Method for automatically forming ink and media-dependent color transforms for diverse colored inks and ink types, validating color gamut, and applying said inks

• Main Authors: Wickham, Mark H, Dreizin, Yuri A, Jennen, Steven R
• Format: Patent
• Language: English
• Published: 16.07.2002

The present invention relates generally to the field of non-impact printing and, in particular, the present invention reveals a method for automatically creating custom ink and media-dependent transforms so that a print engine operated under computer control is capable of autonomous operation by determining ink color and maximum percent ink coverage of a media (and therefore ink mixing ratios) and applying that knowledge to produce and 'sense' color values of a plurality of colored ink patches; a custom ink and media dependent transform is thus created using the 'sensed' color values of the patches and the transform is then used during printing operations to accurately expel a wide variety of ink colors from a plurality of print heads, at optimum percent ink coverage for a given media, in a large format full-color ink jet print engine. The method and apparatus of the present invention increases the color fidelity and precision for controlling a plurality of cartridges that emit an extremely wide variety of colored ink droplets from twelve (12) high resolution ink jet print cartridges, or pens, onto unique printing substrates during print operations in a large format digital print engine. The present invention provides an automated method of creating customized, ink and media-dependent color transforms to enable optimized printing operations. In the preferred embodiment, a charge coupled device (CCD) illuminated by an array of carefully chosen light emitting diodes (LED) is used to generate color coordinates of each of a plurality of colored patches printed on a printing substrate. The LED array provides a source of illumination upon a portion of a printed substrate within the field of view of a CCD/lens assembly that covers approximately the 400 to 700 nanometer wavelength of light (the "visible spectrum"). The LED array is used as a color sensor useful for revealing chromatic coordinates of inks in the print heads of the print engine, of printed patches that combine inks, and the maximum percent ink coverage of the media; thereby allowing the automatic creation of ink and media-dependent color transforms for the ink and media then-present on the print engine.