Granted Patent
Utility
US 4,983,864 · App. 07/328,854
Electronic beam drawing apparatus
Inventors:
Fumio Murai, Shinji Okazaki
Patented Case
View Patent ↗
Granted: Jan 8, 1991
Filed: Mar 27, 1989
Inventors
Fumio Murai
Shinji Okazaki
Assignee (at issue)
HITACHI, LTD.
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.