Videojet Technologies Inc.

Dilip K Shrivastava

George W Arway

Frank Eremity

Andrew Earl Fickling

Mick Rybicki

Henry F George

A system and method of aligning a charge tunnel of a continuous inkjet printer with a drop generator and a catcher, wherein the charge tunnel passes through an outer wall of a charge tunnel unit, including adjusting a linear position of the charge tunnel unit, and adjusting a rotary position of the charge tunnel unit. The adjusting steps are performed to ensure that the charge tunnel is aligned with the drop generator and the catcher.

System for aligning a charge tunnel of an ink jet printer

According to 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 a deflection field created by the deflection electrode assembly. The deflection electrode assembly includes a high voltage electrode, a low voltage electrode, and an insulating housing which positions the high and low voltage electrodes in a predetermined spaced relationship along the ink drop stream. The insulating housing also has an internal resistor in electrical connection to the high voltage electrode and an external circuit. The insulating housing also contains an insulating member which supports the high voltage electrode as well as minimizes the possibility for arcing between the two electrodes.

High voltage arm assembly with integrated resistor, automatic high voltage deflection electrode locator, and special insulation

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 and a low voltage deflection electrode positioned on opposite sides of the ink drop stream. A dielectric insulating member is mounted on at least one of the deflection electrodes. The insulating member include a longitudinal opening which exposes the deflection electrode 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.

Ink jet printer deflection electrode assembly having a dielectric insulator

An continuous ink jet printer projects a stream of evenly spaced 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 field to control placement of said charged ink drops on a substrate. The printer may be used to print either single or multiple lines of print in a single stroke. A stroke consists of a single column from all lines and can have adjacent drops printed in alternating lines to reduce drop interaction. Each line of print in the stroke having N virtual print positions, at least some of which are being divided into pairs of adjacent positions. Each pair of adjacent positions has a first print position and a second print position. The printer includes a controller having a plurality of first and second look-up tables, each of which is associated with a different one of said pairs of adjacent print positions. Each of the look-up tables contains a plurality of charge values which correspond to the charge to be applied to a print drop in one of the first or second print positions, respectively, as a function of the charges of each of a predetermined number of drops that are proximate to the print drop in the drop stream. The adjacent drops may include a predetermined number of history drops that precede the print drop in the stream and a predetermined number of future drops that follow the print drop in the stream. The controller determines the charge to be applied to drops and produces a control signal responsive thereto by (1) retrieving a charge value from one of the first look-up tables if the drop is to be printed in one of the first print positions, or (2) retrieving a charge value from one of the second look-up tables if the drop is to be printed in one of the second print drop positions. A charging tunnel receives the control signal from the controller and charges the drops to the determined charges in response thereto.

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Bensenville, IL, United States of America

Dilip K Shrivastava