the same nozzle (8) at a time interval of Tdrop=1/fdrop, characterized in that energy is only introduced into the printing system (11) via the actuation signal precisely when an ink drop (24) is actually to be ejected.