Abstract: An ink jet printer utilizing a smooth surfaced transfer drum is shown as an illustrative embodiment of the invention. The transfer drum and the print head assembly are mounted between a pair of side plates (only one of which is shown in the drawing). A print head assembly, which comprises a number of ink jet nozzles, is also mounted between the side plates. The print head assembly is spaced apart from the drum and the nozzles thereof are spaced at equal distances along a line which is parallel to the axis of the drum. The print head assembly is movable in fine steps from left to right so that on successive rotations of the drum each nozzle is directed to a new track of a succession of tracks. After all tracks of the transfer drum have been served by a nozzle assembly, a printing medium, e.g.

Abstract: The illustrated ink jet (19) includes a chamber (22) containing a quantity of ink (54) discharged through a nozzle orifice (28) in the form of droplets (84). The ink is discharged in response to movement of an actuator positioned over a chamber (22) opening. The actuator (50) includes a piezoceramic plate (60), the surfaces of which are covered by electrodes (62, 64). Soldered to the electrode (62) is a bending plate (56) which is secured by adhesive (58) to a flexible sheet of insulating material (52). Control signals are fed through conductors (72, 59) to the electrodes (62, 64).