Hewlett-packard Development Company, L.p.

Hewlett-packard Company

David M Wetchler

Wesley R Schalk

Kevin Lo

Stephen G Brown

Dan R Dwyer

Mark M Proia

Jason M Quintana

Wen-Li Su

James M Brenner

Winthrop D Childers

William James Allen

Mark S Hickman

Michael L Bullock

Erick Blane Kinas

Iranpour Khormaei

George C Ross

Steven O Miller

Joseph H Bauman

Kenneth W Peterson

Imaging device

The present invention uses various real-time monitoring and resultant data inputs to change the print mode, dynamically during print cycles. Note that as a result of real-time monitoring and print mode adjustment, predetermined primary default print modes can be set a higher performance level. Various feedback subsystems provide real-time information critical to selecting specific print mode operational parameters, or 'Operational Attributes.' The attributes allow the print mode to be fine tuned, dynamically, for each printer and pen combination over the life of the printer. Thresholds that signal a print mode change are defined.

Dynamic ink-jet print mode adjustment

A multiple ink jet printing system comprising a plurality of rows of dark dye nozzles and light dye nozzles. Each row of dark dye nozzles is coupled to a supply of dark dye ink, and each row of light dye nozzles is coupled to a supply of light dye ink. Each of the rows of dark dye nozzles and light dye nozzles are arranged substantially parallel to each other, and at least one row of dark dye nozzles is separated from the next row of dark dye nozzles by at least one row of light dye nozzles.

System for reducing the effect of aerodynamic induced errors in a drop-on-demand printing system

Ink-jet pen drop firing elements having extended use&mdash;namely, printheads used with a plurality of replaceable reservoirs&mdash;are provided with a more accurate life span and performance gauge by monitoring energy accumulations over time and using monitored data for certain printer activity or maintenance.

Ink-jet printing and servicing by predicting and adjusting ink-jet component performance

A system is provided for use in a printer, the system including a media width sensor which is configured to sense the presence of media at a predetermined transverse position within the media path. By sensing media at such predetermined transverse position, it is possible to determine media width, and thus to identify media type. Correspondingly, it is possible to adapt media handling to address particular characteristics of the media, namely, thickness of the media and width of the media sheets.

Media handling system

A method of reducing pixel density in pixel array printers, alternatively termed depletion, uses information about a pixel when it is first available instead of having to recalculate that information at a later time. According to embodiments of the present invention, the process of identifying edge pixels for the purpose of depletion is performed during a halftoning process, in which every pixel in a pixel data array is examined. Pixels are classified as one of four possible pixel states: a blank pixel, a left/right edge pixel, a top/bottom edge pixel, or an area-fill pixel. The pixel state information is stored in a modified pixel data area. A predetermined pattern of filled and unfilled smaller pixels is identified with each pixel state. Each element in the modified pixel data array is mapped onto the smaller pixels according to the predetermined pattern and a printer is controlled according to the resulting pattern.

Multi-level pixel density reduction for printers

In one embodiment of the present invention, for a two-pass print mode, instead of two or more color printheads depositing the same amount of ink for each pass, one of the passes (the primary pass) in a predetermined direction deposits a substantial majority of the ink, and other pass (the secondary pass) deposits the remainder of the ink. The primary pass for a particular composite color must always be in the same direction for minimizing color shift, at least when printing contiguous swaths of the same color. For minimizing color shift, the choice of a direction for the primary pass can be arbitrary, related to performance, or related to the order of the primary colors in the carriage. This majority ink pass will dominate the ink effects and cause color shifts to be less perceptible. The amount of ink per pass may be determined on an empirical basis. This technique of depositing more ink dots during a pass in a predetermined direction applies to any number of passes, but is particularly applicable to two-pass print modes.

Multiple pass color shift correction technique for an inkjet printer

A method of automatically optimizing the controllable parameters related to producing printed material on a hardcopy output device is provided, along with a hardcopy output device configured for implementing this method. Users require different types of printed objects to have different characteristics. Specifically, business graphics need to be sharp and vivid, photographic images should look realistic, and text must be black, crisp and clear. By extracting, analyzing and conditioning data generated during a printing stream, the various regions of text, graphics and photographic images on a sheet are distinguished, characterized, and printed. The resulting hardcopy output has a custom balancing of color which is pleasing to the human eye for each type of image printed, and which has print characteristics tailored for the specific elements on the page.

Automatic optimization of hardcopy output

One aspect of the present invention is a color printing system that is responsive to color information for forming images on media. The color printing system includes a determining device that determines colorant usage for a plurality of colorants. The determining device detects a balanced condition wherein colorant usage is within a nominal range and an imbalanced condition wherein colorant usage exceeds the nominal range. The color printing system also includes a colorant balancing device. The colorant balancing device responds to the imbalanced condition for altering colorant usage for compensating for the imbalanced condition.

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Vancouver, WA, United States of America

David M Wetchler