Granted Patent
Utility
US 4,849,172 · App. 07/148,153
Optical sensor
Inventors:
Masao Yafuso, Cheng F. Yan, Henry K. Hui, William W. Miller
Patented Case
View Patent ↗
Granted: Jul 18, 1989
Filed: Jan 29, 1988
Inventors
Masao Yafuso
Cheng F. Yan
Henry K. Hui
William W. Miller
Assignee (at issue)
Minnesota Mining and Manufacturing Company
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.