PURPOSE: To lower the cost of a recorder by a method wherein a charged electrode and an ink drop attaching body are built on the surface of the same insulation substrate and an introduced current generated with the flying and attachment of charged ink drops is detected to determine whether injection is done at a high accuracy.
CONSTITUTION: A voltage pulse is applied to a piezo-eletric element 12 of a head 10 to be converted into a pressure pulse which is transmitted to a nozzle 11 and an ink is extruded from the nozzle 11 to fly in drops 13. At this point, several ten W several hundred V is applied between the nozzle 11 and an electrode 14 of an electrode plate 18 in which an ink drop attaching body 15 is connected to a detection circuit 16 and additionally, the charged electrode 14 and the body 15 are built on the same insulation substrate 17 to have ink in charged ink drops flying and as it approaches the body 15, an electric charge is induced in the body 15 opposite in the polarity to the charge of the ink drops 13 and amplified to the positive voltage about 100 times with the circuit 16 to be compared with the reference voltage by a comparator therein 16, which outputs a detection signal when it exceeds the reference voltage. Thus, the injection of ink drops, namely, possible nozzle clogging can be detected.
SATOU KAZUHIKO
NAKAJIMA JIYUNZOU
Next Patent: INKJET RECORDER