A system for printing gray levels without needing to use halftone cells. An architecture is disclosed for controlling printing elements to deposit a variable amount of toner onto a given area of paper. The architecture includes a pixel memory for determining a gray level for each pixel in a row, and...http://www.google.de/patents/US5193011?utm_source=gb-gplus-sharePatent US5193011 - Method and apparatus for producing variable width pulses to produce an image having gray levels
