US 6,982,812 B2
Calibration of printing devices
David A. Johnson, Boise, Id. (US)
Assigned to Hewlett-Packard Development Company, L.P., Houston, Tex. (US)
Filed on Jan. 22, 2001, as Appl. No. 9/767,613.
Prior Publication US 2002/0134130 A1, Sep. 26, 2002
Int. Cl. H04N 1/00 (2006.01); H04N 1/46 (2006.01)
U.S. Cl. 358—1.9 20 Claims
OG exemplary drawing
 
1. A method for calibrating a printing device, comprising the following steps:
(a) performing an on-media calibration, including the following substeps:
(a.1) placing colorant on print media,
(a.2) performing a measurement to obtain on-media calibration measured values of the colorant on the print media, and
(a.3) using the on-media calibration measured values to calibrate the printing device;
(b) performing an off-media calibration to obtain off-media calibration measured values of the colorant, the off-media calibration being performed without placing the colorant on print media;
(c) making a correlation between the on-media calibration measured values of the colorant placed on the print media and the off-media calibration measured values of the colorant placed on the print media; and,
(d) performing subsequent off-media calibrations by placing the colorant on other than the print media to obtain additional off-media calibration measured values which are used along with the correlation between the on-media calibration measured values and the off-media calibration measured values to calibrate the printing device.