Ink jet printer and deflector plate therefor

Abstract

A combined deflection electrode and phase sensor electrode for a deflection type ink jet printer is made up of a ceramic support plate a conductive layer acting as the deflection electrode, layers of insulator covering the conductive layer and a patch of conductive material on the layers of insulator to provide a phase sensor electrode (Alternative constructions are also disclosed). A time of flight sensor electrode may also be provided in the same way. The layers of insulator prevent the sensor electrodes from being electrically connected, by splashes of conductive ink, to the deflection electrode provided by the conductive layer The sensor electrodes can have a larger sensing area than separately provided electrodes, allowing them to be further from the ink jet and thereby easing alignment requirements. Additionally, the flight path of the ink jet from the nozzle to the gutter is shortened by placing the sensor electrodes within the length of the deflection electrode. The combined electrode design may be applied to single jet printers, double jet printers and printers having an array of jets (e.g. for printing graphics).