Granted Patent
Utility
US 5,255,246 · App. 07/945,918
Electroacoustic transducer of the electret type
Inventor:
Aart Zeger van Halteren
Patented Case
View Patent ↗
Granted: Oct 19, 1993
Filed: Sep 17, 1992
Inventor
Aart Zeger van Halteren
Assignee (at issue)
Siemens Nederland N.V.
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.