Hewlett-packard Development Company, L.P.

Pau Soler

John A Underwood

Francesc Subirada

Johan Maurice Lammens

Rodolfo Jodra

Francisco Javier Rodriguez

Ferran Vilanova

Alberto Such

Marc Rossinyol

Roger Vinas

Francesco Subirada

The present invention relates to a printer and method for printing an image on a medium comprising a plurality of holes, said image enveloping at least one of said holes. According to an embodiment, the printer comprises a means for identifying the respective locations of the holes in at least a first part of the medium, a processor for adjusting at least a part of the image by removing image regions corresponding with the defined locations and at least one printer head responsive to the processor for printing the adjusted at least part of the image on the at least the first part of the medium.

Printer and method for printing an image on a medium comprising a plurality of holes

A portable document format (PDF) file includes a graphical object and a corresponding spot color space. The spot color space is represented by at least one spot color name and an alternate representation of the spot color with device-independent data.

Representations of spot colors

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

In a printing system, a hue shift compensation method includes the steps of: printing in a first direction a first color having a first color composition; printing in a second direction a plurality of second colors having varying color compositions; measuring with a color sensor the first and second colors; selecting one of the second colors approximating the first color and having a second color composition; and storing data corresponding to the second color composition as direction dependent color map data for use in printing in the second direction.

Printing apparatus and method for generating direction dependent color map

A printing system is linearized automatically using measurements made with a simple optical sensor, such as a line sensor, that is onboard the system. The printing system itself is for forming images on plural printing media. Because the optical sensor is not a calorimeter or even a true densitometer, the sensor requires calibration, preferably based upon measurements using real inks. In the past it has been considered a requirement that such calibration be performed separately using each of the print media that was to be used for printing images. Linearization according to the invention, however, refers to a single calibration of the sensor, that calibration being used in common for essentially all media&#x2014;even though the single calibration is performed with respect to exclusively a single one of the plural media.

Linearization of an incremental printer by measurements referred to a media-independent sensor calibration

Ramps are printed with ink of a particular color, and also nominally in that color but by inks of other colors. A measured actual-ink ramp is a standard to fix the other-colors ramp, and correct other printing in those colors. In one aspect a particular color is gray, actual ink black (K), and other-color inks magenta (M), yellow (Y) and cyan (C). In another aspect, actual ink is red (R), green (G) or blue (B); other colors M, Y and C in respective pairs. For gray/black, the K ramp is a zero-chroma standard to lower composite-black (cK) chroma below &#x2dc;2.5 &#x394;E. A sampling aspect prints for each gray tone plural cK-ink combinations preferably bracketing nominal gray values; and searches these for one nearest the particular gray&#x2014;or most closely bracketing it, for interpolation&#x2014;for best match. Bracketing is best optimized, by a color-space pattern centered on nominal. Other aspects are taught.

Printing a true-ink reference, and refining gray accuracy, for optimum color calibration in incremental printing

To compensate for color-calibration sensor drift, a measurement of bare-print-medium tonal value is taken in immediate time juxtaposition to each color test pattern; measured bare-medium tone is then used to correct color-patch readings. A line sensor or the like, on the scanning printhead carriage, is used for the reading. Preferably two such readings are taken, one at each end of each test pattern; ideally separate scans of the bare medium are taken without any test-pattern patch to develop longterm and short-term drift profiles, for refining the corrections. To compensate for calibration error due to runout in the carriage track&#x2014;particularly for wide-bed printers&#x2014;sensor response to bare medium is used to represent variations in carriage-to-medium spacing along the track; these variations are corrected in later sensor use.

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Barcelona, Spain

Pau Soler