Hewlett-packard Development Company, L.p.

Behnam Bastani

David Herbert Donovan

Bryan S Ly

Alejandro Campillo

Jorge Miguel Gomez

David Luis Pereira

Jose Ramos

Alejandro Campillo Agusti

Bryan Ly

Embodiments of printer optical sensing error determination are disclosed.

Printer optical sensing error determination

Systems and methods for print head calibration. In an exemplary embodiment, the method may include scanning an image on a print media to obtain an optical density profile. The method may also include selecting at least one window in the optical density profile. The method may also include generating an average profile for each window. The method may also include identifying variations in uniformity.

Systems and methods for print head calibration

A method of printing comprising: storing a plurality of sets of linearization data () for a printhead () with each set corresponding to a different history of usage of the printhead; monitoring (S) the history of usage of the printhead; selecting (S), prior to printing, from said plurality of sets of linearization data a set of linearization data that is the set that most closely matches the monitored history of usage of the printhead prior to said printing; and printing (S) the image using the selected set of linearization data.

Printing using stored linearization data

A method for density error correction is disclosed. In one embodiment, the method includes a) calculating an average density error for at least one row of an image considering density errors for printhead elements employed to print the at least one row, and a number of passes that the printhead elements will utilize to print the at least one row, b) calculating a density error correction value for the at least one row considering the average density error, and c) applying the density error correction value to adjust ink flow from the printhead elements while printing the at least one row.

Density error correction

One exemplary embodiment is a method that performs a calibration process for determining a number of spit and wipe operations to place each of multiple dies on a print cartridge in a stable state.

Calibration process for multi-die print cartridge

A method, apparatus, and computer program for calibration of a printer having a printed head with multiple dies creates linearization tables that compensate for different drop weight uniformities printed by die-to-die boundaries. The linearization tables are provided to a calibration routine to create an actual linearization table for ink printed by a die-to-die boundary of the print head. The calibration routine creates an actual linearization table by determining a measurement related to drop weight uniformity when the die-to-die boundary of the print head prints the ink. Based on this measurement, a pre-built linearization table is selected for compensating output drop weight and for allowing printing with a substantially uniform drop weight across the die-to-die boundary of the print head.

Calibration of a print head having multiple dies

A system for detecting pen-to-paper spacing (PPS) in a printing system having a pen attached to a moveable print head positioned near a print media position, includes a test pattern, at the print media position, a sensor device, attached to the print head, and a controller. The test pattern includes printed lines having a line dimension, and the sensor device is positioned to shine light upon, and detect light reflected from the test pattern as the print head scans across the test pattern. The controller is connected to receive reflectance signals from the reflectance sensor, and configured to determine line dimensions in the test pattern and compare said line dimensions with predetermined line dimension values for the test pattern to determine variation in the PPS.

Growing community of inventors

San Diego, CA, United States of America

Behnam Bastani