International Business Machines Corporation

Imaging Technology International Corp.

Ross N Mills

Francis C Lee

Frank E Talke

Horst G Mossbrugger

John Campbell Scott

Robert Nolan Payne

Anthony Juliana

Francis Chee-Shuen Lee

Gary A Drago

Gary V Sturm

Jon-Christophe Bernard Febvre

Walter F Baier

James Elwood Kerr

Cynthia F Reeves-Janzen

Richard W Koepcke

Michael D Ries

Tiefa K Niweigha

In an electrostatic ink jet printer, all nozzles of a printhead are spaced generally the same distance from a moving paper print substrate. Three voltage levels are selectively applied to each nozzle of the printhead. As the paper moves past the printhead, a bias voltage Vb is applied to all nozzles which have a static protruding meniscus which shape is determined by a balance between the internal pressure, surface tension, and bias voltage. When the paper arrives at a print row, nonprinting nozzles have a shadow voltage pulse Vs, the 'shadow pulse,' applied thereto, and printing nozzles have a higher magnitude print pulse Vp applied thereto. The magnitude of the shadow pulse Vs causes an additional excursion of the ink meniscus to form at each non-printing nozzle. The higher magnitude of print pulse Vp causes an ink filament to move from a printing nozzle to the paper. The time duration of each print pulse is varied in accordance with an ink density parameter up to a range that is determined by the duration of the shadow pulse. The electrostatic field difference between nonprinting and printing nozzles (Vp-Vs) is of a low magnitude that inhibits ink filament deflection and ink volume differences due to crosstalk between nozzles.

Shadow pulse compensation of an ink jet printer

An ink jet printhead includes a nonconductive substrate into which a plurality of tapered nozzle holes are formed with the wide hole area coincident with an ink entry side and with the marrow hole area coincident with an ink exit side, and with an ink reservoir mounted on the ink entry side. A metal layer covers the interior of each nozzle hole, and also provides an electrical control-signal conductor on the ink entry side for each metallized nozzle hole. The metal layer also provides a tubular metal extension for each metallized nozzle, these extensions extending a common distance beyond the ink exit side. A plurality of metal conductors may be provided on the ink exit side to facilitate nozzle control using signal-multiplexing techniques, or a field compensation electrode may be provided on the ink exit side.

Ink jet printhead and method of making

A fluorescent dyed polymer member and a light source are structurally arranged in a manner to efficiently gather light from the light source and then transmit the gathered light to a light utilization device. Light from the light source is gathered over a large area that is occupied by the polymer member. This gathered light is transmitted through the polymer member to an edge portion thereof having a relatively small light emitting area. Light is then emitted as an external beam having a cross section that corresponds to the physical shape of the edge of the polymer member, for example a straight of linear footprint of light. The area brightness of this external beam is greater than the area brightness of the initial light source.

Light source

An ink jet drop-on-demand print head comprises a plurality of electromechanical transducers, and ink from a manifold is conveyed to the transducers. The fluid path between the transducers and the corresponding nozzle in the nozzle array comprises a resilient dual function means. The dual function means not only provides the fan-in section but also seals the fluid path in fluid tight relation without the use of any adhesive or bonding material.

Drop-on-demand print head using gasket fan-in

An ink jet drop-on-demand print head comprises a plurality of tubular piezoelectric transducers each having two electrodes formed by an electrically conducting coating. A housing member holds the transducers in a position which includes at least one row of transducers. A substrate includes a plurality of electrical conductors, and the substrate is positioned so that each electrical conductor is adjacent one of the electrodes. A resilient connector means is provided which is not conductive along its length but is conductive across its width, and the connector means is positioned to make contact with a selected one of the electrical conductors and only one of the electrodes of one of the transducers. In a specific embodiment, the substrate comprises a flat conductor cable, and in a second embodiment the substrate comprises a printed circuit board.

Drop-on-demand ink jet print head

An ink jet drop-on-demand printing system comprising an ink jet print head having an ink cavity supplied with a suitable ink. An electromechanical transducer is mounted in mechanical communication with the ink cavity, and a source of electrical signals is provided to selectively actuate the transducer to produce an ink drop of a selected size. To produce ink drops of a selected size the source of electrical signals produces one or more electrical drive signals each separated by a fixed time delay which is short with respect to the drop-on-demand drop production rate. Each electrical drive signal ejects a predetermined volume of ink and all the volumes of ink merge to form a single drop prior to the time the ink drops reach the print medium for printing.

Spot size modulation using multiple pulse resonance drop ejection

An ink jet drop-on-demand printing system having gray scale capability comprising a transducer having a plurality of separately actuable sections. Print data is provided which defines a selected drop volume and control means is provided which is operable in response to the print data to produce drive signals to selectively actuate a particular combination of the separately actuable sections of the transducer to produce a drop of the volume specified by the print data. To provide further control over the drop volume while maintaining the drop velocity within selected limits, the amplitude of the drive signals can also be varied. A further refinement can be provided by varying not only the amplitude of the drive signals but also the pulse width of the drive signals. In a first embodiment the transducer sections are of equal length, while the sections are of unequal length in a second embodiment.

Gray scale printing with ink jet drop-on demand printing head

A drop-on-demand ink jet printing apparatus comprising a print head having an electromechanical transducer mounted in mechanical communication with the fluid in a fluid chamber within the print head. The transducer is selectively energized with a drop ejecting signal so that one drop of ink is ejected for each drop ejecting signal. In addition the transducer is energized with a series of low amplitude excitation signals which serve to maintain substantially constant dynamic ink characteristics so that quality printing is produced especially during start-up of the apparatus. The excitation pulses can be asynchronous with respect to the drop ejecting signals or synchronous but delayed with respect to the drop ejecting signals. Isolation means are provided to prevent concurrent excitation of the transducer with both a drop ejecting signal and an excitation signal.

Dynamic control of nonlinear ink properties for drop-on-demand ink jet

A drop-on-demand ink jet printing method and apparatus in which the print head has an ink cavity which is filled with ink, and which has a nozzle designed so that ink does not flow out under static conditions. An electromechanical transducer is selectively energized in response to print data signals so that, when energized by an electrical signal, the transducer produces a pressure wave in the ink cavity sufficient to eject one ink drop from the nozzle for each signal above a threshold value. The nozzle is a strongly convergent nozzle and the ink has a viscosity up to 100 centipoise. In the preferred embodiment, the nozzle is formed by anisotropic etching in a silicon substrate. An array of print heads produces a line of high-resolution printing as the print head array is moved across a print medium.

Drop-on-demand method and apparatus using converging nozzles and high

A drop-on-demand ink jet printing apparatus in which the print head has an ink cavity which is filled with ink, and which has an orifice designed so that ink does not flow out under static conditions. A fluid inlet chamber is provided to receive ink from the ink supply and this chamber is separated from the ink cavity by a narrow gap. An electromechanical transducer is mounted adjacent the ink cavity and the inlet chamber. The transducer is selectively energized in response to the print data signals so that, when energized by an electrical signal, the transducer reduces the volume in the ink cavity to eject one ink drop from the orifice and substantially close off the narrow gap to substantially close the flow path from the ink cavity to the inlet chamber during the formation of the drop of ink.

Ink jet print head having dynamic impedance adjustment

The object of this invention is to purge any entrapped air from the ink cavity (17) and nozzle orifice (15) of the print head (10) of a drop-on-demand ink jet printer. Purging is accomplished automatically as a part of the start up operation and also if, during operation, the velocity V.sub.s of the ink droplets (26), as sensed by a sensor (41), drops below a preselected reference value V.sub.r. The print head comprises a tubular piezoelectric transducer (11). The transducer is energized with a series of pulses for a preselected short time period and at a repetition rate substantially equal to a resonant frequency of the ink cavity. This effectively purges any entrapped air from the ink system. Except during purging, the transducer operates asynchronously in drop-on-demand mode in response to discrete binary print signals.

Resonant purging of drop-on-demand ink jet print heads

A drop-on-demand ink jet printer in which the print head includes a cavity having a nozzle portion at one end and a transducer mounted to contract a wall portion of the cavity when energized by a suitable voltage drive pulse. The drive pulses are produced at a predetermined rate but at a selectively controlled amplitude in response to the print data. In cases where no drop is required to print the data, the drive pulse is at a lower amplitude than the threshold voltage level, and for the first drop to be formed following a time at which no drop was formed, the amplitude of the drive pulse is greater than the threshold voltage level. At steady state operation of producing drops in sequence, the amplitude of the drive pulses equals the threshold voltage level.

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Morgan Hill, CA, United States of America

Ross N Mills