Patent ID: 7195327

Claim:
A droplet ejection apparatus comprising: a drive signal generator for generating a set of drive signals including a plurality of drive pulses; a drive pulse selector for selecting a set of drive pulses in accordance with a print datum of each pixel; and a head for ejecting a droplet from a nozzle corresponding to a channel, by changing a volume of the channel in accordance with the selected set of drive pulses; wherein the drive signal includes a micro-vibration pulse as at least one of the drive pulses to generate a micro-vibration of a meniscus in the nozzle in such a degree that the droplet is not ejected, said micro-vibration pulse comprising at least one rectangular wave, including at least one rectangular wave which has a pulse width of (2n) AL, where AL is ½ of an acoustic resonance period of the channel, and n is an integer not smaller than 1.