Abstract: The present invention is generally directed to providing drop volume normalization of the ink jet nozzles in an ink jet printing operation to alleviate and/or eliminate banding effects due to imprecise placement of ink drops on the printed sheet and variations in the volume of drops produced by different ink jet nozzles of the print device. Exemplary embodiments relate to a method and apparatus for controlling a print device having at least one ink jet nozzle by adjusting an offset control of a power supply used to control drop volume of the at least one ink jet nozzle. In a print device configured with piezoelectric ink jet nozzles, the output drop volume of the nozzle can be controlled within a predetermined range by adjusting the voltage supplied to the ink jet nozzle. As those skilled in the art will appreciate, this offset control of drop volume will result in a change to output ink velocity as well.

Abstract: An improved method and apparatus for controlling an electrostatic plotter is disclosed which results in an increased speed for the plotter. This speed is achieved by dividing the picture to be printed into frames and processing the individual frames in parallel with separate controllers for each frame. The styli on the electrostatic printer's head will accordingly be divided into the separate frames. The raster data produced by each of the controllers is combined to form the entire picture and is forwarded to the plotter.