Patent ID: 7407246
Filing Date: 2008-08-05
Classification: B41J

Abstract:
1. A greyscale printhead comprising: a nozzle plate, an ink chamber, and a source of ink; means for generating ink drops to be ejected from the greyscale printhead; drive circuitry for driving the means for generating ink drops by using different waveforms having a different number of pulses, the number of pulses being proportional to the volume of the ink drop; wherein the drive circuitry, when operated, drives the different waveforms with a single voltage, and the printhead includes means for storing waveform parameters characterizing a width of each of the different number of pulses of the different waveforms and a time between two subsequent pulses of the different waveforms such that said ink drops of a different volume, ejected from said printhead, have a velocity substantially the same within a tolerance of 25%.