Granted Patent
Utility
US 4,993,624 · App. 07/514,953
Two-way bar code window envelope
Inventor:
John Schlich
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Apr 26, 1990
Inventor
John Schlich
Assignee (at issue)
National Service Industries, Inc.
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.