Printhead calibration and printing

Abstract

The invention relates to a method of printing a two-dimensional bit-mapped image having a number of pixels per row, the printhead having a row of ejection channels and each ejection channel having associated ejection electrodes to which voltages are applied in use. During printing, in order to cause volumes of fluid to be ejected from selected ejection channels of the printhead for printing, voltage pulses having values of predetermined amplitude and duration as determined by respective image pixel bit values generated by a raster image processor are applied, at a given pulse period, to the electrodes of the selected ejection channels. The part of the raster image corresponding to an ejection channel is scanned to determine the number of adjacent non-printing pixel periods prior to a pixel to be printed and, immediately prior to the printing of said pixel, a voltage pulse, having a value predetermined in accordance with the time, measured in units of the given pixel period, between the last pixel to be printed and said pixel to be printed, is applied to the ejection electrode.

Dependencies are inferred from the claim text.