Xerox Corporation

Dale R Ims

Michael P O'Horo

Gary Alan Kneezel

Ivan Rezanka

Narayan V Deshpande

Donald J Drake

William G Hawkins

Armand P Neukermans

Cathie J Burke

Roger Guy Markham

Juan J Becerra

Joseph F Stephany

Joseph J Wysocki

Thomas A Tellier

Lesley P Dudek

Michael C Ferringer

David Allen Mantell

Steven Jay Harrington

John Richard Andrews

Yonglin Xie

Bing R Hsieh

John F Knapp

Roger N Ciccarelli

Robert J Gruber

Ian D Morrison

Michael Robert Campanelli

Kurt B Gundlach

William M Schwarz

David G Anderson

Richard B Lewis

Steven B Bolte

Brian S Hilton

Min-Hong Fu

William R Burger

Thomas E Watrobski

Herman A Hermanson

Richard V LaDonna

Alan D Raisanen

Mark D Tracy

Eduardo Mariano Freire

Scott Charles Warner

Yungran Choi

Scott N Seabridge

W Conrad Richards

Vaughan Louis Dewar

Narayan V Desphande

Narayan Deshpende

A method and apparatus are providing for extending the drop volume control of a thermal ink jet print head. The print head has a plurality of drop ejectors, each of the plurality of drop ejectors has a heating element actuatable in response to input signals to eject an ink droplet from the print head. The method includes the steps of applying a plurality of print signals to the print head, the plurality of print signals corresponding to an image for the ink jet assembly to create, applying at least one pulse signal to the print head, and sequentially using the at least one pulse signal and the plurality of print signals to activate the heating elements so that the change in current remains small. In addition, the apparatus has a print data storage element that receives print data from a printer controller, a pulse data delay element that receives pulse data from either a print head controller or a previous drop ejector and sends the pulse data to a next drop ejector after a predetermined delay, a heating element and a checksum element that, when the data storage element contains print data, and the pulse data delay element contains pulse data, activates the heating element according to the print data and the pulse data.

Method and apparatus for thermal ink jet drop volume control using variable prepulses

A method and apparatus for controlling the volume of ink droplets ejected from printhead nozzles over a larger printhead operating temperature range. Each nucleating electrical pulse applied to the heating elements in the printhead to eject an ink droplet is preceded by a plurality of non-nucleating pre-pulses. Based upon the printhead temperature sensed, a controller selects the pre-pulse width and time width between pre-pulses from a look-up table.

Thermal ink jet printhead extended droplet volume control

The new heater element design has a pit layer which protects the overglaze passivation layer, PSG step region, portions of the Ta layer and dielectric isolation layer and junctions or regions susceptible to the cavitational pressures. Further, the inner walls of the pit layer define the effective heater area and the dopant lines define the actual heater area. In alternative embodiments, the dopant lines define the actual and effective heater areas, and an inner wall and a dopant line define the actual and effective heater areas. Further, when the new heater element designs are incorporated into printheads having full pit channel geometry and open pit channel geometry, the operating lifetime of the printhead is extended because the added protection of the pit layer prevents: 1) passivation damage and cavitational damages of the heater elements; and 2) degradation of heater robustness, hot spot formations and heater failures well into the 10,pulse range. The printhead incorporating the new heater element design can be incorporated into drop-on-demand printing systems of a carriage type or a full width type.

Thermal ink jet heater design

The systems and methods of this invention allows for an electrical contact structure of the drop ejecting transducer in an inkjet printhead to be designed in such a way that the relatively thick electrical contact lines are not in the ink drop ejection path between the drop ejector transducer and the corresponding nozzle. Such a design thereby minimizes any visible defects due to misdirected satellite drops.

Low topography thermal inkjet drop ejector structure

A printhead and method of fabrication thereof provides that the printhead reservoir has substantially the same cross-sectional ink flow area as the total cross-sectional area of the plurality of individual ink channels which interconnect the reservoir with the printhead nozzles. Since the flow area of the reservoir is substantially matched to the total flow area of the channels, the ink capacity of the reservoir is relatively low and the flow rate therethrough during a printing operation is relatively high. The small capacity of reservoir, together with the high ink flow rate therethrough, assures short ink residency time during printing, so that any exsolved air bubbles in the ink are swept away with subsequent ink droplet ejections during a printing operation and thus prevents any air bubbles present from coalescing into larger bubbles which can cause print quality defects.

Ink jet printhead which prevents accumulation of air bubbles therein and

An ink jet printhead is disclosed which has a heater plate containing the heating elements and driving circuitry means monolithographically formed on one surface thereof and the ink flow directing channel structure is formed on the heater plate using a layer of patternable polymeric material which, in one embodiment, is exposed using a mask to define the channel pattern then developed and cured. After curing, the patterned channel structure is polished to provide a smooth coplanar surface and a cover plate with an aperture therein is aligned and bonded to the channel structure to complete the printhead. The aperture serves as both ink inlet and a portion of the ink reservoir. The channels are open at one end and serve as the droplet ejecting nozzles, while the other ends are closed and extend beneath the cover plate aperture to provide a baffled portion of the ink reservoir and prevent cross-talk between the ink channels. In another embodiment, the channels ends opposite the nozzles open into a common recess with the channels walls extending therein to function as baffles and prevent cross-talk.

Ink jet printhead having a low cross talk ink channel structure

A thermal ink jet printer including a frame, a printhead mounted to the frame for printing ink images onto a heated and supported substrate, and an efficient substrate heating and supporting assembly mounted to the frame. The efficient substrate heating and supporting assembly includes a heating device, and a substrate supporting member having a front surface including a substrate supporting area for supporting substrates of various sizes one at a time and border areas having a polished finish. The efficient substrate heating and supporting assembly also includes a heat absorbing back surface facing the heating device. The heat absorbing back surface includes an increased heat absorbing area located opposite and centered relative to the substrate supporting area on the front surface. The increased heat absorbing area, relative to a rest of the back surface, has a coat of paint thereon for increasing heat absorption thereinto from the heating device, thereby resulting advantageously in relatively nonuniform heat absorption into the back surface, and relatively in more uniform, adequate and efficient substrate heating and drying temperatures on the front surface, when continuously running a most often run size of substrates.

Ink jet printer having an efficient substrate heating and supporting

A transparency for ink jet printing is enhanced for use as an ink jet recording medium by increasing the hydrophilicity of the coating formed on a transparent substrate. In one embodiment, the coating is subjected to a corona plasma discharge exposure to create changes in oxygen functionality at the coating surface resulting in increases in surface hydrophilicity. In another embodiment, the surface is exposed with UV radiation and ozone exposure for controlled periods of time. In both cases, the surface hydrophilicity is increased by generating highly reactive free radical oxygen (O.sup.-) which results primarily in increases in the oxygen functional groups C.dbd.O and COO.sup.-.

Method for increasing hydrophilicity of transparencies used as recording

An ink jet printing system utilizes a heated rotary printing drum for mounting and carrying paper to be printed by one or more thermal ink jet printheads to achieve black or full color printing at high speed. As printing and drying are achieved prior to any transfer of the sheet from the drum, smudging of images is prevented. Such a printing system is capable of producing dried prints that can be immediately stacked and handled without smudging using slow-drying black inks and fast-drying color inks at speeds exceeding 10 pages per minute for color and 20 pages per minute for monochrome black text or images. Hold down of the sheet onto the drum can be achieved using vacuum or electrostatic forces to precisely retain the sheet on the drum until printing and drying are completed. Partial tone printing on multiple passes of the heated drum is provided to eliminate mottle on large solid areas. Heating of the drum can be performed internally or externally.

Heated drum for ink jet printing

A printing machine of the type in which liquid ink is deposited on a recording medium for printing gray scale images. The printing machine includes a printhead having ink ejecting nozzles of different sizes. Nozzles of the same size are arranged in groups and groups of nozzles are offset from one another. Ink drops of one group are deposited at locations corresponding to the points of a grid and ink drops of another group are deposited at locations corresponding to points not on the grid. Gray scale printing is achieved by the variation in drop size produced by different groups of nozzles as well as offsetting nozzles of one or more groups of nozzles from a reference group of nozzles printing on the points of a grid.

Gray scale ink jet printer

An ink jet printer is configured in a hybrid architecture wherein a full width printbar is combined with a partial width color scanning assembly to provide the capability of selectively printing in black only or, alternately, of producing color prints by operating the color scan assembly exclusively. The cost of the hybrid system, when compared to a full width color system using four full width printbars, is greatly reduced. Throughput time is reduced by providing the control circuitry for distinguishing between black only and color operation and selectively controlling the printer mode of operation. The hybrid architecture is particularly useful in a LAN system since it provides a mechanism for balancing the relative color versus black page decomposition speed limitations. Also, the hybrid architecture enables a relatively simple implementation of a checkerboarding technique to suppress banding in output prints.

Hybrid ink jet printer

An ink jet ink includes a colorant and a liquid component containing at least one of an epoxy and a vinyl ether. Water may also be dissolved in the liquid component. Preferably, the vinyl ether is ethylene glycol monovinyl ether. An ink jet recording process includes the steps of ejecting an ink jet ink, such as the inks of the present invention, from an orifice to form an image on a recording medium.

Ink jet ink compositions and recording processes

A thermal ink jet printhead is controlled to minimize missing droplets at elevated operating temperatures by varying the voltage and pulse width applied to the heater element that causes droplets to be formed and ejected. Increasing the applied voltage reduces the size of the formed droplets. At increased operating temperatures, smaller droplets minimize the introduction of air into the nozzles of the printhead upon ejection. Minimizing the introduction of air eliminates printhead misfirings and causes more consistent jetting of the ink droplets.

Minimization of missing droplets in a thermal ink jet printer by drop

A method for removing kogation deposits or other materials from the heater element of a thermal ink jet printer includes selecting a pulse voltage, pulse width and number of pulses, and apply the selected number of pulses at the selected pulse voltage and pulse width to the heater element to disrupt the kogation deposits. An apparatus for removing kogation deposits or other materials from the heater elements of a thermal ink jet printer includes a controller and a voltage supply, such that the voltage supply is controlled by the controller to supply a selected number of pulses at a selected pulse voltage and a selected pulse width to the heater elements.

Method and apparatus for kogation removal from a heater element of a

A capping device for an ink-jet printhead having a nozzle opening defined in a surface thereof. A deformable member is urged into engagement with the surface at a predetermined pressure, causing a portion of the deformable member to be deformed into the nozzle opening to seal the nozzle opening of the printhead.

Zero-volume maintenance cap for an ink jet printhead

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Webster, NY, United States of America

Dale R Ims