Nozzle inspecting device in fluid discharge apparatus, fluid discharge apparatus, and nozzle inspection method

A nozzle inspection method in a fluid discharge apparatus including a discharge unit having nozzles which can discharge fluid to a target, an inspection electrode placed apart from the discharge unit with a gap therebetween, and an inspection unit which inspects presence of a defective nozzle on the basis of a detection value obtained by detecting a change of an intensity of an electric field when fluid is discharged by discharging the fluid to the inspection electrode from the discharge unit in a state in which an electric field is generated by applying a voltage between the discharge unit and the inspection electrode, the nozzle inspection method comprising:

• a detection step of detecting that the inspection unit is in a non-inspectable state, wherein the detection unit includes an electrode potential detection unit which detects a potential of the inspection electrode in a non-discharge state in which the fluid is not discharged before the inspection and a determination unit which determines that the inspection unit is in an inspectable state when the detection value detected by the electrode potential detection unit exceeds a predetermined threshold value and that the detection unit is in the non-inspectable state when the detection value is equal to or is less than the threshold value
• a gap adjustment step of adjusting the gap to come in a range in which the inspection unit is in the inspectable state by transferring either the discharge unit or the inspection electrode in a case in which it is detected such that the inspection unit is in the non-inspectable state;
• and
• an inspection step of discharging fluid to the inspection electrode from the discharge unit after the gap adjustment step and inspecting presence of the defective nozzle on the basis of the detection value obtained by detecting the change of the intensity of the electric field which is attributable to a discharge of the fluid.