Hewlett-Packard Company

Oregon State University

State of Oregon

Robert J Miller

Young S You

An-Chung Robert Lin

James D Ingle

Howard S Tom

William R Knight

Howard H Taub

William J West

An orificeless thin film printhead for an ink jet pen which comprises a substrate having a plurality of vortex activators thereon, and ink dispensing means located adjacent to the substrate for providing a thin layer of ink of a controlled thickness over the surfaces of the vortex activators. A protective cover is disposed on the surface of the substrate and has one or more slots or other openings therein operative to expose the vortex activators during ink jet printhead operation. When each vortex activator is energized, the energy transferred from the surface of the activator into the liquid film creates a microjet and a shear force therein, followed by the formation of a vortex ring in the ink film. The vortex ring is in turn self-propelled at a relatively low velocity through the ink film to the free liquid surface thereby, producing stress at this surface to allow the high velocity ink at the core of the vortex ring to be efficiently transferred to an adjacent print medium with a high degree of directionality, thereby enhancing resolution and print quality on the printed media. In accordance with the present invention, vortex activators include, but without limitation, heater resistors, piston drivers, and piezoelectric cavities.

Orificeless printhead for an ink jet printer

A device for detecting substances in a liquid film by measuring chemiluminescence, fluorescence or absorption using techniques such as flow-injection analysis schemes, liquid chromatographies, and gas chromatographies. The device can be used as a micro-volume mixing or reaction substrate for a variety of measurements. The device comprises at least two film supports that are separated by a small gap. One or more applicators are positioned along the gap to supply fluids to the gap. The applicators are positioned near the gap at a spacing that is near the necking length of the fluid supplied by the applicator. A thin, continuous film of the mixture of fluids to be examined is supported in the gap between the film supports. The film extends through the examining chamber and through drop and overflow detection probes. Also disclosed is a mixing or reaction chamber which comprises an enclosable mainframe into which a plurality of applicators are butted near a gap defined between two film supports. The chamber communicates with an inlet port and an exit port for controlling the pressure and other aspects of the environment in the chamber.

Observation cell and mixing chamber

Disclosed herein are substantially homogeneous solid ink-jet ink compositions. The use of such compositions with colored transparencies substantially reduces the level of light scattering as compared to the level of light scattering arising from the use of non-homogeneous ink-jet ink compositions. It is also disclosed that further improvements in the ink-jet ink composition can be achieved by employing a cosolvent in the composition.

Solid ink compositions suitable for use in color transparencies

A single-pulse driver for a bubble driven ink jet ink having good staying power at operating temperature, the driver being a solvent for the ink carrier, having a molecular weight less than 150, a boiling point less than 140 centigrade degrees higher than its melting point and a boiling temperature not lower than 120.degree. centigrade.

Solid driver for the solid ink jet ink

A windowless flow cell for detecting substances in a flowing fluid stream by chemiluminescence, fluorescence or absorption in flow injection analysis schemes, liquid chromatographs, or gas chromatographs is described. Furthermore, the mixing characteristics of the invention suggest its use as a micro-volume mixing chamber for a variety of experiments. A windowless flow cell comprising an upper body plate, upper wire spacer, mid-body plate, lower body spacer plate, and lower body plate interconnected by anchor bolts is described. Cell wires are attached to the upper body plate and the lower body plate. A primary reagent port through the upper body plate, with secondary reagent port and tertiary reagent port through the mid-body plate provide the fluids to be mixed. A thin film of the mixture of fluids to be examined flows down the cell wires through the examining chamber and through the drop detector and overflow detector prior to exiting the drain port by way of a low vacuum source. A micro-volume mixing chamber comprising a plexiglass mainframe with viewing windows of an examining chamber into which a plurality of reagent ports flow to form a fluid film on cell wires is described. The examining chamber also comprises gas inlet ports for control of pressure and of the type of gas environment.

Windowless flow cell and mixing chamber

An orifice plate is thermally bonded to a thick film photopolymer spacer fabricated on a print head substrate using heat and compression. The compression is applied by pressurized gas to a pliable sheet covering the orifice plate and substrate assembly. Heat can be supplied through a vacuum chuck on which the assembly is mounted or from a heating element embedded in the pliable sheet. An apparatus comprising an air actuated ram with a flange having an o-ring seated within is used to seal the pliable sheet against the vacuum chuck circumferentially about the assembly. The ram includes a chamber with an open end which is sealed against the pliable sheet when in an engaged position. By filling the chamber with gas under sufficient pressure while heating the spacer forms a bond between the orifice plate and the assembly. After thermal bonding, curing of the photopolymer spacer can be completed in an oven.

Thermal-bonding process and apparatus

An improved ink suitable for use in ink-jet printers is provided. The ink includes (a) a vehicle comprising at least one member selected from the group consisting of water and a water-soluble, non-aqueous component, and (b) an anionic dye having cations associated therewith. The ink composition is characterized by further including a macrocyclic polyether associated with the cations, the macrocyclic polyether having binding sites and a cavity size suitable for complexing the cations. The ink composition of the invention evidences reduced crusting, increased fade resistance and, for use in thermal ink-jet printers, reduced kogation.

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Burlingame, CA, United States of America

Robert J Miller