Dennis P Parazak

US Patent:

6500880, Dec 31, 2002

Filed:

Oct 26, 2000

Appl. No.:

09/697902

Inventors:

Dennis P. Parazak - Corvallis OR

Assignee:

Hewlett-Packard Comapny - Palo Alto CA

International Classification:

C09D 1110

US Classification:

523160, 524284, 524320, 524321, 524403, 524417, 524419, 524429, 524519, 524520, 524521, 524555, 524560

Abstract:

The ink set of this invention comprises at least two inks, one of which contains a pH sensitive polymer and pigment colorant with dispersant. A second ink is provided which comprises incompatible inorganic or organic salts or has an appropriate pH. The polymer precipitates onto a medium upon contact with the second ink, thereby providing improved bleed control.

US Patent:

6540821, Apr 1, 2003

Filed:

May 4, 2001

Appl. No.:

09/848810

Inventors:

Raymond J Adamic - Corvallis OR
Mary E Austin - Corvallis OR
Hiang P Lauw - Corvallis OR
Dennis P Parazak - Oceanside CA
Zia Rehman - Corvallis OR

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

C09D 1102

US Classification:

106 3148, 106 3127, 106 3149

Abstract:

Color ink sets for use in printer systems are provided and formulated to provide improved plain paper and special media performance while maintaining good printing characteristics. The inks and ink sets of the present invention exhibit excellent color performance and lightfastness across a range of media, robust K/Y bleed resistance on plain paper at fast print speeds, as well as excellent printability and reliability. A specific dye set for formulating yellow, magenta, and cyan inks comprises a mixture of acid yellow 23 (AY23) and direct yellow 132 (DY132), a mixture of a cyan dye compound having the formula: wherein Pc represents a phthalocyanine nucleus and acid blue 9; and a magenta dye compound having formula: wherein Q is a cation.

US Patent:

6572690, Jun 3, 2003

Filed:

Mar 5, 2001

Appl. No.:

09/800450

Inventors:

Zia Rehman - Corvallis OR
Dennis P Parazak - Oceanside CA
Raymond J Adamic - Corvallis OR

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

C09D 1102

US Classification:

106 3158, 106 3186

Abstract:

Ink-jet ink compositions are described comprising a mixture of succinic acid and at least one second organic acid. The ink-jet ink compositions alleviate color bleed, and lead to reliable pen performance when incorporated in a pen architecture.

US Patent:

6648464, Nov 18, 2003

Filed:

Sep 6, 2002

Appl. No.:

10/236634

Inventors:

Dennis P Parazak - Oceanside CA

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

B41J 201

US Classification:

347100, 347 28, 347 95

Abstract:

The present invention is drawn to systems and methods for remediating printhead cross-contamination wherein at least one of the ink-jet inks has undergone crashing. Specifically, a method of minimizing or reversing crashing of a first ink-jet ink that has reacted with a second ink-jet ink on a printhead can comprise the steps of dispensing a reactive cleaning fluid that is chemically configured to react with the first ink-jet ink after crashing; and cleaning a printhead having a crashed inkjet ink thereon with the reactive cleaning fluid, thereby minimizing or reverse crashing at the printhead.

US Patent:

7246896, Jul 24, 2007

Filed:

Apr 12, 2004

Appl. No.:

10/823440

Inventors:

Ronald A. Askeland - San Diego CA, US
Dennis P. Parazak - Oceanside CA, US
Rodney Stramel - San Diego CA, US

Assignee:

Hewlett-Packard Development Company L.P. - Houston TX

International Classification:

G01D 11/00

US Classification:

347100, 347101, 347 95

Abstract:

Systems and methods for providing smudge resistant and durable ink-jet images are provided. Specifically, a system for printing durable ink-jet ink images can comprise a first printhead containing a fixer composition including a charged fixer component, wherein the first printhead is configured for ink-jet printing the fixer composition on a substrate. The system can further comprise a second printhead containing an ink-jet ink, wherein the second printhead is configured for ink-jet printing the ink-jet ink composition over the fixer composition. The ink-jet ink can also include a colorant carrying an opposite charge with respect to the charged fixer component. A third printhead containing a polymer overcoat composition can also be present, and can be configured for ink-jet printing the polymer overcoat composition over ink-jet ink composition. The polymer of the polymer overcoat composition can also carry an opposite charge with respect to the charged fixer component.

US Patent:

7387362, Jun 17, 2008

Filed:

Mar 18, 2005

Appl. No.:

11/084492

Inventors:

Dennis P. Parazak - Oceanside CA, US

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

B41J 2/135
B41J 2/015

US Classification:

347 45, 347 21

Abstract:

The present invention is drawn to methods and architecture for depositing one or more self-assembled monolayer(s) onto a print nozzle orifice plate surface. In particular, the servicing fluid includes a self-assembled monolayer-forming agent and is applied using a wiper. The wiper is configured to service and maintain an orifice plate surface having a pre-existing self-assembled monolayer, or for initial application of a self-assembled monolayer to an orifice plate.

US Patent:

7500742, Mar 10, 2009

Filed:

Oct 22, 2003

Appl. No.:

10/691714

Inventors:

Dennis P Parazak - Oceanside CA, US
James A. Mott - San Diego CA, US
Melissa D. Lee - Escondido CA, US
James Pingel - San Diego CA, US

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

B41J 2/17

US Classification:

347 96, 347100

Abstract:

Disclosed herein are method and systems for printing a reactive ink and a fixer or second reactive ink onto a substrate from a single orifice plate, wherein orifice plate comprising at least two orifices; wherein at least one orifice prints a first reactive ink, and other orifice prints a fixer or second reactive ink. The reactive inks and the fixer reacts to form a precipitate which soluble in at least one of the fixer or the inks.

US Patent:

7846245, Dec 7, 2010

Filed:

Nov 2, 2006

Appl. No.:

11/592439

Inventors:

Dennis P Parazak - Oceanside CA, US
Eduardo Amela - Barcelona, ES

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

C09D 11/02

US Classification:

106 3127, 106 315, 106 3148

Abstract:

Ink, ink sets, and methods of printing are provided. The inks can include a plurality of dyes such that upon printing on a print medium, the printed ink or inks can maintain a neutral color, defined by an a* value from about −1 to about 3 and having a b* value from about 3 to about −15. This neutral color can be maintained such that the printed ink or image has these a*b* values for substantially all L* values ranging from about 25 to about 75, or even from 0 to 95.