Granted Patent
Utility
US 6,094,549 · App. 09/159,785
Electrograph apparatus enabling removal of offensive substances
Inventors:
Chikara Hiraoka, Katsumi Kumada, Katsuyoshi Onose
Patented Case
View Patent ↗
Granted: Jul 25, 2000
Filed: Sep 24, 1998
Inventors
Chikara Hiraoka
Katsumi Kumada
Katsuyoshi Onose
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.