Patent ID: 8585175

Claim:
A nozzle state detecting apparatus for detecting states of a plurality of nozzles included in an ejecting head ejecting fluids from the nozzles by respectively driving a plurality of piezoelectric elements provided in the ejecting head and corresponding to the nozzles, the nozzle state detecting apparatus comprising: a voltage signal output unit that outputs a voltage signal for driving the piezoelectric elements; a plurality of first switches provided in association with the piezoelectric elements, and having input terminals connected to the voltage signal output unit and output terminals connected to electrodes of the respective piezoelectric elements to effect connection and disconnection between the input and output terminals; a plurality of second switches provided in association with the piezoelectric elements, and having input terminals connected to the electrodes of the respective piezoelectric elements to effect connection and disconnection between the input and output terminals; a plurality of voltage waveform detecting units provided in association with the piezoelectric elements and connected to the output terminals of the second switches to detect voltage waveforms of the respective piezoelectric elements via the second switches; and a nozzle state determining unit that, when detecting the states of the nozzles, controls the first switches and the second switches to set the first switches off and set the second switches on, and determines the states of the nozzles based on the respective voltage waveforms detected by the voltage waveform detecting units under the switch control.