Patent ID: 7604313

Claim:
An ink-droplet ejecting apparatus comprising: a plurality of ink passages each of which comprises a pressure chamber filled with ink; a plurality of actuators each of which is configured to change, upon receiving a drive signal, an inner volume of one of the pressure chambers to generate a pressure wave in the ink in the pressure chamber which wave propagates along a corresponding one of the ink passages to eject a droplet of the ink onto a recording medium; and a control unit which is connected to the plurality of actuators and is configured to supply the drive signal to the actuators, such that the drive signal comprises a waveform which is for forming a single dot on the recording medium and comprises (i) a main pulse which ejects the droplet, (ii) a preceding pulse outputted before the main pulse, and (iii) a stabilizing pulse outputted after the main pulse, a pulse width of the main pulse being not coincident with a one-way propagation time AL which is a time taken by the pressure wave to propagate one way along the ink passage, the preceding pulse being outputted in a manner not to eject the droplet, and the stabilizing pulse being outputted in a manner to pull back a part of the droplet as beginning to be ejected by the main pulse, wherein each of the preceding pulse, the main pulse, and the stabilizing pulse increases the inner volume of the pressure chamber at a start of each pulse and decreases the inner volume at a terminal end of each pulse.