Patent attributes
A diagnostic technique allows an easy visual detection of poor media advance calibration. The diagnostic technique employs a print mode that prints different areas of the plot at different passes with a controlled amount of advances between them. The dot positioning error in the different areas has a non-systematic nozzle contribution, that tends to cancel out, and a systematic contribution due to the accumulative media advance error. Different patterns can be used to make the dot positioning error due to the accumulative media advance error show up. By increasing the number of media advances between the printing of sets of pixels, e.g. pixels in a horizontal line, the effect of accumulated errors and the apparent visual effect is increased.