Granted Patent
Utility
US 5,804,821 · App. 08/856,605
Plasma ion source mass analyzer
Inventor:
Yoshitomo Nakagawa
Patented Case
View Patent ↗
Granted: Sep 8, 1998
Filed: May 15, 1997
Inventor
Yoshitomo Nakagawa
Assignee (at issue)
SEIKO INSTRUMENTS INC.
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.