Patent ID: 6575551
Filing Date: 2003-06-10
Classification: B41J

Abstract:
An ink jet head for changing a volume of an ink passage with application of a driving voltage to an electrode, provided on side walls of the ink passage formed on a piezoelectric ceramic plate, and ejecting ink, filled in the interior thereof through a nozzle opening, comprising:a signal processing means for processing a piezoelectric signal generated on an electrode provided on each of the side walls of the ink passage; a selection means composed of a group of switches equipped for connecting the electrode, provided on each of the side walls of the ink passage, with any one of the driving voltage, a reference voltage and the signal processing means; and a control means for controlling the selection means, wherein the control means is provided with a judging means for judging a filling state of ink in the ink passage through controlling the selection means, driving one of the side walls adjacently disposed in said ink passage and detecting a piezoelectric signal generated on the other one of the side walls.