Granted Patent
Utility
US 4,656,021 · App. 06/854,525
Method for the production of silicon
Inventors:
Yasuo Tanabe, Minoru Tamura
Patented Case
View Patent ↗
Granted: Apr 7, 1987
Filed: Apr 22, 1986
Inventors
Yasuo Tanabe
Minoru Tamura
Assignee (at issue)
Mitsubishi Chemical Industries, 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.