US Patent 7651190 Inkjet recording apparatus

A recording head includes a main body and electrodes. The main body has a nozzle plate. The electrodes are arranged on the front surface of the nozzle plate. A current sensor is connected to the electrodes through connection terminals, and measures a current value flowing in the respective electrodes. The electrodes correspond respectively to the colors of inks to be discharged. Each of the electrodes is separated from the edge of the nozzle hole by 1 μm to 5 μm. The nozzle plate has a water repellent layer on the front surface. The electrodes connect a plurality of nozzle holes in series.