Granted Patent
Utility
US 4,869,840 · App. 07/170,471
Pyroelectric ceramics
Inventors:
Paul C. Osbond, Catherine S. Oswald, Roger W. Whatmore
Patented Case
View Patent ↗
Granted: Sep 26, 1989
Filed: Mar 21, 1988
Inventors
Paul C. Osbond
Catherine S. Oswald
Roger W. Whatmore
Assignee (at issue)
Plessey Overseas Limited
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.