Patent ID: 7387356
Filing Date: 2008-06-17
Classification: B41J

Abstract:
1. A droplet ejection apparatus comprising: a plurality of droplet ejection heads, each of the droplet ejection heads including: a driving circuit which drives the actuator of each droplet ejection head; a residual vibration detecting unit that detects a residual vibration of the diaphragm displaced by the actuator after the actuator has been driven by the driving circuit; a pulse generating unit that generates reference pulses; a computation unit that carries out a computation for the number of reference pulses generated by the pulse generating unit on the basis of the residual vibration of the diaphragm detected by the residual vibration detecting unit; a time measuring unit that measures a lapsed time since the actuator has been driven by the driving circuit; a head failure judging unit that judges a head failure in the droplet ejection heads on the basis of the computation result of the computation unit and the lapsed time measured by the time measuring unit; and a switching unit that switches a connection of the actuator from the driving circuit to the residual vibration detecting unit after carrying out the droplet ejection operation by driving the actuator.