Hewlett-packard Company

Hewlett-packard Development Company, L.p.

An-Chung Robert Lin

Howard S Tom

Young S You

Robert J Miller

Michael H Lee

Si-Ty Lam

Robert C Leichner

Irwin Sobel

Young-Soo You

The present invention is drawn to colorless toner compositions for overcoating a print having an ink jet ink image printed thereon. The colorless toner can comprise: a toner resin and at least two additives independently selected from the group consisting of ultraviolet absorbers, free radical inhibitors, thermal stabilizers, and combinations thereof, wherein the ratio of toner resin to total additive is from 1:1 to 99:1 by weight. The colorless toner can also be comprised of a charge control agent and/or a low-melt wax.

Colorless toner formulated to improve light fastness of ink jet prints

Colorless toner formulated to improve light fastness of ink jet ink prints

An aqueous ink composition having insoluble dye dispersed uniformly throughout by means of a coupling/dispersive (dual function) agent. The coupling/dispersive agent is characterized by association with insoluble dye molecules as well as by solubilization in a water based carrier medium. The resulting ink is water fast because the coupling/dispersive agent probably evaporates during drying or migrates away.

Water fast ink jet print using aqueous ink jet ink

A special ink consists of water and a humectant. A reusable paper includes a surface darkened by a water-insoluble material and a coating covering the darkened surface. The coating is made of a material that scatters light when dry and that becomes at least translucent when wetted by water. If the special ink is used to print on the reusable paper, the print will be visible for a limited period of time (e.g., half an hour). By the end of that time period, however, the special ink will have evaporated and the print will have disappeared completely from the reusable paper. The special ink may be applied to the reusable paper by an inkjet printer. An inkjet cartridge for such a printer includes a casing filled with the special ink.

Inking system including reusable paper and water-humectant ink

This invention concerns a composition for use as an additive in an ink composition for an inkjet printer or a laserjet printer or as a coating on paper or plastic substrate used in an inkjet or laserjet printer which improves lightfastness and durability properties of the ink, which additive composition comprises: (A) at least one ultraviolet absorber, (B) at least one free radical inhibitor, (C) at least one antioxidant, and (D) at least one liquid carrier selected from the group consisting of water, organic liquid or combinations thereof. These compositions result in a print image that is more colorfast and durable than those of the conventional art.

Composition to improve colorfastness of a printed image

A method and an apparatus to electronically identify a page. Each page has a surface conductive trace that is coupled to an electronic circuit to measure the conductivity of the trace. The primary purpose of the conductive trace is to provide an identification for the page.

Page identification with conductive traces

An ink transfer printing device having improved ink dot size control. The ink transfer printing device includes an ink container for retaining ink and a perforated ink transfer surface coupled to the ink container. The ink transfer surface includes at least one concentric region on the ink transfer surface about each of the perforations to control the spread of the ink. The concentric regions form flow barriers which impede the spread of the ink at each orifice. The ink dot size control provided by the present invention facilitates continuous toning, gray scale toning and multi-color printing.

Ink dot size control for ink transfer printing

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.

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Cupertino, CA, United States of America

An-Chung Robert Lin