Patent ID: 7341325

Claim:
A droplet ejection apparatus comprising: a plurality of droplet ejection heads, each of the droplet ejection heads including: a diaphragm; an actuator which displaces the diaphragm; a cavity filled with a liquid, an internal pressure of the cavity being increased and decreased in response to displacement of the diaphragm; and a nozzle communicated with the cavity, through which the liquid is ejected in the form of droplets in response to the increase and decrease of the internal pressure of the cavity; a driving circuit which drives the actuator of each droplet ejection head; a pulse generating unit for generating reference pulses; a counter for counting a number of reference pulses generated for a predetermined time period; an ejection failure detecting unit for detecting an ejection failure of the droplets on the basis of a count value of the counter counted for the predetermined time period; and a switching unit for switching a connection of the actuator from the driving circuit to the ejection failure detecting unit after carrying out a droplet ejection operation by driving the actuator; wherein the ejection failure detecting unit detects presence or absence of the ejection failure by comparing a normal count range of the reference pulses when a droplet is normally ejected by the driving of the actuator with a count value of the counter counted for the predetermined time period.