Patent classifications
B41J2/04516
LIQUID EJECTION HEAD AND LIQUID EJECTION APPARATUS
A liquid ejection head includes a nozzle, a pressure chamber that is capable of storing liquid and communicates with the nozzle, a volume of the pressure chamber being varied to eject the liquid from the nozzle, an actuator configured to vary the volume of the pressure chamber in response to a drive signal, and a drive circuit configured to generate the drive signal. The pressure chamber has one of states including: a steady state in which the volume is unchanged, an expanded state in which the volume is expanded, and a contracted state in which the volume is contracted. The drive signal includes first through fourth waveforms. A duration of the fourth waveform is shorter than a duration of the third waveform, and is at least 1 s or 0.5 times a half cycle of a main acoustic resonance frequency of the liquid in the pressure chamber.
Method for setting a drop shape in a printing process
A method for setting a drop shape in a printing process, including the steps of controlling (S101) a piezo element of a printing nozzle by a first voltage profile; detecting (S102) an electric current value averaged over the first voltage profile or a sound amplitude averaged over the first voltage profile; controlling (S103) the piezo element of the printing nozzle by a second voltage profile; detecting (S104) an electric current value averaged over the second voltage profile or a sound amplitude averaged over the second voltage profile; and selecting (S105) the voltage profile with the lower detected current value or the lower detected sound amplitude.