Hewlett-packard Company

Hewlett-packard Corporation

David Charles Towery

Guo Li

Alan Eddy Cariffe

Mark A Overton

Francis E Bockman

Anne P Kadonaga

Iue-Shuenn Chen

Janet E Mebane

The present invention is embodied in a system and method for automatically calibrating the print contrast of an inkjet printing system using an optical-electronic sensor to detect an ink drop volume. The print contrast calibration system includes an optical-electronic sensor that obtains test pattern data from a printed test pattern, a calibration module that contains calibration data for the printing system, an installation module that determines a drop volume score by using the test pattern data and the calibration data and a printing module that determines a print contrast setting based on the drop volume score. The present invention also includes a method for calibrating print contrast in a printing system by storing standard calibration curves for the printing system, comparing the standard calibration curves with a printhead assembly calibration curve to determine a drop volume score, and setting the print contrast based on the drop volume score.

Calibration of print contrast using an optical-electronic sensor

Techniques are disclosed for depleting raster data to allow printing of the depleted raster data on a grid that corresponds to the resolution of the undepleted raster data with a printed dot size that is larger that would otherwise be utilized with the undepleted raster data and to achieve faster ink dry time. Also disclosed is a technique for up scaling raster data at a particular resolution (e.g., 300 dpi) to a higher resolution in such a manner that expanded data includes a greater number of dot producing pixels to compensate for a dot size that is larger than the dot size that is appropriate for the higher resolution, and does not require horizontal depletion for printing with such dot size. This allows raster data at a particular resolution to be combined with higher resolution rasterized vector data for printing in accordance with the enhanced mode of operation.

Double axis dot depletion for 600 DPI edge acuity with 300 DPI print

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San Diego, CA, United States of America

David Charles Towery