Granted Patent
Utility
US 4,489,310 · App. 06/383,079
Time slot-controlling circuit for keyboard switch module, and apparatus incorporating same
Inventor:
David Trostyanetsky
Patented Case
View Patent ↗
Granted: Dec 18, 1984
Filed: May 28, 1982
Inventor
David Trostyanetsky
Assignee (at issue)
AT&T Technologies Incorporated
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.