Patent ID: 7695086

Claim:
An ink jet printer, comprising: a passage unit comprising a nozzle, a pressure chamber, and an ink passage located between the nozzle and the pressure chamber; an actuator facing the pressure chamber, the actuator comprising a first electrode, a second electrode to which a reference potential can be applied, and a piezoelectric element located between the first electrode and the second electrode; and a pulse controller which applies a first voltage pulse to the first electrode such that the nozzle discharges an ink droplet, and a second voltage pulse to the first electrode such that the nozzle does not discharge the ink droplet, wherein a voltage change on a leading edge and/or a trailing edge of the second voltage pulse is greater than a voltage change on a leading edge and/or a trailing edge of the first voltage pulse; wherein the pulse controller comprises a voltage pulse outputting device, a first circuit located between the voltage pulse outputting device and the first electrode, and a second circuit located between the voltage pulse outputting device and the first electrode; wherein, when the pulse controller applies the first voltage pulse to the first electrode, a voltage pulse output by the voltage pulse outputting device is applied to the first electrode via the first circuit; wherein, when the pulse controller applies the second voltage pulse to the first electrode, the voltage pulse output by the voltage pulse outputting device is applied to the first electrode via the second circuit; and wherein the first circuit comprises a first resistor, and the second circuit comprises the first resistor and a second resistor connected in parallel with the first resistor.