Sony Corporation

Apple Inc.

Sony Electronics Inc

Karl Lang

Rafael Calderon

Don L Moore

Paul Doyle

Matthew C Boyko

Andrew Bryant

Martin Kolinek

Roy Bragadeste

Nancy Wang

Mike McKay

Print performance is evaluated by printing a diagnostic image comprising color patches. Colorant usage in the printed image is measured by, for instance, scanning each patch. Measured color values are then compared to target color values. Based on the comparison, groups of patches whose color values vary significantly from expectations are identified. Variant groups are then analyzed to identify, in addition to color quality control problems, spatial problems that affect only a localized area of a printed page. Such spatial problems may include, for example, problems with contrast or streaks. A heat map illustrating the differences may be generated to help an operator visualize the spatial problem. A template for the diagnostic image may be selected from a plurality of randomly generated diagnostic targets based on total colorant usage for at least one colorant in each column of color patches. Certain patches may be predefined across for each candidate target.

Diagnostic targets for evaluating printing performance

A color calibration system includes a visual display terminal (VDT), a color calibration sensor optically coupled to the VDT, and a computer processing unit (CPU) electrically coupled to the VDT and the color calibration sensor. The VDT has a display screen and a plurality of color channels, each color channel having an intensity input, a bias input, and a gain input. The VDT produces an image on the display screen responsive to the intensity input. The color calibration sensor provides values responsive to the chromaticity and luminance of a test patch portion of the image on the display screen. The CPU performs calibration of the VDT including setting the bias of each color channel to reduce the difference between a target black point and the test patch with the intensity input at a minimum value for each color channel.

Color reference system for display monitor

Growing community of inventors

Madison, WI, United States of America

Karl Lang