Hewlett-packard Company

Hewlett-packard Development Company, L.p.

Hewlett-packard Development, L.p.

Mark H Kowalski

Melissa D Boyd

Keshava A Prasad

Vladek P Kasperchik

Alexey S Kabalnov

David M Schut

David Michael Kwasny

Shirley Lee

Gary W Byers

Amiya K Chatterjee

Raymond J Adamic

James P Shields

Paul David Gast

George C Ross

Brooke E Smith

Michel Anthony Riou

Steven D Looman

Robert B McMaster

Combinations of cationic underprinting fluids and anionic ink compositions that together achieve improved color quality and image stability in ink-jet printed images.

Ink and underprinting fluid combinations with improved inkjet print image color and stability

A transparent, protective overcoat for a printed medium achieved with a thermal transfer material on a carrier ribbon that is heated and pressed to transfer a segment of thermal transfer material from the carrier ribbon onto the printable surface of a medium.

Clear protective overcoat for a printed medium

A transparent, protective undercoat for a printed medium achieved with a thermal transfer material on a carrier ribbon that is heated and pressed to transfer a segment of thermal transfer material from the carrierribbon onto the printable surface of a medium.

Protective undercoating for a printed medium

An ink transfer sheet and method for using the same. The transfer sheet includes a backing layer, a release layer on the backing layer, and an ink receiving layer on the release layer. The ink receiving layer contains a quaternary ammonium salt thereon or impregnated therein. To use the transfer sheet, an ink containing an anionic coloring agent is applied to the ink receiving layer, preferably using thermal inkjet methods. Thereafter, the transfer sheet is positioned on a fabric substrate. Heat is applied to the sheet which causes the release layer and ink receiving layer to adhere to the substrate. The backing layer is then detached from the release layer leaving the release and ink receiving layers (with the printed image thereon) on the substrate. This process transfers the image to the fabric substrate, with the image being stabilized by interactions between the quaternary ammonium salt and anionic coloring agent.

Method and apparatus for applying a stable printed image onto a fabric substrate

A method of printing an ink jet ink on a print medium is provided, wherein a printed image is formed that is both waterfast and smearfast. The method employs a water-insoluble colorant and comprises: (a) providing an aqueous-based ink containing at least one disperse, sublimation dye and at least one dispersant for dispersing the dye; (b) jetting the ink onto the print medium to form an intermediate printed image; and (c) subjecting the print medium to a combination of heat and pressure for a period of time to convert the intermediate printed image to the waterfast and smearfast printed image. The temperature is high enough to cause the disperse, sublimation dye to disintegrate and diffuse into the print medium, thereby diffusing the coloring agents out of the dispersant &ldquo;shell&rdquo; around the dye particulate and recondensing in the same place as solvent dyes, free of the dispersant. Solvent dyes are insoluble in water. Thus, the recondensed solvent dyes on the substrate are essentially impervious to water, and the printed ink attains a waterfastness and smearfastness not previously achieved in aqueous thermal ink jet printing.

Waterfast and smearfast inks using ink jet delivered dye sublimation dyes

A method of printing an ink onto a print medium is provided. In the method, two inks are employed, a first ink that includes at least one water-soluble color dye that has a first charge, e.g., anionic, and a second ink that includes at least one black pigment that has a second and opposite charge, e.g., cationic. The method comprises: (a) providing the first ink, which contains at least one water-soluble, anionic color dye and at least one surfactant; (b) providing the second ink, which contains at least one cationic black pigment; (c) printing in a first pass across the print medium the first ink; (d) printing the second ink over the first ink, totally covering and overlapping the first ink, whereby the cationic black pigment(s) reacts with the anionic color dye(s) to form an insoluble complex on the print medium, and the surfactant draws the vehicle into the print medium, thereby improving print speed, print quality, bleed, and waterfastness of the ink. A printed ink set is also provided. The printed ink set comprises the cationic black pigment-based ink printed over the anionic color dye-based ink.

Print speed, print quality, bleed, and waterfastness with cationic black pigments and underprinting with anionic dyes

One or more reactive color inks are printed under and over black text and graphics areas. That is to say, one or more reactive color inks are first printed in a selected area in which black text and/or graphics are to be printed, then the black text and/or graphics are printed, and finally one or more reactive color inks are then printed over the black text and/or graphics. The use of under- and over-printing of black text and/or graphics by reactive color inks improves several important characteristics of inkjet printing. Specifically, the following improvements are obtained: dry-time, finger smudge, media independence/print quality, waterfastness, strikethrough, less noticeable missing/misdirected nozzles, and no dedicated pens are required. Alternatively, either underprinting alone or overprinting alone may be used.

Printing of color ink under and over black text and graphics areas

Method for producing a multi-layer ink transfer sheet

A method for producing a clear, vivid and water-fast printed image on a substrate. An ink is used which contains a sublimable dye diffusion thermal transfer coloring agent. The substrate includes a backing layer and an ink absorbent layer on the backing layer. The backing layer is designed to receive the coloring agent therein after sublimation of the coloring agent. The ink is initially delivered to the ink-absorbent layer. The substrate is then heated to cause sublimation of the coloring agent and diffusion of the sublimed coloring agent into the backing layer. Pressure may also be applied during the heating process. In addition, the ink can be retained within an ink cartridge in a printer unit, with the cartridge having at least one ink ejector. Heating of the substrate may then be accomplished by a heating member in the printer unit which contacts the substrate.

Method for applying clear, vivid, and water-fast printed images to a

Method and apparatus for applying a stable printed image onto a fabric

An organic acid component is employed in a first ink-jet ink composition to reduce the pH differential required to render insoluble the pH-sensitive colorant of a second encroaching ink-jet ink composition. By inducing the precipitation of the pH-sensitive colorant, migration of the colorant is inhibited, thereby substantially reducing bleed between the pH-sensitive ink and the ink containing the organic acid (the 'target' ink). The organic acid component is employed at a concentration ranging from about 0.25 to 20 wt % and may be represented by such as acids as polyacrylic, acetic, glycolic, malonic, malic, maleic, ascorbic, succinic, glutaric, fumaric, citric, tartaric, lactic, sulfonic, ortho-phosphoric acid, derivatives thereof. Without the organic acid component, a pH differential on the order of at least 4 and more likely 5 units must exist between the pH-sensitive ink and the target ink to substantially eliminate bleed. By employing an organic acid in the practice of the invention, a pH differential on the order of only 1 to 3 units may be required. Therefore, assuming the pH-sensitive ink has a pH of about 8, the pH of the target ink could be as high as 7 in the practice of the invention as opposed to a pH of about 3 in the absence of an organic acid component.

Growing community of inventors

Westford, MA, United States of America

Mark H Kowalski