US Patent 7708384 Printing apparatus

A printing apparatus which discharges an electroconductive ink includes an ink transporting head having a head main body in which a discharge port and an individual ink channel are formed, an individual electrode which is formed on a surface defining the individual ink channel, and an insulating layer which covers the individual electrode, and a transfer drum which is rotatably supported. When a drive voltage is applied to the individual electrode, since a liquid repellent property of the insulating layer is declined due to an electrowetting phenomenon, the ink is discharged from the discharge port. Furthermore, a distance between the discharge port and the transfer drum is less than a diameter of a liquid droplet equivalent to a liquid discharged at a time from the discharge port. Accordingly, it is possible to provide a printing apparatus having a simple structure, and of which a size can be reduced easily.