Xerox Corporation

Kenneth H Fischbeck

Allen T Wright

Richard H Vernon

Lee L Bain

Marcus M Schnarr

Curt R Raschke

Edward Forest

Joel W Grover

Linda T Creagh

Stig-Goran Larsson

S Bertil Sultan

Demetris E Paraskevopoulos

Demetris F Paraskevopoulos

Ganesh L Harpavat

A single piezoelectric transducer is used to drive an array of drop-on-demand ink jet ejectors. This is accomplished by utilizing a plurality of electrodes which divide the piezoelectric transducer into discrete, deformable sections, each section corresponding to an ejector.

Shear mode transducer for drop-on-demand liquid ejector

A pressure pulse liquid droplet ejecting method wherein an induced current within a liquid causes rapid formation of a vapor. The vapor expansion forces droplet ejection. In a preferred method, the induced current is focused by an intermediate dielectric layer placed in the liquid.

Electrothermic ink jet

A circuit for use in an ink jet printer in which the carriage motion either approximates a sinusoidal vibratory pattern, or which has any variable velocity pattern that reliably repeats from cycle to cycle. It is further assumed that the printer will print in both directions of the carriage, and that the flight time of the ink drop from jet to paper is constant. A counter starts at a value corresponding to the flight time of the ink drop, and then measures the time of the carriage over a predetermined distance. The difference is the required delay. A second delay counter uses this value to produce a time delay prior to ejecting the ink drop. Since, in an actual ink jet printer, several drops will be in transit at the same time, the circuit is provided with a plurality of phases or channels which operate concurrently.

Circuitry for correcting dot placement for oscillating carriage ink jet

Horizontal interlacing is used in an oscillating bar drop-on-demand ink jet printer to improve image quality, particularly in solid black areas. The disclosed system provides a method for printing that allows the image-receiving surface to be forwarded continuously, reducing the requirement for stepwise operation.

Ink jet printing using horizontal interlacing

A pressure pulse drop ejector which incorporates a check valve at both ends of a tubular electromechanical transducer. The transducer is used both to radially squeeze ink through a check valve to an orifice and then by elongating, expressing a droplet from the orifice. The check valves provide the means necessary for preventing air ingestion into the drop ejector.

Ink jet ejector utilizing check valves to prevent air ingestion

A check valve for a drop-on-demand pressure pulse ejector for preventing pressure pulse loss to the liquid supply system. The check valve is made by electrodeposition onto the surface of a substrate.

Electrodeposition method for check valve

A method of minimizing crosstalk between transducer driven pulse liquid droplet ejectors in ejector arrays. An array mounted on a scanning carriage and having nozzles inclined to the direction of relative motion between the carriage and the print-receiving member is designed such that adjacent nozzles are not fired simultaneously. Similarly, an oscillating bar pulse ejector array is designed such that adjacent nozzles are not fired simultaneously.

Configurational reduction of pulse ejector crosstalk

The invention relates to an oscillating bar drop-on demand ink jet printer where printing occurs while the bar is moving bidirectionally over a transversely moving record-receiving surface. Specifically, the invention relates to a method of increasing the effective print speed of such a printer by electrostatically compensating for the inherent velocity variation of the oscillating bar as it oscillates.

Bidirectional ink jet printing

Electrostatic deflection is used in an oscillating bar drop-on-demand ink jet printer to compensate for about one half of the droplet displacement caused by bar velocity. The disclosed system provides a method for printing that is not sensitive to variations in ink droplet ejection velocity.

Ink jet printing using electrostatic deflection

Electrostatic deflection is used to provide multiline printing from a single pass in an oscillating bar ink jet printer.

Method for ink jet printing where the print rate is increased by

An oscillating bar drop-on-demand ink jet printer is used to print on a continuously moving record-receiving surface. The record-receiving surface moves in a direction orthogonal to the direction of oscillation of the oscillating bar, the resultant trace being a sine wave. Electrostatic deflection is utilized to square off the sine wave to a preferred rectangular trace.

Ink jet printing

Electrostatic deflection is used to correct velocity induced droplet placement errors in an oscillating bar ink jet printer.

Method for ink jet printing

A method and apparatus for marking wherein an array of marking elements is used to mark on a continuously moving mark-receiving surface. In order to provide a rectangular grid in an efficient manner, the array is oscillated both perpendicular and parallel to the direction of movement of the mark-receiving surface.

Method and apparatus for oscillating an array of marking elements

A coincidence ink jet principle is disclosed wherein each ink jet has two inlet passages communicated to an outlet orifice. Each inlet passage is communicated to a respective transducer chamber. The fluid displacement and fluid velocity effected by a pressure pulse generated by each transducer chamber in a respective inlet passage is insufficient to express a droplet from the orifice. However, the combined fluid displacement and fluid velocity, which is the result of the pressure pulses generated by the transducers being coincident at the orifice, will result in a droplet being expressed from the orifice. In one system disclosed utilizing the above described principle, each inlet passage of a jet is communicated to a respective transducer and each transducer is connected to a respective electronic driver. In this system, the number of electronic drivers and transducer chambers are substantially less than the number of ink jets. These transducer chambers are time shared for expressing an ink droplet. Actuation of the two transducer chambers communicated to a particular jet, in such a manner that the pressure pulses generated by the respective transducers coincide at the orifice, will effect expression of a droplet therefrom. In another system disclosed utilizing the above described principle, a master transducer chamber is communicated to a separate respective droplet expression transducer chamber and each droplet expression transducer chamber is connected to a respective electronic driver. In this system, the master transducer chamber is actuated to create at each orifice a pressure pulse which is below the threshold pressure pulse for expressing an ink droplet therefrom. Actuation of any of the droplet expression transducer chambers to generate a pressure pulse which coincides at a particular orifice with the pressure pulse generated by the master transducer, will bring the resultant pressure pulse at the orifice above threshold to effect expression of the droplet from a particular orifice.

Coincidence fluid displacement and velocity expression of droplet

An improved suspension for an axially oscillating bar. The suspension is a trifurcated spring, the bar being attached to the central section of the spring. The spring may be mounted to act as a multiple cantilever spring. Preferably, two matching springs are used to suspend the bar.

Growing community of inventors

Dallas, TX, United States of America

Kenneth H Fischbeck