Patent ID: 7328962

Claim:
A droplet ejection apparatus having a driving circuit and a plurality of droplet ejection heads, each of the droplet ejection heads including a cavity filled with a liquid, a nozzle communicated with the cavity, an actuator driven by the driving circuit, and a diaphragm displaced by the actuator, the droplet ejection head ejecting the liquid within the cavity through the nozzle in the form of droplets by driving the actuator with the driving circuit, the droplet ejection apparatus comprising: an ejection failure detecting and recovery processing determining unit which detects a residual vibration of the diaphragm at least when the apparatus is powered on, and then detects an ejection failure of the droplet ejection heads on the basis of a vibration pattern of the detected residual vibration of the diaphragm and determines recovery processing for eliminating the ejection failure; and a recovery unit which carries out the recovery processing determined by the ejection failure detecting and recovery processing determining unit; wherein: the ejection failure detecting and recovery processing determining unit identifies a cause of the ejection failure of the droplet ejection heads on the basis of the vibration pattern of the residual vibration of the diaphragm; the vibration pattern of the residual vibration of the diaphragm includes a cycle of the residual vibration; and the ejection failure detecting and recovery processing determining unit judges that: an air bubble has intruded into the cavity in the case where the cycle of the residual vibration of the diaphragm is shorter than a predetermined range of cycle; the liquid in the vicinity of the nozzle has thickened due to drying in the case where the cycle of the residual vibration of the diaphragm is longer than a predetermined threshold; and paper dust is adhering in the vicinity of the outlet of the nozzle in the case where the cycle of the residual vibration of the diaphragm is longer than the predetermined range of cycle and shorter than the predetermined threshold.