INK JET PRINTER DEFLECTION ELECTRODE ASSEMBLY HAVING A DIELECTRIC INSULATOR

摘要

According to certain aspects of an embodiment of the present invention, a deflection electrode assembly is provided for use in a continuous ink jet printer of the type which projects a stream of ink drops toward a substrate and controls placement of the ink drops on the substrate by selectively charging the individual ink drops and passing the charged ink drops through an electric (deflection) field created by the deflection electrode assembly. The deflection electrode assembly includes a high voltage deflection electrode (56) and a low voltage deflection electrode (44) positioned on opposite sides of the ink drop stream. A dielectric insulating member (46) is mounted on at least one of the deflection electrodes. The insulating member include a longitudinal opening (66) which exposes the deflection electrode (42) along the path of the ink jet stream, thereby virtually eliminating the tendency for accumulated ink to decrease the strength of the deflection field. The insulating member extends inwardly and underlies the bottom face of the deflection electrode along at least its front and side edges. Providing insulation along the front and side edges of the deflection electrode reduces arcing between the deflection electrodes. Providing the longitudinal opening in the insulating member reduces the field distortion effects of micro-satellite ink drops that would otherwise accumulate on the insulating member.