CONTROLLING METHOD FOR JETTING OF INK DROPLET

摘要

PURPOSE:To stabilize the flying of ink droplets by impressing on an electrostrictive strain element a voltage having a polarity reverse to the one at the time of ink jetting just before jetting of the ink droplets and thereby drawing the ink around a nozzle into the nozzle prior to the jetting of the ink droplets. CONSTITUTION:A pulse generating circuit 14 is connected to a one-shot circuit 16 through a delay circuit 15 and switching means 10-13 controlling the impression of voltage on the electrostrictive strain element 4 and the polarity of the impressed voltage are provided. The means 10 and 11 are transistors of NPN type, while 12 and 13 are transistors of PNP type. By a driving pulse P1 the transistors 10 and 11 turn conductive and driving supply voltage Vcc is impressed on the electrostrictive strain element 4 in the reverse direction to that when the ink droplets are jetted. When a driving pulse P2 is supplied from the circuit 16 at the time T, the transistors 12 and 13 turn conductive and the driving supply voltage Vcc is impressed on the electrostrictive strain element 4 in the direction of the jetting of the ink droplets.