Hewlett-packard Development Company, L.p.

Hewlett-packard Company

Ferran Vilanova

Miquel Boleda

Marc Serra

Pau Soler

James L McCullough

Salvador Sanchez

Ramon Borrell

Michel Encrenaz

Lionelle Grandmougin

Jes&uacute;s De La Lama

To translate a physical color to a color space of a printer device, a color patch is scanned using a printer's internal scanner. The printer then automatically prints that scanned color, together with a range of variations of that color, on the print media on which printing is to occur. A user may quickly and easily select a color match from the range of colors printed, by visual inspection. The user enters the selected color into the printer, using for example a number or position code, or by marking the selected color on the print media, which is then re-scanned by the printer. Thus, an iterative prior art manual procedure of color modification using color data determined by spectrophotometers is avoided.

Spot color application in printer device

Absolute perceptual values are stored in the design lab, for maximum-density-tone cutoffs&#x2014;preferably a maximum yellow-blue chrominance b* for yellow and minimum luminosity L* for other colorants. Automatic field operations in each printer then force the printer to subsequently print nominal full-saturation colorants so as to match the stored values. In addition to the stored cut-offs, black-and-white reference values measured in the printer are also used in linearizing printer response, for specific combinations of printing medium and printmode.

Closed-loop color correction using factory-measured color cutoffs anchored to field-measured white point

In a method of printing with overlapping printhead dies, artifacts in the printed image caused by the printing nozzles in the overlapping region are removed, either by measuring the width of the band produced in the overlapping region and selecting an appropriate depletion or propletion printing mask for subsequent printing operations, or by printing out a test pattern in which areas corresponding to a range of depletion and propletion masks are printed out and the optimal mask is selected for subsequent printing operations. The dies overlap by only a few rows of nozzles. The method may be employed in fixed printhead apparatus (e.g. page wide arrays) or in a scanning printhead apparatus.

Hardcopy apparatus and method

Computation and data-storage are minimized in both accounting for element condition and reallocation of print tasks away from subnominal elements. An accounting function maintains an element-condition tabulation partly in a cumulative form&mdash;representing element stability directly without later interpretation. A reallocation distributes print burden from a subnominal element to plural other elements without making a new mask. Rather, entries for a poor element in a current mask are shifted prospectively and quickly to other elements serving the same pixel rows.

Streamlined real-time printmask revision, and printing-element data system, to circumvent element malfunction

Techniques for printing ink drops in an inkjet printer, where at least one color ink can be printed by two (or more) printheads. The drops to be printed are divided between the two printheads with purposes of higher printer velocity, higher image quality and higher print reliability.

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Barcelona, Spain

Ferran Vilanova