Patent ID: 9669627
Date: 2017-06-06
CPC Classifications: B41J

Claim:
1. A method for driving a plurality of droplet ejection devices, comprising: generating a single multi-level waveform having a compensating edge or a compensating pulse in a first section that is associated with at least one pulse in a second section of the single multi-level waveform, the compensating edge or pulse is selected based on a spatial distribution of a droplet parameter across the plurality of droplet ejection devices and has a compensating effect to compensate for systematic variation across the plurality of droplet ejection devices; identifying first and second groups of the plurality of the droplet devices within the spatial distribution of the droplet parameter across the plurality of droplet ejection devices; mapping pixels of input image data that are associated with the second group of the droplet devices into a second level of the multi-level waveform while pixels of input image data that are associated with the first group of the droplet devices are mapped into a first level of the multi-level waveform; and applying the single multi-level waveform to the plurality of droplet ejection devices including using the first level of the single multi-level waveform having at least one drive pulse in the second section and no compensating edge or pulse in the first section for the first group of droplet ejection devices to eject one or more droplets and using the second level of the single multi-level waveform having at least one drive pulse in the second section and a compensating edge or pulse in the first section for the second group of droplet ejection devices to eject one or more droplets, wherein the at least one pulse in the second section of the single multi-level waveform comprises a plurality of drive pulses having a separation between adjacent drive pulses that corresponds to a resonance time period of the plurality of droplet election devices for electing the one or more droplets of a fluid.