Granted Patent
Utility
US 6,538,677 · App. 09/854,636
Apparatus and method for gray level printing
Inventors:
John R. Thompson, Yee S. Ng, Eric K. Zeise, Hwai-Tzuu Tai, Eric C. Stelter
Patented Case
View Patent ↗
Granted: Mar 25, 2003
Filed: May 14, 2001
Inventors
John R. Thompson
Yee S. Ng
Eric K. Zeise
Hwai-Tzuu Tai
Eric C. Stelter
Assignees (at issue)
Heidelberger Druckmaschinen AG
NexPress Solutions LLC
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.