Granted Patent
Utility
US 4,497,557 · App. 06/392,315
Electromagnetic shutter mechanism
Inventor:
Christian C. Petersen
Patented Case
View Patent ↗
Granted: Feb 5, 1985
Filed: Jun 25, 1982
Inventor
Christian C. Petersen
Assignee (at issue)
Polaroid 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.