Matrix ink jet printer - has array of nozzles with discharge controlled by anode and cathode pairs
The matrix printing device is provided with arrays of nozzles, the discharge of droplets from any nozzle (3) being controlled by a carefully sized cathode (5) and anode (4) located adjacently. The nozzle is of predetermined size such that with fluid of a given viscosity, no discharge results when voltage is not applied across the anode and cathode. All anode and cathode pairs in the matrix arrangement are coupled to a voltage source over a switch. Combinational activation of the switch permits character matrix printing.