Granted Patent
Utility
US 5,459,028 · App. 08/273,580
Photographic material developable by heat treatment
Inventor:
Walter Ball
Patented Case
View Patent ↗
Granted: Oct 17, 1995
Filed: Jul 11, 1994
Inventor
Walter Ball
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.