Hewlett-packard Company

Hewlett-packard Development Company, L.P.

Mark D Lund

Jefferson Patrick Ward

Steven T Castle

Steven B Elgee

John A Underwood

Thomas B Pritchard

Lee Walter Jackson

Matthew Allen Shepherd

Jeffrey Allen Nielsen

Erik D Ness

Clayton L Holstun

Stephen William Bauer

Matthew David Giere

Dustin W Blair

Duane Martin Evans

David Lynn Burton

Kevin R Hudson

Steven O Miller

Bruce A Axten

Volker Smektala

Maxwell S DeHaven

Peter J Boucher

Rory A Heim

Ngoc-Diep T Nguyen

Charles S Woodruff

Scott A Norum

Geir Bjune

Nikholas Hubbard

Mike Burton

Robert W Sperry

Daniel Burton

Andrzei Romanski

Christina J Lindstrom

Garrett Clinton Waycaster

A non-transitory storage medium is disclosed herein. An example of the non-transitory storage medium includes instructions that, when executed by a processor, cause the processor to actuate a pick assembly of a media handling system to select a sheet of medium from a media stack and lower the media stack a predetermined amount and subsequently raise the media stack the predetermined amount upon failure to pick the sheet of medium from the media stack. The non-transitory storage medium may include additional instructions as disclosed herein. A media handling system and method of media handling are also disclosed herein.

Media handling system

A system and method for printing on media includes a printhead assembly, a memory, and a controller. The printhead assembly is configured to make physical print sweeps relative to print regions of the media and to print within the print regions during the physical print sweeps. The memory communicates with the printhead assembly and is configured to receive data associated with a logical print sweep. The data associated with the logical print sweep controls printing within a first print region of the media during a corresponding first physical print sweep. The controller communicates with the printhead assembly and memory. The controller initiates the first physical print sweep of the printhead assembly before all of the data associated with the logical print sweep is received by the memory.

Printing system and method

Embodiments of methods, apparatuses, systems and/or devices associated with multiplexing are disclosed.

Multiplexing

Embodiments of the invention involve modifying non-volatile data fields in the integral memory components of consumable cartridges (and, in some embodiments, data fields in the utilizing device memory) such that the consumable cartridges become compatible with only a small subset of utilizing devices, thereby substantially reducing their potential value to a thief or unauthorized borrower.

Consumable cartridge with theft deterrence features

A printhead for an inkjet printer having geometric features which reduce drop placement error of main and satellite drops ejected from the nozzles of the printhead. Nozzles that are tilted along an axis corresponding to the direction of scanning of the printhead while printing have reduced drop placement error in the orthogonal direction to the scanning, and create a breakoff velocity for the satellite drop that can cause the main and satellite drops to be placed in a coincident location on the medium in one of the directions of scanning, thus forming desireable round printed spots and reducing drop placement error in the scan direction. These improvements can be repeatably achieved for all nozzles. Nozzles with non-circular and asymmetric bores also reduce drop placement errors, particularly when these types of nozzles are also tilted.

Inkjet nozzle structure to reduce drop placement error

When black regions are adjacent to color regions, the adjacent black regions are encoded (rendered) at the resolution of the color regions (e.g., 300 dpi) even though the printer has the capability of printing black at a higher resolution (e.g., 600 dpi). To make full use of the 600 dpi resolution of the printer, the black pixels are separated from the color pixels. The 300 dpi resolution black pixel field is converted to a 600 dpi black image field. A window surrounding a selected group of (600 dpi) black/white target pixels is chosen. The pixels in the window are applied to a logic circuit having a plurality of logical conditions. As a result of the logic processing, values of each of the target pixels can be changed to a different pixel value to avoid jagged edges in the printed images, thereby providing a pseudo-600 dpi resolution for the target pixels. The logical operations are performed until all of the pixels have values determined by the logic circuit. The resulting processed pixel field provides a more satisfactory printed image. The window is selected so that the pixel fields can be represented by word-length data groups. Black pixels rendered at the higher resolution are generally unaffected by the logic circuit. Thus, black pixels are rendered at two resolutions but printed at the same resolution.

Resolution enhancement of half-toned black data transmitted with color data

Multiple algorithms are applied to expand input image data of a variety of lower resolutions to output image data of a variety of higher resolutions with enhanced text quality, particularly in the black datapath controlling an output device such as an inkjet or laser printer. Enhancement techniques include edge smoothing, bit stripping for large drop weight pens, and drop-weight based ink depletion. Embodiments provide algorithms that convert 600&times;600 dpi input resolution data to 1200&times;600 dpi output resolution image data or 300&times;300 to 600&times;300 dpi resolution (i.e., asymmetric 2:1 ratio resolution conversion along mutually perpendicular axes), including text edge smoothing, while causing minimal change to gray scaled (halftoned) data within images. The techniques can be applied to other resolutions as well. Some embodiments include unidirectional bitstripping that preserves 1200 dpi edges while applying output pixels at only 600 dpi from 1200 dpi resolution output image data. Some embodiments include drop-weight based depletion to adjust the average ink flux to 32 ng per {fraction (1/600)}th inch cell, thereby preventing excess ink application at high output resolutions, e.g., 1200&times;600 dpi. In various embodiments, operations are performed in hardware modules and/or performed cooperatively as an integrated process to meet system throughput requirements.

Pixel depletion technique

Multiple algorithms are applied to expand input image data of a variety of lower resolutions to output image data of a variety of higher resolutions with enhanced text quality, particularly in the black datapath controlling an output device such as an inkjet or laser printer. Enhancement techniques include edge smoothing, bit stripping for large drop weight pens, and drop-weight based ink depletion. Embodiments provide algorithms that convert 600&times;600 dpi input resolution data to 1200&times;600 dpi output resolution image data or 300&times;300 to 600&times;300 dpi resolution (i.e., asymmetric 2:1 ratio resolution conversion along mutually perpendicular axes), including text edge smoothing, while causing minimal change to gray scaled (halftoned) data within images. The invention applies to other resolutions as well. Some embodiments include unidirectional bitstripping that preserves 1200 dpi edges while applying output pixels at only 600 dpi from 1200 dpi resolution output image data. Some embodiments include drop-weight based depletion to adjust the average ink flux to 32 ng per {fraction (1/600)}th inch cell, thereby preventing excess ink application at high output resolutions, e.g., 1200&times;600 dpi. In various embodiments, operations are performed in hardware modules and/or performed cooperatively as an integrated process to meet system throughput requirements.

Multiple data manipulation algorithms for text quality enhancement

Disclosed is a system in an inkjet printer for determining the amount of a fixer to be applied to a medium. The system comprises a fixer generation circuit where the fixer generation circuit determines an amount of a fixer to be applied to a dot location on a medium based on an amount of ink to be applied to the dot location. A bloom encoder circuit is also disclosed for identifying amounts of fixer to be deposited adjacent to dot locations containing ink.

Fixer usage generation technique for inkjet printers

A method and apparatus for a test pattern used in the alignment of an ink-jet pen which deposits fixer fluid, or other clear ink precursor fluid, on print media uses the change in reflectivity caused by overprinting a series of positional-calibration indicia with colorant to obtain data with respect to deviations in a carriage-scan x-axis and a paper scan y-axis. Thus the invention measures distances between pens or nozzles.

Clear fluid ink-jet pen alignment

Printhead longevity is extended by more uniformly utilizing individual printhead printing elements. A preferred algorithm moves an active zone of printing elements uniformly down the printhead on successive print passes. If insufficient printing elements are available to print the next pass, the active zone is moved to a point near the top of the printhead determined by a modulo function.

Nozzle usage balancing for ink-jet printers

A printing system that adjusts to drop volume characteristics of pens installed within an associated printer. Each pen has a characteristic drop volume representing the typical volume of ink expelled by the pen in forming ink drops used to form output pixels. Up to a maximum of N drops are used to form each pixel. A printer driver receives print data for the printer indicating saturation values for pixel data to be printed. Based on an expected pen drop volume, each saturation value maps to a corresponding number of ink drops for that value. To reduce data volume sent to the printer, the range of zero to N drops is subdivided into levels, each level representing some number of drops per pixel, and this level data is sent to the printer. If the characteristic drop volume of the pen is different from the expected volume, the subdivision of levels can be adjusted to compensate for differences in drop volumes. A related method includes the steps of defining at least first, second, and third levels of printing saturation, where in the first, second, and third level are respectively ejected N1, N2, and N3 droplets of ink per pixel. This method includes receiving data related to a characteristic drop volume associated with the printing system, and setting the value of at least one of {N1, N2, or N3}0 in accordance with the received data. The characteristic drop volume may be stored within a memory associated with each pen.

Apparatus and method for printing compensation

An inkjet printer uses a printhead that passes repeatedly across a print medium in individual swaths. The printhead has individual nozzles that are fired repeatedly during each printhead swath to apply an ink pattern to the print medium. Before any given swath, the printer analyzes factors that might require a reduction in print density. Anticipated printhead temperature is one factor that might require a reduction in print density. The printer monitors the print density and peak printhead temperature during each printhead swath. It then uses these values to calculate, prior to each new swath, a maximum permissible print density. If a reduction in print density is required, the printer temporarily disables selected nozzles to produce a reduced-height swath rather than pausing between swaths or reducing the printhead velocity relative to the page.

Swath density control to improve print quality and extend printhead life

An apparatus and method of aligning different color print heads of an ink jet printer by printing a sequence of extended-area first alignment elements in a first color, then printing an overlaying sequence of extended-area second alignment elements in a second color. Each of the alignment elements includes an array of spaced apart printed lines. The first alignment elements are printed to nominal reference positions, and the second alignment elements are offset from the reference positions by differing amounts. The degree of overlap of the first and second color lines is readily visible, and the most thoroughly overlapped alignment element may be readily identified. The identity of this element may then be fed back to the printer to respond with electronic alignment measures.

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Vancouver, WA, United States of America

Mark D Lund