Hewlett-packard Company

Hewlett-packard Development Company, L.p.

Frank Drogo

Ronald Albert Askeland

Clayton L Holstun

Brian P Canfield

Eric Joseph Johnson

Eric Stephen Mattis

Paul E Martinson

John Ferraro

Mark S Hickman

Keshava A Prasad

John L Stoffel, Jr

W Wistar Rhoads

Leonard Slevin

Michele E Shepard

Steve Castle

Winthrop D Childers

Brian J Keefe

Steven L Webb

Kenneth J Courian

Steven T Castle

Jaime H Bohorquez

Hanno Ix

Kai Kong Iu

Shailendra Kumar

William Wistar Rhoads

Susan Tousi

Barbara Parcells

A wet-wiping printhead cleaning system for inkjet printer incorporating a wiper for wiping the printhead including a treatment fluid applicator configured for placing treatment fluid onto at least one element of the printhead and wiper elements involved in wiping the printhead orifice plate surface, the treatment fluid being placed on said at least one element by direct contact of the applicator, subsequently the wiper wipes the printhead, the treatment being available to enhance cleaning effectiveness, the treatment fluid lubricating the wiper so as to lengthen wiper service life and enhance wiping performance, as well as acting to render unwanted accumulations on the printhead more removable by wiping.

Servicing system for an inkjet printhead

In a inkjet print cartridge ink flows from the reservoir around the edge of the silicon substrate before being ejected out of the nozzles. During operation, warm thermal boundary layers of ink form adjacent the substrate and dissolved gases in the thermal boundary layer of the ink form the bubbles. If the bubbles to grow larger than the diameter of subsequent ink passageways these bubbles choke the flow of ink to the vaporization chambers. This results in causing some of the nozzles of the printhead to become temporarily inoperable. The disclosure describes a method of avoiding such a malfunction in a liquid inkjet printing system by providing a method for reducing residual air bubbles in an inkjet print cartridge by flushing the empty cartridge by passing carbon dioxide through the fill port or the ink ejection nozzles prior to filling the print cartridge with ink and thereby eliminating residual air bubbles from the print cartridge when the print cartridge is filled with ink.

Gas flush to eliminate residual bubbles

A color ink-jet printer is provided, with one pen for dispensing black ink onto a print medium and at least one pen for dispensing color ink onto a print medium. The pen for dispensing black ink is adapted to jet droplets of black ink of a first volume and the pen(s) for dispensing color ink are adapted to jet droplets of color ink of a second volume, with the first volume being larger than the second volume. Such a color ink-jet printer provides both superior text quality of the black ink and does not require as much ink volume of the color ink(s) as previous ink-jet printers.

Printer with pen containing a low dot spread black ink and a high dot

A color ink-jet printer is provided, with one pen for dispensing black ink onto a print medium and at least one pen for dispensing color ink onto a print medium. The pen for dispensing black ink contains a pigment-based ink and the pen(s) for dispensing color ink contain a water-miscible dye-based ink. Such a color ink-jet printer provides both superior text quality (black ink) and relative ease of service (color inks), since the black ink is used more than the color inks and thus tends to require less spitting due to its frequency of use. On the other hand, since the color inks are used less, the utilization of water-miscible inks, which require less spitting than pigmented inks to keep the nozzle clear, also require less spitting even with relatively lower frequency of use.

Color ink-jet printer with pigment black and dye-based color inks

A method of operating a thermal inkjet printer having a thermal inkjet printhead that includes the steps of selecting an ink drop volume, selecting a pulse width that will cause the thermal inkjet printhead to deposit an ink drop having the selected drop volume, and operating the thermal inkjet printhead with the selected pulse width and at an operating energy that is greater than a turn-on energy of the printhead for the selected pulse width.

Control of ink drop volume in thermal inkjet printheads by varying the

An inkjet printer system fires smaller ink droplets in a single-pass print mode to achieve addressible print resolution of 600 dpi in the carriage scan axis along with 300 dpi resolution in the media advance axis, without having to employ any dot-depletion algorithms. In one embodiment, the system provides a fast print mode which prints the smaller drops of ink on a 300 dpi grid in the carriage scan axis. In another embodiment, the system provides a single-pass color print mode wherein primary colors are printed with two color droplets of the same primary color in two adjacent sub-pixels on the 300.times.600 grid, and secondary colors are printed with two color droplets of different primary colors in two adjacent sub-pixels on the 300.times.600 grid.

Inkjet printer with increased print resolution in the carriage scan axis

Method for increased print resolution in the carriage scan axis of an

An inkjet printer has a pen holder for removably holding an ink pen, a detector circuit for detecting whether ink with a degraded quality is likely to be ejected by said ink pen, and a servicing circuit responsive to said detector circuit for causing an initial quantity of ink to be discharged from said ink pen to ensure that ink with a degraded quality will not be used during normal printing.

Servicing a newly-installed ink pen to eliminate uneven print quality

Growing community of inventors

San Marcos, CA, United States of America

Frank Drogo