Granted Patent
Utility
US 4,598,174 · App. 06/670,084
Circuit for detecting keypad conditions in a microprocessor controlled telephone instrument
Inventor:
Karl E. Pommer, II
Patented Case
View Patent ↗
Granted: Jul 1, 1986
Filed: Nov 13, 1984
Inventor
Karl E. Pommer, II
Assignee (at issue)
GTE Communication Systems 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.