Granted Patent
Utility
US 4,832,855 · App. 07/137,216
Immersion oil for microscopy
Inventor:
Toshiaki Tanaka
Patented Case
View Patent ↗
Granted: May 23, 1989
Filed: Dec 22, 1987
Inventor
Toshiaki Tanaka
Assignee (at issue)
Idemitsu Petrochemical Co., 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.