Granted Patent
Utility
US 4,931,019 · App. 07/239,258
Electrostatic image display apparatus
Inventor:
Kyung-Tae Park
Patented Case
View Patent ↗
Granted: Jun 5, 1990
Filed: Sep 1, 1988
Inventor
Kyung-Tae Park
Assignee (at issue)
Pennwalt 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.