Granted Patent
Utility
US 4,935,908 · App. 07/412,602
Finding the direction of a sound
Inventors:
Martyn D. Bull, Philip G. Harper, Stuart I. Jardine, David M. Treherne
Patented Case
View Patent ↗
Granted: Jun 19, 1990
Filed: Sep 27, 1989
Inventors
Martyn D. Bull
Philip G. Harper
Stuart I. Jardine
David M. Treherne
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT CORPORATION
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.