Granted Patent
Utility
US 4,209,819 · App. 05/885,873
Capacitive keyswitch
Inventor:
Ewald E. Seignemartin
Patented Case
View Patent ↗
Granted: Jun 24, 1980
Filed: Mar 13, 1978
Inventor
Ewald E. Seignemartin
Assignee (at issue)
Key Tronic 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.