Patent ID: 8613489

Claim:
An inkjet ejection apparatus comprising: an inkjet head which includes: a nozzle through which droplets of liquid are ejected to a recording medium; a liquid chamber which contains the liquid and is connected to the nozzle; and a piezoelectric actuator which applies pressure to the liquid in the liquid chamber when a drive signal is applied to the piezoelectric actuator; and a drive device which drives the inkjet head by supplying the drive signal so as to eject droplets of the liquid to selectively form dots of at least two different sizes on the recording medium, wherein the drive device includes: a waveform generating device which generates a standard drive waveform, the standard drive waveform containing, in one ejection cycle to form only one dot by the nozzle: a first ejection waveform group which includes one or more of ejection waveforms capable of causing the liquid to be ejected from the nozzle to form one dot of a maximum size on the recording medium; a first non-ejection waveform which is arranged after the first ejection waveform group by a first time interval from a start of a last one of the one or more of ejection waveforms of the first ejection waveform group until a start of the first non-ejection waveform, the first non-ejection waveform not causing the liquid to be ejected from the nozzle, the first non-ejection waveform being applied in order to suppress meniscus vibration after ejection; a second ejection waveform group which includes one or more of ejection waveforms capable of causing the liquid to be ejected from the nozzle to form at least a dot of a minimum size on the recording medium; and a second non-ejection waveform which is arranged after the second ejection waveform group by a second time interval from a start of a last one of the one or more of ejection waveforms of the second ejection waveform group until a start of the second non-ejection waveform, the second non-ejection waveform not causing the liquid to be ejected from the nozzle, the second non-ejection waveform being applied in order to suppress an occurrence of satellite after ejection; a waveform selecting device which selects from the standard drive waveform at least one of the ejection waveforms from one of the first and second ejection waveform groups in accordance with ejection data, the waveform selecting device further selecting the first non-ejection waveform when the selected at least one of the ejection waveforms belongs to the first ejection waveform group, the waveform selecting device further selecting the second non-ejection waveform when the selected at least one of the ejection waveforms belongs to the second ejection waveform group; and a drive signal generating device which generates the drive signal having the selected at least one of the ejection waveforms and the selected one of the first and second non-ejection waveforms.